Design Optimization and Cost Estimation of Hybrid Building Modules in AEC (Architecture, Engineering, Construction) Industry

Design optimization and cost estimation of

hybrid building modules in AEC industry

Master thesis

International Master of Science in Construction and Real Estate Management

Joint Study Programme of Metropolia UAS and HTW Berlin

Submitted on 20.01.2020 from

Shashank Pandey

S0562622

First Supervisor: Prof. Dr.-Ing. Dieter Bunte

. Second Supervisor: Mr. Frank Talmon l’Armée

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Abstract

As any industry, AEC industry is also gaining rapid transformation. Technology is play- ing a vital role in shaping our future buildings. From BIM, building automation to sustainable development models, we are witnessing a sea of change. The world population is growing, and major economies of the world (like Germany) attract migrant population to chip in this booming cycle. This in turn puts pressure on existing infrastruc- ture. More buildings are needed for varied purposes and at a fast pace. This opens the niche of modular construction to fill in this gap. Modular construction is not only fast but also cheaper, more efficient, sustainable, bears high quality, reduces risk, enhances safety and promotes lean construction.

This thesis focused on studying historic development in the field of modular construction. Recent developments and case studies (local and international) highlights the current market trends and standards. Also benefits and limitation of modular construction have been highlighted upon. These learnings were then utilized to create an opti- mized design model of a residential building. This thesis work was done in collaboration with SEMODU AG. Author hence tried to implement SEMODU’s vision of hybrid modular construction into this work. After analyzing various building material, a combination of wood and RCC construction was established to bear maximum benefits.

This modular design was also compared with the conventional construction system for cost and time assessment. The direct and indirect benefits of such a model have been illustrated in this work.

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Table of Contents

Abstract ...... - 4 -

Table of Contents ...... - 5 -

Table of Figures ...... - 7 -

List of Tabulations ...... - 10 -

List of Abbreviations ...... - 11 -

Introduction ...... - 12 -

1.1 Definition and Brief ...... - 12 -

1.2 History of modular construction ...... - 15 -

1.3 History of modular construction in Germany ...... - 24 -

1.4 Benefits of modular construction: ...... - 28 -

a) Time Saving ...... - 28 -

b) Offsite Construction & Flexibility ...... - 30 -

c) Quality, Damage & Risk ...... - 31 -

d) Acoustics and Price ...... - 32 -

e) Reusability, Low wastage and building code adaptable ...... - 33 -

f) Better Coordination through improved communication ...... - 33 -

1.5 Limitation of modular construction ...... - 34 -

a) Design & Transport Constraints ...... - 34 -

b) Resale value ...... - 34 -

c) Local and General Land Restrictions ...... - 34 -

2. Background...... - 37 -

2.1 Objective and methodology of the study ...... - 37 -

2.2 Background of SEMODU AG ...... - 38 -

2.3 Why Hybrid? ...... - 38 -

3. Case studies ...... - 47 -

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3.1 461 Dean Rental Apartments, New York, USA. (Mixed Use) ...... - 47 -

3.2 Carmel Palace, New York, USA. (Residential Apartments) ...... - 53 -

3.3 Cube 11, Ludwigsburg, Germany (Residential Apartment) ...... - 57 -

3.4 Alho Modular Buildings, Germany (Systembau Modular Building)...... - 62 -

4. Design ...... - 70 -

4.1 Concept ...... - 70 -

4.2 Floor Plans...... - 72 -

4.3 Façade Elevational View ...... - 76 -

4.4 Perspective Views ...... - 77 -

4.5 Stacking connectors ...... - 78 -

5. Project Scheduling Comparison ...... - 81 -

5.1 In-situ method chart ...... - 82 -

5.2 Modular method chart ...... - 84 -

5.3 Results ...... - 85 -

6. Cost Comparison ...... - 87 -

6.1 In-situ method ...... - 87 -

6.2 Modular method ...... - 90 -

6.3 6C cost-approach ...... - 91 -

6.4 Results ...... - 92 -

7. Conclusion ...... - 93 -

Declaration of Authorship ...... - 95 -

List of Literature ...... - 96 -

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Table of Figures

Figure 1: Conventional Vs Modular timeline ...... - 12 - Figure 2: Housing demand in major German cities...... - 13 - Figure 3: All round benefits of modular construction...... - 14 - Figure 4 : Crystal Palace from Britain’s Great Exhibition ...... - 15 - Figure 5 : Graphical representation and image of Moshe Safdie’s Habitat 67, Montreal ...... - 16 - Figure 6 : View and Pod detail of Nakagin Capsule Tower, Tokyo ...... - 18 - Figure 7: View and details of Ramot Polin, Jerusalem ...... - 19 - Figure 8: View and details of Oriental Masonic Gardens, New Haven, USA ...... - 20 - Figure 9: Layout in 3D imagery and view of a BoKlok house ...... - 21 - Figure 10 View, fabrication and details of 461 Dean, Brooklyn, New York ...... - 22 - Figure 11 View of LOT-EK container building ...... - 22 - Figure 12 A typical WBS 70 Plattenbau detail ...... - 24 - Figure 13 IW 65 Magdeburg(left) and IW 64 Brandenburg (right) details...... - 25 - Figure 14 M10 Magdeburg view ...... - 26 - Figure 15 P2 type building view ...... - 26 - Figure 16 Nuebrandenberg housing complex ...... - 27 - Figure 17 Doppelsegment staße near Berlin Ostbahnhof ...... - 27 - Figure 18: Kieran Timberlake - Steel and Wood Modular Housing...... - 28 - Figure 19: Kieran Timberlake – Completed Module on Site ...... - 29 - Figure 20: Precast module being casted on site...... - 30 - Figure 21: Precast module being casted on site...... - 32 - Figure 22: Modular Construction - Marriott Hotel in New-York ...... - 35 - Figure 23: Modular Construction - Marriott Hotel in New-York ...... - 35 - Figure 24 Cost comparison ...... - 42 - Figure 25: Modular Construction – Scale of the structure in Pacific park neighbourhood ...... - 47 - Figure 26: Data Driven Tetris Approach ...... - 48 - Figure 27: Isometric View Typical Module detail ...... - 49 - Figure 28: Unity Typology ...... - 50 - Figure 29: Module manufacturing in Navy Yard ...... - 51 - Figure 30: Corner Windows from Base - Lintel ...... - 52 -

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Figure 31: The compact modular concept in Kips Bay ...... - 53 - Figure 32: The compact modular concept in Kips Bay ...... - 54 - Figure 33: Transformable Unit’s (Shrink Planning Strategy) ...... - 55 - Figure 34: Unit Types and Plans ...... - 55 - Figure 35: Module at Brooklyn-Navy Yards ...... - 56 - Figure 36: Holzbau Cube 11 ...... - 57 - Figure 37: 11 x 11 Cube Module ...... - 58 - Figure 38: Unit Concept, Cube 11 ...... - 59 - Figure 39: Floor Plant Type 1 ...... - 59 - Figure 40: Floor Plan Type 2 ...... - 60 - Figure 41: Façade with Panels, Battens and Plain Finishes ...... - 61 - Figure 42: Floor Plan Typology 1 ...... - 62 - Figure 43: Floor Plan Typology 2 ...... - 63 - Figure 44: Typologies Alho Modular ...... - 64 - Figure 45: Punk Hauser - Block Apartments...... - 65 - Figure 46: Floor Plan 2zw apartment details ...... - 66 - Figure 47: The Finishes of the apartment ...... - 66 - Figure 48: Zeilen Bebauung Apartment Block (Design Variable Organic Form) ... - 67 - Figure 49: Planning for Alho Modular Housing ...... - 68 - Figure 50: Module Configuration (Author’s work) ...... - 71 - Figure 51: Ground Floor Plan (Author’s work) ...... - 72 - Figure 52: Typical Floor Plan (Author’s work) ...... - 73 - Figure 53: Terrace Floor Plan (Author’s work) ...... - 74 - Figure 54: View 03 (Author’s work) ...... - 76 - Figure 55: View 04 (Author’s work) ...... - 76 - Figure 56: View 01 (Author’s work) ...... - 77 - Figure 57: View 02 (Author’s work) ...... - 77 - Figure 58: Post tensioned modular system...... - 78 - Figure 59: Corner cast used in SH Modulbau ...... - 79 - Figure 60: Detail of corner cast arrangement ...... - 80 - Figure 61: Gantt chart in In-situ method, Part 01(Author’s work- Refer Appendices) .. - 83 - Figure 62: Gantt chart in In-situ method, Part 02(Author’s work- Refer Appendices) .. - 83 -

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Figure 63: Gantt chart in modular method, Part 01(Author’s work- Refer Appendices) - 84 - Figure 64: Gantt chart in modular method, Part 02(Author’s work- Refer Appendices) - 85 - Figure 65: Schedule graphical comparison (Author’s work)...... - 85 - Figure 66: Simplified schedule – Modular construction ...... - 86 - Figure 68: 6C Cost Approach (Author’s work) ...... - 92 - Figure 69: Cost graphical comparison (Author’s work) ...... - 92 -

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List of Tabulations

Table 1: Market penetration of modular construction in detached homes ...... - 23 - Table 2 : CO2 emission and energy comparison between various building materials . - 39 - Table 3: Structural Considerations (Author’s work) ...... - 87 - Table 4: Cost calculation in In-situ method (Author’s work) ...... - 89 - Table 5: Cost assessment in modular method (Author’s work) ...... - 90 -

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List of Abbreviations

Fig. Figure

WWII World War 2

US/USA United States

WECD World Commission on Environment and Development

MEP Mechanical Electrical Plumbing

HVAC Heating Ventilation and Air Conditioning

GDR The German Democratic Republic

DFMA Design for Manufacture and Assembly

PPVC Prefabricated Prefinished Volumetric Construction

RCC Reinforced Cement Concrete

CLT Cross laminated timber

CO2 Carbon dioxide

LEED Leadership in Energy and Environmental Design

NYC New York City

DGNB Deutsche Gesellschaft für Nachhaltiges Bauen(The German Sustainable Building Council)

GFA Gross floor Area

WBS Work breakdown structure

BKI Baukosteninformation(Construction cost information)

DIN Deutschen Instituts für Normung

BIM Building Information Modeling

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Introduction

1.1 Definition and Brief

The terms Prefabrication and Modular construction are often used in close coordination. Prefabrication is a process of structurally designing and producing elements of building construction off-site. These can range from units of wall, floor, beams to more complicated elements like staircase and facade systems. While Modular construction is a process of off-site production and on-site assembling of prefabricated module units which are self-enclosing dwelling spaces. They can range as per project requirements and designer’s vision, starting from entire capsule apartments to individual room units.1

What is Modular Construction?

Modular construction is a process in which a building is constructed off-site and is assembled on-site. Off-site construction of building is done under controlled conditions, using the same materials and designing to the same codes and standards as conventionally built buildings.2 Buildings are produced in “modules”, involving process of planning, designing, fabricating, transporting and assembling building modules.

Figure 1: Conventional Vs Modular timeline .3

1 (Wagner, 2016) 2 (WSP, n.d.) 3 (DW COM, n.d.) - 12 -

Once assembled on site, these buildings are virtually indistinguishable from buildings built conventionally on-site. And reflect the identical design intent and specifications of the most sophisticated on site-built buildings without any compromise on aesthetics, quality and performance.4 One of the main reasons for using modular construction is to speed up the delivery time as compared to traditional on-site construction.

Supply-Demand Ratio

Berlin, Cologne and Munich being the major cities in Germany have an acute shortage of housings. As per the Handelsblatt report these cities need 1.9 million more home. The German government has promised 100,000 flats for low-income earners, investing 5 million euros.5

Figure 2: Housing demand in major German cities.6 To overcome shortages in housing supply, building industry needs to consider new and innovative forms of construction. There is an urgent need to switch to modern methods of construction that are high in quality, fast to deliver and are environment friendly and sustainable.7 With strong demand for affordable housing, modular

4 (Institute, n.d.) 5 (Williams, 2018) 6 (Wilson, 2018) 7 (Williams, 2018) - 13 - construction seems to have gained traction in building industry.8 Need of modular construction is driven by extreme shortfalls in supply of affordable housing and labor crunch in the conventional construction industry, that is making it hard to secure services, increases their cost, compromise quality and draw out build schedules resulting in delay in supply of good quality affordable housing.9

Modular construction is seen as one of the most innovative method of construction that speeds up productivity and efficiency and can be built much faster than conventional construction in housing.10 On a conventional construction site, work starts with the sub- structure i.e. foundation and then super structure (i.e. start building ground, first, second floor and so on). With modular construction, work on both activates (i.e. sub-structure & super-structure) can start at the same time.11 Super-structure building blocks can be constructed off-site while sub-structure foundation work in on-going at site. Work on site then becomes solely a process of assembly pre-fabricated super structure blocks to create desired floor volume.12

Figure 3: All round benefits of modular construction.13

8 (Williams, 2018) 9 (Williams, 2018) 10 (Institute, n.d.) 11 (WSP, n.d.) 12 (WSP, n.d.) 13 (Krug, 2013) - 14 -

1.2 History of modular construction

With the growing need of fast paced construction, countries are transforming their conventional construction techniques to modular construction methods. This looks like a modern change, but modular construction has been around in the construction sector from as early as beginning of 19th century.

To begin with in the year 1830, an English carpenter named John Manning made and transported a wooden prefabricated house to his son in Australia. This approach got a mass usage a decade later to withstand the urgent housing requirement for California Gold Rush. Subsequently Crystal Palace of Britain’s Great Exhibition in 1851, built in matter of months was a modular construction using range of building materials like glass, timber and steel. Later in first half of 19th century a US based company named Sears Roebuck and Co sold nearly half million prefabricated residential units.14 While the first completely modular house was realized as late as 1933 by Robert W. McLaugh for Winslow Ames House. The house was made up of modular rooms with central core comprising of amenities like toilets, kitchen and essential building services.15

Figure 4 : Crystal Palace from Britain’s Great Exhibition16

14 (Deluxe modular, 2019) 15 (Wagner, 2016) 16 (Deluxe modular, 2019) - 15 -

WWII (World War 2) period and post reconstruction phase saw a massive rise in demand for modular construction in US, Europe and Japan. (Deluxe modular, 2019) One of such example is prefabricated bathroom modules made by Buckminster Fuller which was send from US to Europe to be used by the battalions during the war period. In the year 1942, the town of Oak Ridge was to be built by the government of US for varied sizes of families. The requirement was a quick construction time frame and a construction technique that promotes flexibility. Skidmore, Owings & Merrill delivered this task in assembly units made up of cemento, a sugarcane base panel material.17

Habitat 67, Montreal (1967):

Israeli Canadian Architect Moshe Safdie during his thesis project “A Case for living City” envisioned a solution to meet with challenges of rapid urbanisation. He wanted to abandon the prevalent orthogonal high rises design trends and give end users a cheaper and sub-urban garden home lifestyle while still being in the city. His thesis project work was on a master plan scale, comprising of a mix-use approach, having shopping complexes, schools and 1000 dwelling units complementing each other. The work was chosen for World Exposition 1967, but the scale was reduced to mere 158 dwelling units by the Canadian government. 18

Figure 5 : Graphical representation19 and image20 of Moshe Safdie’s Habitat 67, Montreal

17 (Wagner, 2016) 18 (Merin, www.archdaily.com, 2013) 19 (pinterest, n.d.) 20 (Wagner, 2016) - 16 -

The project was inspired by Brutalism and Metabolism Architectural movements. It was constructed in Cite du Havre, a man-made peninsula of Montreal using 354 concrete modular blocks(boxes) individually weighing 90 tonnes and having an area of around 60 SqM each. 15 types of apartments were designed out from one to four modular blocks and comprised areas of 60 to 160 SqM. The modular blocks were prefabricated on the site area and thereafter equipped with MEP-HVAC fittings, kitchen finishing and toilet finishing, before being lifted and put in the building position. These blocks (having dimensions of 11,58m X 5,18M) were arranged and stacked in an offset manner so that each block gets ample natural light and large open terraces to be used for horti- culture. The 12-storey apartment is reached using three vertical cores and pedestrian pathways and bridges. Though initially being conceived just for the purpose of exhibition, the novel idea proved successful and the building was retained thereafter. Later, many building designs got inspired by Habitat 67.21 22

Nakagin Capsule Tower, Tokyo (1972):

In 1972, Architect Kisho Kurukawa envisioned an apartment out of small modular units (called pods or capsule units) in the expensive and highly commercial Ginza district (translates to silver district) of Tokyo, Japan. This apartment was meant to serve the travelling businessmen in the city during the weekdays. After construction apartments were bought by companies, artists and service individuals. It served both as studio apartments for individuals and as temporary guest house/hotel for companies. The Architectural style was inspired by metabolism and mega structure movement of 1960s which focuses on parameters of sustainability, reusability, flexibility, dynamism and in- terchangeability. 23 24

21 (Merin, www.archdaily.com, 2013) 22 (Habitat 67, 2018) 23 (Nagakin Capsule Tower, n.d.) 24 (Sveiven, 2011) - 17 -

Figure 6 : View and Pod detail of Nakagin Capsule Tower, Tokyo25

The 14-storey high apartment block consisted of 140 capsule units of 8 different types plugged to the central core at various angles using 4 high tension bolts. These capsules were designed and stacked as such that it can be replaced if required in future. These capsules could be inter-connected for larger functional usage. The 4m X 2.5m capsule unit was designed to satisfy the requirements of a single person. These units were prefabricated in a factory called Shiga Prefecture. The interior was pre-installed with circular window, bed, toilet, television, radio, mini kitchenette, reading corner, etc. This furnished unit was transported using trucks and then was lifted by mechanical crane to be plugged into the designated place. For material, steel frames and precast concrete was used in the core area. While capsules were fabricated in steel covered with galvanised steel panels of size 1m X 2m X 3m. For fire prevention all structural and exterior elements were coated with 30mm to 45 mm of asbestos spray. 26 27

Ramot Polin, Jerusalem (1977):

The Ramot Polin neighbourhood comprises a built-up area of 72000 SqM. It was designed by Polish Israeli Architect Zvi Hecker. This compound was built after Six-day Israeli war, when the government of Israel wanted to populate the newly occupied ter- ritory on a lone hill close to Jerusalem. The building has a beehive form and is regarded

25 (Sveiven, 2011) 26 (Nagakin Capsule Tower, n.d.) 27 (Sveiven, 2011) - 18 - as one of the sample buildings with Architectural experiment on morphology. The building form has been modified by the dwellers as per their requirement in the absence of a strict building regulation in the area. 28 29

Figure 7: View and details of Ramot Polin, Jerusalem30

The building is made up of over 700 dodecahedrons shaped modular concrete blocks (form with 12 pentagonal faces). This dodecahedron has been interlocked to form an organic beehive type morphology. The shape was conceived to stand out amidst the

28 (Grozdanic, 2013) 29 (Merin, AD Classics: Ramot Polin / Zvi Hecke, 2013) 30 (Grozdanic, 2013) - 19 - monotonous surroundings and promote sustainable construction through pre-fabrication. The neighbourhood consisted of apartments, parking spaces, shopping area, school and community services. The apartment consists of four bedrooms each that are regular in form. The pentagonal corners are utilized for washrooms, kitchens and terraces. This radical experiment by the Architect has proved to be a failure, especially after the organic interventions by the occupants. 31 32

Oriental Masonic Gardens, New Haven, USA (1970):

This project was financed by the federal government to meet the growing housing needs city of New Haven in 1970. The project was designed by Architect Paul Rudolph in area spanning 12.5 acres. The compound housed 148 apartments (2 to 5-bedroom units) made from 333 modular blocks. The neighbourhood was termed as a failure and demolished in 1981 to make way for new housing complex called Westfield Manor.33

Figure 8: View and details of Oriental Masonic Gardens, New Haven, USA34

Each apartment unit consisted of two modular blocks, one at ground floor which housed common spaces and other suspended on first floor which houses bedrooms.

31 (Grozdanic, 2013) 32 (Merin, AD Classics: Ramot Polin / Zvi Hecke, 2013) 33 (PAUL RUDOLPH HERITAGE FOUNDATION, n.d.) 34 (PAUL RUDOLPH HERITAGE FOUNDATION, n.d.) - 20 -

Four of such apartment units were connected to the central core. Each unit had its own private garden independent facing outwards. The roof was vaulted in form using double layer of plywood. 35

Recent attempts:

IKEA and Skanska collaborated to deliver low cost houses to Scandinavians called BoKlok houses in 1996. It failed to create a market flutter due to low quality design and over standardization. Lately designs have been improved and the market has been extended to serve major economies like UK and Germany. 36

Figure 9: Layout in 3D imagery and view of a BoKlok house37

While in 2003, LOT-EK launched mobile dwelling units made of connected shipping container. But following projects have proved to be a success in recent times in the category of prefabricated construction with respect to time of construction, scale of construction and budget of construction: a) 57-story Ark Hotel in Changsha, China (2010) - Built in 19 days b) 461 Dean, Brooklyn, New York (2016) - World's tallest modular building

35 (Rudolph, 1970) 36 (Video, 2019) 37 (BOKLOK – prefabricated homes from IKEA, n.d.) - 21 - c) 500-bed hospital in Calicut, India (2017) - BIM supported and 1⁄4th cost of US hos- pitals.38

Figure 10 View, fabrication and details of 461 Dean, Brooklyn, New York 39 40

Figure 11 View of LOT-EK container building41

38 (Video, 2019) 39 (Elena, 2016) 40 (Budds, 2016) 41 (Belogolovsky, 2018) - 22 -

Following is the market penetration of modular construction in detached homes:42

Country Percentage

Sweden 84

US 05

Germany 09

Netherlands 20

Japan 28

Table 1: Market penetration of modular construction in detached homes

42 (Deluxe modular, 2019) - 23 -

1.3 History of modular construction in Germany

GDR built around 2,17 million dwelling units with Plattenbau construction between 1958 and 1990. 43 The demand of social housing increased after the second world war due to mass destruction of cities and displacement of population. The Soviet Union and its controlled territories such as GDR used modular construction to com- bat this crisis. This was inspired by similar housing methods already prevalent in Netherlands and USA. The social housing method focused on prefabricated construction of foundation, staircase, slab, beams and walls. Due to its minimalistic design and modular scheme, it was quite cheap for the masses. It had a repetitive design and usually were 5 storeys high to avoid the requirement of vertical lifts thereby reducing considerable cost of the building. It was quite in demand during that era because it had modern features of the time such as central heating, running water, private bathrooms, kindergartens, schools and park spaces. There was long waiting list to get this apartment. After the unification of Germany, these buildings lost its glory. But lately they are being now refurbished functionally and aesthetically to meet the demand of present generation.44

Figure 12 A typical WBS 70 Plattenbau detail45

43 (Verlag, 1996) 44 (Stay, 2017) 45 (BBSR, 2014) - 24 -

Plattenbau buildings can be described briefly into these types:

a) IW 65 Magdeburg

These buildings were basically strip version of the larger panel-based construction that followed up in coming years. The limitation arises due to capacity of crane lifting which was only 0.8 tonnes. The building height varied from 4 to 5 storeys. The first project with this series was Jena-Neulobeda in 1966.46

Figure 13 IW 65 Magdeburg(left) and IW 64 Brandenburg (right) details.47

b) M10 Magdeburg

Year of construction: 1973 to 1981 Approx. apartments: 11000 Height: 10 floors mostly Width: up to 20m These apartments use larger panel sizes and had prominent windows. The balconies were replaced by loggia. Different permutation of sizes and flat type ex- isted in the same building.

46 (Jeder M2 DU Das Plattenportal, kein Datum) 47 (Jeder M2 DU Das Plattenportal, kein Datum) - 25 -

Figure 14 M10 Magdeburg view48 c) P2

P2 was one of the most common series of Plattenbau. It was a pioneer in rede- fining living by introduction of open floor plans. It had no load nearing partition walls. It proved to be economical, lean construction and supported living comfort. This building design was chosen by Bauakademie after creating 15 sample apartments. This type was later replicated with success in Berlin and Frankfurt. The staircase, toilets and kitchens were centralized leaving all rooms with ample light and ventilation. Large windows were a resulting characteristic.

Figure 15 P2 type building view49

48 (Jeder M2 DU Das Plattenportal, kein Datum) 49 (Jeder M2 DU Das Plattenportal, kein Datum) - 26 -

d) WBS 70

This was another most common series pf prefabricated building od GDR era since 1970. It was based on a slab grid of 1.2 m X 1.2m. This was made more cost effective in comparison to its predecessor P2 type buildings. From 1972 to 1990, the number of such apartment is recorded to be 644,900. One of the first such apartments were Neubrandenberg housing complex.

Figure 16 Nuebrandenberg housing complex50

e) WHH-GT 18/21 It had a footprint of 35.34m X 18.84m. It mostly had 18 floors but in some cases 21 floors too. Ground floor usually comprised of utilities such as restaurants and shops. Depending on its varied version one building could house from 136 to 296 apartment units.

Figure 17 Doppelsegment staße near Berlin Ostbahnhof51

50 (Jeder M2 DU Das Plattenportal, kein Datum) 51 (Jeder M2 DU Das Plattenportal, kein Datum) - 27 -

1.4 Benefits of modular construction:

Considering the wide adoption of modular construction over decades in the AEC industry; a lot of research and development has undergone in developing prototype modules. A system could be unitary, or hybrid designed and processed as per manufacturing requirements. The market scenario suggests permutations and combi- nations of hybrid material composites that are widely explored within the industry to adapt to the demands of clients and be ahead in the competition. The following chapter summaries them.

a) Time Saving

Construction of modular buildings can occur simultaneously with the site and foundation work, allowing projects to be completed in much lesser time compared to traditional construction. Most of the construction work is completed inside a factory, thus mitigating the risk delays due to adverse weather conditions. Buildings are occupied sooner, creating a faster return on investment.52 It is possible to build a small modular house at the factory in less than two months. The reason for this is optimization, increased repeatability and teamwork. The built-up time is a crucial factor in modular housing. One such example is from architect Kieran Timberlake architects housing project completed in 2009. The 2500 square feet two storey high house was built in less than 4 months.53

Figure 18: Kieran Timberlake - Steel and Wood Modular Housing.54

52 (Koutsogiannis, 2018) 53 (Timberlake, 2019) 54 (Chino, 2009) - 28 -

Figure 19: Kieran Timberlake – Completed Module on Site55

This example of construction elucidates that modular construction can be completed in less than standard year time span. Recent developments in technology has put down the time more to less than 8 days. One such example Is DFMA which is the future of construction industry.56

55 (Chino, 2009) 56 (O'Rourke, 2013) - 29 -

b) Offsite Construction & Flexibility

DFMA is a popular method adopted for construction which requires a strong supply chain mechanism. The mechanism uses both the manufacturing part and assembling part in order to achieve higher durability for any modular prototypes. One of the key elements for the module is to make up a connecting element sturdier than those assembled offsite.57 Also the pre-assembled houses need to meet plan pre- requisites, yet in addition withstand transport loads.

Figure 20: Precast module being casted on site.58

Laing Rourke, one of the leading DFMA manufacturer has proven that commer cial structures can also be transported in shortest time along with its usability for commercial purposes. The Dagenham Park Church of England School built in 2012 is

57 (Aurisicchio, 2017) 58 (Concrete Magzine, 2019) - 30 -

an excellent example of offsite construction completed. The structure was built in 70% less time as compared to standard benchmark of in-situ construction.59

In terms of flexibility, modular buildings can be customized to fit with exact space requirement, design specification and budget requirements.60

c) Quality, Damage & Risk

The production line techniques used in the modular construction enable quality control management systems to be applied and adhered to, following best practice requirements. All modules undergo thorough testing and inspections to ensure good quality. Efficient sequencing of work and fewer conflicts in scheduling during production contributes to less rework or deficiencies.61

The Scandinavian and Russian market is way ahead in terms of implementation of design and manufacturing modular housing since they are doing it since the world war I time period. Elematic oy group from Finland are experts in precast. Wall and Floor components are key elements for this type of construction.62

The key questions addressed by the research and manufacturing group are making damage proof panels which can be placed directly on site. Considering climatic conditions certain composites are added according to the context of construction. One such example Is from Finland where the thermal resistance capacity is considered for composite material manufacturing thus by reducing the risk in post oc- cupancy.63 Modular construction increases safety and security of man and ma- chine. Controlled factory environment reduces the risks of accidents and related liabilities for workers.64

59 (O'Rourke, 2013) 60 (Koutsogiannis, 2018) 61 (Wilson, 2018) 62 (Juvas, 2004) 63 (Pankoke, 2008) 64 (Wilson, 2018) - 31 -

Figure 21: Precast module being casted on site.65

d) Acoustics and Price

Acoustics play a major role since modular floors come with gaps which result in better insulation of noise. The price factor is affordable since the design costs are already catered before. Hence the customer receives the finished product. To- gether these factors constitute to contractors benefits since one must deliver an almost ready module on site.66 Light steel frames help in absorbing the vibration loads by wooden fillers.67

Economies of scale of material stock, standardization, and modularization are key to achieve cost reductions Cost saving also comes from labour cost on-site labor which are less specialized and more efficient in a production line setting.68 Cost saving due to reduction in material wastage due to weather related delay and damage. Integrated processes involved in modular construction remove the need for sub-contractors and therefore reduces related costs.69

65 (Elematic , 2019) 66 (Chino, 2009) 67 (Steel, n.d.) 68 (Institute, n.d.) 69 (Williams, 2018) - 32 -

e) Reusability, Low wastage and building code adaptable

Modular buildings can also be dis-assembled, re-located or re-furbished for new purpose. This helps reduces demand of raw material, energy required to create a new building.70 Factory controlled process generates less waste; waste is elimi- nated by recycling materials, controlling inventory and protecting building materials from adverse weather conditions.71 Modular buildings are built to meet or exceed the same building codes and standards as conventional on-site structures.72

f) Better Coordination through improved communication

Conventional construction faces many hurdles including poor coordination and poor communication being, partly because there are different teams handling different construction stages. In case of modular construction, the various teams involved in construction work come together at one central location (i.e. factory/ manufacturing unit). This way, communications and coordination improves at all levels and en- sures that information is exchanged in a timely and efficient manner.73

Additionally, Greater degree of cost control reduced carbon emissions due to transportation to and from site associated with on-site construction, less site disturb- ance.74

70 (DW COM, n.d.) 71 (Koutsogiannis, 2018) 72 (Wilson, 2018) 73 (AECOM, n.d.) 74 (AECOM, n.d.) - 33 -

1.5 Limitation of modular construction

As of the advantages the disadvantages come with constraints and technical problems. The author has summarised them as follows.

a) Design & Transport Constraints

Depending on the construction materials and construction type lifecycle of a module can be evaluated. For example, paints and finishes used on the outer side of the wall can vary the cost and durability along with interior finishes. From design constraints the module could be very small and cannot be altered post the production phase since they get heavy and difficult to transport.75

b) Resale value

Although the market value here is high the resale value of such housing is very low since the assumption of such typology is perceived to be low quality. However, the notion of the same is changing since the typology is being heavily adopted in commercial construction too.76

c) Local and General Land Restrictions

One of the major constraints is where the modular unit is going to be placed. De- pending on the country and local laws these built ups are highly affected. Some regulatory authorities may charge heavy for these type of construction in terms of taxation while some may not.77 Many countries are showing interest towards offsite construction in Europe while the adoption in developing countries could be more after piloting the projects. Overall in comparison the advantages rise to a maximum looking at the technological and transportation aspect.78

75 (Yi Yang, 2017) 76 (Rippon, 2011) 77 (Chino, 2009) 78 (Nick Bertram, 2019) - 34 -

Figure 22: Modular Construction - Marriott Hotel in New-York79

Figure 23: Modular Construction - Marriott Hotel in New-York80

79 (Brenner, 2019) 80 (Brenner, 2019) - 35 -

The latest announcement on Marriott hotel chains producing the tallest modular hotel indicates to these developments in this sector. BIM has been implemented in the project for efficient design. The designers claim that it has allowed them to in- crease the construction speed by 25%.81

To sum up the overall construction industry is looking forward to improvised solu- tions of modular construction which are fast and easy to transport and cost effective to build. The aim is to design a modular prototype for SEMODU AG. Hence a further enquiry for modular construction players in the German market needs to be considered. The following shall be discussed in the case studies below.

81 (Brenner, 2019) - 36 -

2. Background

2.1 Objective and methodology of the study

Objective: Design optimization and cost estimation of hybrid building modules in AEC (Architecture, Engineering, Construction) industry.

Methodology: In this thesis SEMODU's concept is studied and analysed. Its illustra- tions are compared in detail with historic and contemporary works in the modular construction sector. Similar European projects or/and literature works is taken up as case studies and its pros & cons is ascertained. Various building materials are studied in this work and suitable hybrid combination of RCC (core) and wood(shell) is established. For construction phase, SEMODU works in association with Max Bögl Group. Existing module sizes of Max Bögl Group and other precast module fabricators is taken into consideration for compatibility arrangements. The author came up with a design proposal for such a modular-hybrid concept in the area of residential real-estate development. Cost assessment of the design and its comparison with the conventional construction is done. Difference in the construction time between the two models, will also be examined.

Research questions:

a) What is the strength, weakness, opportunity and threats of the PPVC concept in AEC sector? b) What is the percentage of cost saved by this concept? c) What is the percentage of time saved by this concept?

Expected results:

a) A detailed design complimenting the SEMODU's concept. b) Cost estimation of the concept. c) Cost comparison with the conventional method of construction. d) Construction time comparison with the conventional method.

- 37 -

2.2 Background of SEMODU AG

This Master thesis is being done in collaboration with SEMODU AG(Munich). SE- MODU envisions a futuristic modular-hybrid construction concept that aims at reducing construction time and construction cost. The concept consists of concrete core and timber shell building structure in a modular form. It aims at using advantages of both concrete and timber simultaneously. The focus also extends to increasing construction efficiency, customer flexibility and meeting carbon neutrality goals. This can be utilized in small- or large-scale constructions, residential or commercial real estate constructions and high end or affordable housing constructions. This thesis work aims at ana- lysing the concept and coming up with a design proposal for the same in area of residential real-estate development. Technical details and cost estimation will be provided by the author.

2.3 Why Hybrid?

In this section, author will elaborate on advantages and disadvantages of three types of construction materials namely wood, steel and concrete. From this necessity of hybrid construction will be derived and established.

Wood: Timber or wood is one of the most historic building materials of human exist- ence. Due to its varied properties and flexibility, it was for building construction for thousands of years. With onset of steel and concrete post industrialisation, wood lost its glory. But it remained desirable for high end, rural and classic construction technique enthusiasts. In recent times, timber is making quick gains in the construction sector due to its upgradations such as CLT (cross laminated timber).

Advantages:

a) Wood is resistant to electricity and heat. This provides a safe building to the users and low energy bill due to low heat/cold loss. It is also having a good sound absorbing properties.82

82 (Carigliano, 2019) - 38 -

b) It is light weight and has high tensile strength. Large spans can be designed without giving numerous vertical supports.83

c) The material can be reused even after many years. It is flexible and can be totally brought to a new usage or even put into minor changes.

d) This material can be locally sourced by planned growth and processing. It is environmental benefits are well known. It decomposes easily in nature, whether we talk about the construction waste or complete disposal. According to a study, CO2 emission and energy required for one square meter of floor space in construction are as follows:

Material Co2 emission (in Kg) Energy (in megajoules) Wood 04 80 Concrete 27 290 Steel 40 516

Table 2 : CO2 emission and energy comparison between various building materials84

e) While another research suggests that life cycle carbon emission of wooden buildings is 69% and 74% less than concrete and steel buildings respectively.85

f) It is cheaper building material and has less maintenance cost over its life cycle. Although the volume of material is more per square meter of floor space. 86

g) Culturally and historically people are used to living in wood houses. Continua- tion of the same is associated with pride in some cultures. So, its social value cannot be ignored.87

83 (Carigliano, 2019) 84 (Cao, 2019) 85 (Cao, 2019) 86 (Barekat, Han, Dewan, & Qian, 2010) 87 (Barekat, Han, Dewan, & Qian, 2010) - 39 -

h) Its construction efficiency cannot be ignored. It reduces the total construction time and its carpentry is mostly independent of the weather patterns at the site. The foundation for a wooden house is designed to carry quite low load because of the lightweight construction. This reduces cost, carbon emission and energy consumption for construction. 88

Disadvantages:

a) Wood house is prone to deterioration if not taken affirmative measures and care in its project life cycle. Especially in wet areas, such as kitchen and toilet, the water-resistant environment needs to be guaranteed. Over exposure to water can cause unrepairable decay.

b) Biotic decay: This is caused by fungi, bacteria, mould, insects infesting the wooden surface and slowly eating it up to make it weak. This spreads rapidly if not attended in time. Special chemical treatment is required in affected buildings.89

c) Abiotic decay: This is caused by unprotected exposure to water, wind, sun, chemicals and heat over a period. The nature can eat up this building material in extreme weather conditions. Shrinkage or swelling of wood are some of the visible decays.90

d) Although wood takes longer to lose tensile strength in case of fire, but it is highly flammable in property to catch the fire in first place.91

Structural Steel: Steel has one of the most successful building materials in the recent history of Architecture, Engineering and construction. It owes to the erection of many

88 (Barekat, Han, Dewan, & Qian, 2010) 89 (Carigliano, 2019) 90 (Carigliano, 2019) 91 (Barekat, Han, Dewan, & Qian, 2010) - 40 - high-rise buildings especially so in US. To make steel, iron ore is extracted from the earth. It is then melted in high temperature and mixed with metals such as chromium, nickel and carbon extracts to get desired chemical properties for example brittleness, tensile strength, etc. It is by far the strongest building material. Most heavy structures such as bridges, railways, etc are designed in steel historically.92

Advantages:

a) Steel is not flammable, so it’s considered fire resistant. Although in contact with the flame over an extended period, it starts to transfer heat to the other parts of the building and lose its strength, and gradually buckle down. Due to its extended and predictable elastic nature it is safe for the users as it is devoid of sudden failure. Steel is flexible, due to which it doesn’t break during earthquake and hence considered an earthquake friendly construction material. During the time of lightening, it transfers the electricity to the ground due to high conductivity, which results in no damage to building and its occupants.

b) Steel can be recycled and converted for different uses even after a century of use. Studies show, in North America about 69% of the steel is recycled every year.

c) Steel requires minimal maintenance once the structure is erected. It is immune to biotic decay such as fungi, bacteria, mould and insects. It can be immune to abiotic decay (water, wind and sun) as well, if attended well with regular care of painting and polishing of exposed surface.

d) The water used in its production is 95% reusable and the greenhouse gas emission in its production has seen 45% decline since 1975.

e) The members of steel building are prefabricated. That means a faster construction time as compared to the conventional RCC construction.

92 (Carigliano, 2019) - 41 -

f) Although steel is costly, but studies reveal that due to its high strength the quantity of material required for the same construction is less. As per the study, the difference in cost per square feet as compared to wood is only 8 $ higher. Fol- lowing chart depicts the analysis:

Figure 24 Cost comparison93

g) The other cost advantages are low building insurance premium and low transportation cost.

h) Socially speaking, steel results in large job production starting from mining, refining, production, transportation, assembly and construction. 94

Disadvantages:

a) Steel uses large amount of energy during its manufacturing process. This is estimated to be twice the energy required for manufacturing same weight of wood.

b) Steel´s conductivity is 310 times greater than that of wood. This makes it highly nonuser friendly in regions of extreme climate. To compensate this energy loss, the building requires lot of energy. This results in increased running cost of the building.

93 (Barekat, Han, Dewan, & Qian, 2010) 94 (Barekat, Han, Dewan, & Qian, 2010) - 42 -

c) Steel requires regular painting otherwise rusting can decrease the strength of the building material massively.95

d) Steel requires good fire protection because of its high conductivity. 96

Reinforced Concrete: RCC (Reinforced cement concrete) is a combination of steel bars and concrete. While concrete comprises of mixture of cement, sand and aggre- gate. This is the most common building material in the present era of modern and post- modern Architecture. Due to its local abundance and flexibility of use it has been adopted worldwide on small- and large-scale constructions.97

Advantages:

a) RCC has high compressive strength as well as adequate tensile strength due to the right combination of flexible steel and brittle concrete.

b) It is resistance to fire as the concrete cover provides natural shield to the steel reinforcement bars. So, during the fire dwelling user get more than ample time to escape from the building. The collapse of the RCC structure is not sudden in nature.

c) RCC provides great deal of flexibility to the Architect and designers because RCC can be moulded into any possible form unless the form is structurally un- stable. This is impossible to replicate in steel or wooden construction.

d) RCC is made up of low maintenance cost materials. If the steel is well protected during the lifecycle the concrete cover can be easily renovated. The construction of RCC buildings doesn’t require highly skilled labour.98

95 (Barekat, Han, Dewan, & Qian, 2010) 96 (Carigliano, 2019) 97 (Carigliano, 2019) 98 (Carigliano, 2019) - 43 -

e) Concrete is resistant to biotic and abiotic decay. It also supports good indoor air quality in the buildings. Although CO2 emission is high during construction phase, the life cycle of the concrete building is associated with low carbon emission and low heat/cool loss.

f) RCC is structures are more sound resistant than wooden and steel buildings.99

Disadvantages:

a) RCC requires in situ construction. Formwork must be erected and removed for every structure. This is time taking, expensive and labour intensive in nature.

b) Curing time of normal RCC structure ranges between 20-30 days. This is the time required by the structure to gain strength. This is more time consuming than steel or timber construction.100 Although this curing time can be reduced by using curing compounds in the concrete. It is more expensive but saves the overall construction time.

c) RCC must be placed into position in quick time before it starts setting. This demands quick, fast paced action on site. RCC leaves very less room for making changes once it sets down. Deconstruction and remodelling are not only expensive and difficult but also time consuming. Due to onsite fabrication, RCC construction results in substantive amount of waste on the site. This concrete waste is usually not recycled and amounts to waste dump lands.

d) When the RCC building is demolished, it results in large amount of dust in the air and concrete waste which is almost impossible to reuse. The separation of steel bars from the hardened concrete is cumbersome and expensive process. Although recent efforts have resulted in using these wastes in road construction projects.

99 (Barekat, Han, Dewan, & Qian, 2010) 100 (Carigliano, 2019) - 44 -

Hybrid Solution

Having studied the properties, advantages and disadvantages of steel, wood and RCC in detail, the author was in position to make an informed choice on the material(s) best suited for the project in prospect. Also, the local availability, climatic condition and manpower expertise was considered. Drawing inference from this study, the author intends to design the building using wood modular blocks with concrete (RCC) core carrying, staircase, lift and Mechanical, Electrical and Plumbing shafts.

Steel was found most unsuitable amongst the three choices. First due to its high thermal conductivity, it will require high amount of energy to keep building temperature conditions at an optimum level both in summer and winter. This is highly unsustainable in addition to the high amount of energy and carbon footprint steel leaves behind during extraction, refining and production. The iron ore is mostly imported from China, India and Africa. The lack of local abundance and huge transportation burden also makes it an unsustainable option. The sound insulation is also not the best when it comes to steel. In the history of modular construction, companies like of LOT-EK has made steel container office buildings and other hospital projects have been done using the same method. But when it comes to residential buildings, the user usually finds it not very comfortable and convincing to live in steel container buildings for long duration of time. Minimal amount of steel will be used in this project as part of RCC in the core module(s).

RCC is one of the most conventional methods of construction in this era. But due to the cast-in situ activity at the construction site the project requires a longer construction time. It is labour intensive in nature. Nevertheless, author intends to use the best qual- ities of concrete at the buildings advantage. Due to lower wear and tear, higher structural strength and right amount of flexibility it is ideal for designing building cores and foundation. Usually the pedestrian traffic is frequent in staircases, so RCC structure can withstand this constant traffic. Similarly lift is most suitable is RCC construction due to its strength and low conductivity. In case of fire, RCC core is most suitable to carry the users out from the building. As RCC is resistant to biotic and abiotic decay, it suits well to carry all the services shafts and vertical stacks. These shafts can carry mechanical, electrical, plumbing and firefighting stacks. The strength of RCC is also

- 45 - suited to withstand such loads. RCC will also provide better sound insulation from the core area (lift, staircase and plumbing pipe sounds) to the residential block users. In case of foundation too, concrete has been long the best solution owing to its high strength and low corrosion inside the soil’s surface.

For about 90% of the building construction author choses to go with the wood modular construction in CLT (cross laminated timber). This is high in strength and even being used for high rise wood buildings across the globe. The wood is locally available in Europe in abundance. Wood brings the old-world charm and glory. CLT can withstand against fire for much longer period as compared to ancient wood building techniques.

- 46 -

3. Case studies

3.1 461 Dean Rental Apartments, New York, USA. (Mixed Use)

Project Description – The tallest ever experimental modular apartment built in the New-York USA by world renowned architectural firm SHoP Architects. The apartments are classic example of volumetric modular construction. 101

Figure 25: Modular Construction – Scale of the structure in Pacific park neighbourhood102

The 363 rental block apartment is 32 storied with 36,210 Sqft of built up area pushing the limits of modular housing and scalability in the high-rise modular construction domain.103 A part of the Pacific park project in Brooklyn, New-York the typology found in the apartment is mixed use. The structure was built during a timeline of 2013 – 2016. The project is developed for affordable low- and middle-income households. Skanska and Arup were the two major contractors and consultants in project development and

101 (Architects, 2019) 102 (Database, 2019) 103 (Database, 2019) - 47 - construction management of the site.104 The total project costed 162.1 million dollars initially but later costed 195.6 million dollars due to disputes and time overrun.105

Key Highlights –

Technology, Material & Logistics - The material comprises of 930 steel modules and spans across a 4000 square feet of retail outlet area at the base. The type of modules used are full stack which pertain to the concept of “Tetris” as shown below in figure 8 developed by the full stack modular.106 The structure is a composite of steel and concrete.107

Figure 26: Data Driven Tetris Approach108

104 (Database, 2019) 105 (Older, 2016) 106 (Database, 2019) 107 (Database, 2019) 108 (Krulak, 2019) - 48 -

This type of technology helped in scaling, controlling and predicting the development rate of the construction process. It stands on top of data driven approach applied to develop the multi storey urban model for end user development.109 The methodology applied here are initial assessment, definitive programming, calculated design, swift analysis, optimised construction and accelerated assembly for higher production rate.110

Figure 27: Isometric View Typical Module detail111

109 (Krulak, 2019) 110 (Viktor, 2016) 111 (Database, 2019) - 49 -

Unit Planning - The apartment blocks offer different floor units in size due to site constraints and design for different units since the entire apartment is divided in 4 different parts.112 The design units have a differential nature due to split level planning. It was made in order to immediately fulfil the housing demands of New York. The real- estate rental companies in New York have the building highly in demand and is a major at- tractor for rental housing.113 The floor unit’s design and area data are described as below.114

Figure 28: Unity Typology 115

Each typology has viz. Studio – 7 types (419 –740 sq. Ft) One bedroom – 4 types (567–985 sq. Ft) Two Bedroom – 4 types (960 – 1086 sq. Ft). The entire complex has an amenity area which hosts a modern contemporary living standard. Due to multiple unit planning the criticality lied in pricing of these apartments.116

112 (Architects, 2019) 113 (Architects, 2019) 114 (Architects, 2019) 115 (cafe, 2019) 116 (cafe, 2019) - 50 -

Figure 29: Module manufacturing in Navy Yard117

Project Timeline and Pricing – The entire module was built 90% offsite at a factory located near the Brooklyn Navy Yard.118 The initial construction was delayed by two years due to stakeholders and contractors dispute. In the central area where the me- dian pricing was $2700 per month for one bedroom the developers offered variable pricing starting from studio costing - $559, one bedroom $600 and two bedroom $727 per month. However, the actual pricing later due to cost overruns had escalated thrice and are still not available in the public domain.119

A recent market rate rental analysis from Greystar and Curbed real estate property dealers show that the studio, one bedroom, two-bedroom pricing starts with $2450, $3125 and $4750 respectively.120 To summarise the case study learnings the following interrogatives were observed. Majority of the findings are from the design and

117 (Architects, 2019) 118 (Viktor, 2016) 119 (cafe, 2019) 120 (Warekar, 2016) - 51 - technology aspects and are generic in nature since the data available on the usage and aspects of it are not published yet.121

Positive Learnings - The approach to build such housing was indeed an experimental approach where the city skyline is low-rise in nature. Modular boxes are staggered smartly in a variable nature that a user when steps in cannot figure out the differences in joineries.122 From the design perspective having an angular opening and fully open window façade is now a proof of concept in modular domain as compared with traditional designs. The following can be seen below in the figure below.

Figure 30: Corner Windows from Base - Lintel123

Negative Learnings – The approach to build 960 modules library was highly challeng- ing. From developers’ perspective modular can be explosive design exercise if not taken care in the design stages of the project. The design defects comprising unit stacking for MEP led into cost overruns for two years.124 It would be made more compact as a lot of it is wasted in circulation. The pricing of modules is a grey area in nature

121 (Viktor, 2016) 122 (Architects, 2019) 123 (Viktor, 2016) 124 (Viktor, 2016) - 52 - due to cost escalations. Thus, how efficient and affordable high-rise modular construction is was a question at the end of the handover.125

3.2 Carmel Palace, New York, USA. (Residential Apartments)

Project Description – The apartment is an example of the first micro – living modular housing which was monitored by special regulations of the NYC city department housing officials. The housing happened to be the most experimental prototype winning entry for “aDAPT” design competition won by n-architects based in Brooklyn located at Kips Bay.126 The construction timeline was from 2013 – 2016. The project is LEED silver target as per the sustainability measures.127 The area of the target apartment is 35000 square feet constituting 55 micro unit apartments and retail area.128

Figure 31: The compact modular concept in Kips Bay129

125 (Database, 2019) 126 (Baan, 2019) 127 (Baan, 2019) 128 (Baan, 2019) 129 (Boom, 2019) - 53 -

Key Highlights –

The structure so called or conceived as “microsom” or “mini tower” is smartly managed in its marginal setbacks. The long 11-foot-wide and 9 storey high towers reflect the micro dimensionality of the apartments. The 4 – level vertical grey shade split helps in achieving the design directives.130 Picking the design principles from the old 19th century brownstones the 8’ tall windows are also placed add beauty into the interior spaces.131 Due to its popularity a total of 60,000 people enquired about the place. The planning scheme of the modules can be viewed from the west faced cut section as shown below in the figure below.

Figure 32: The compact modular concept in Kips Bay132

Price and Unit Planning and Types – The design is intended towards affordable housing, 22 out of 55 units are considered for the same which were sold at a lower

130 (Baan, 2019) 131 (Boom, 2019) 132 (Boom, 2019) - 54 - price. The 33 units were sold based on market rate out of which 14 were sold for a higher cap.133

Figure 33: Transformable Unit’s (Shrink Planning Strategy)134 The unit’s range between 260 Sqft to 360 Sqft. The 22 affordable housing apartments were sold at price of $950 to $1500.135

Figure 34: Unit Types and Plans136

133 (Boom, 2019) 134 (Cohen, 2016) 135 (Hurley & Volner, 2017) 136 (Hurley & Volner, 2017) - 55 -

Material and Design - The higher end range was sold from $2540 to $2910.137 The average unit price was $98 Sqft as compared to the standard market price which costed only $51 Sqft.138 8 units fit per floor and the entire site is 45’ x 108’.139 The modules were fabricated in Brooklyn Navy yard area. The 65 framed modules are made using steel as the main material. The total cost of the project was $12.95 million.140

Figure 35: Module at Brooklyn-Navy Yards141

Positive Learnings - The module design is based on a canvas toolbox concept.142 Looking at the design it is observed that small compact size with vertical stacking is possible in modular unit design. It can be highly customised according to the user and

137 (Hurley & Volner, 2017) 138 (Cohen, 2016) 139 (Hurley & Volner, 2017) 140 (Cohen, 2016) 141 (Hurley & Volner, 2017) 142 (Baan, 2019) - 56 - market needs depending on the developer’s requirement. The circulation is managed at edge while stacking the modules. Hence in any high-rise module-based construction it must be considered that the circulation must take minimum area.

Negative Learnings - The affordability in such kind of developments has always been a question in the American AEC community since the projects are experimental in nature.143 The unit modules always cost more than the expected price due to design measures which in turn have delays on project resulting in cost overruns. Overall it can be concluded that how affordable are these projects to the end users is always unclear.

The two case studies were done considering the popularity and technological aspect in the international markets for residential and retail use. Considering the research domain, the author has chosen wooden modular construction (Holz modular) as it is a popular concept in European countries.144

3.3 Cube 11, Ludwigsburg, Germany (Residential Apartment)

Project Description -

The project was a pilot project executed by Ludwigsburg Housing Association (WBL) for refugee housing. This was developed using prefabricated wooden modules on the concept of cube shape.145

Figure 36: Holzbau Cube 11146

143 (Greenspan, 2016) 144 (Nick Bertram, 2019) 145 (Ludwigsbrug, 2017) 146 (Ludwigsbrug, 2017) - 57 -

Key Highlights -

The design facilitates cost-effective living space which is eco-friendly and sustainable in nature. It was a part of “Living Lab Innovation Network” of the city accompanied by technical expertise from Technical University of Darmstadt. The project is affiliated to German sustainable council DGNB thus satisfying all the parameters of energy efficient buildings.147

Unit Planning -

After initial use by refuges the structure was retrofitted with balconies for further use and put on the rental market. The cube 11 concept comes from 11 x 11 meters of cube designed modules by Richter architekten bda along with WBL project management consultant company as shown in figure 12.148

Figure 37: 11 x 11 Cube Module149 The three storied high house modules with stacking helps in scalability since it was constructed in less than two weeks. The façade is cladded with untreated natural wood. The circulation core is placed in the centre with prefabricated MS Steel.150 The balconies and elevator are made with stacked ceiling creating a shell ceiling. Windows and

147 (Ludwigsbrug, 2017) 148 (Ludwigsbrug, 2017) 149 (Ludwigsbrug, 2017) 150 (Ludwigsburg, 2019) - 58 - door cut-out were also added as per requirements. Cross laminated timber is used in ceilings for insulation. The units are divided with variable floor plans so every unit can be customised with variable stairs which can run parallel or perpendicular with customised fabrication as required by the use type.151

Figure 38: Unit Concept, Cube 11152

The 2.5 room apartment has a standard size of approx. 76 m² and 5.5 room. apartment approx. 117 m².

Figure 39: Floor Plant Type 1153

151 (Ludwigsbrug, 2017) 152 (Ludwigsbrug, 2017) 153 (Ludwigsburg, 2019) - 59 -

The 1 and 4 room apartments vary from 31 m² to 86 m². The 5 room. apartment is 118 m² in range.

Figure 40: Floor Plan Type 2154

Energy supply with photovoltaics – The photovoltaic system provided in the housing system is provided in connection with the kfW 55 standard. The housing standard which dictates if a building is worthy of preserving or not in Germany. The realization of this system is yet to be fully utilised and yet to be understood. However according to the project management team of WBL the project is too complex of calculating ho- listic life cycle analysis of a building from assembling to dismantling.155

Positive Learnings – The growth potential of this housing is seen very high since the capacity of this housing can be scaled to further towns like Stuttgart and adjoining areas.156 The scalability and time factor is the main take away from these construc- tional practices which clearly makes it affordable to the German rental market

154 (Ludwigsburg, 2019) 155 (KFW , 2019) 156 (Roth, 2018) - 60 - demands. Wood as a material thus can be used in fully finished, composite or in panels format for construction.157

Figure 41: Façade with Panels, Battens and Plain Finishes158

Negative Learning – The wooden material and its lifecycle costs are critical to the building. It is very crucial for the untreated wood to be kept ventilated otherwise it may lead to heavy renovation and retrofitting cost. Looking from the social aspect the resi- dents feel uncomfortable with the housings utilised by refuges since it creates a negative impact on the housing brand.159 However, a solid case analysis for the life cycle

157 (Ludwigsbrug, 2017) 158 (Ludwigsburg, 2019) 159 (Concept - Magzine for contemporary living, 2019) - 61 - and dismantling of these construction typologies and lean principles are still not widely discussed.160

3.4 Alho Modular Buildings, Germany (Systembau Modular Building)

The company is a major player from last five decades having multiple disciplinary practice according to the German Leistungphasen LP1-9 phase for modular construction in Germany. The portfolio of works ranges from residential, office to healthcare facilities across European union. As per the company standards seventy percent of the work is made offsite. The design phase involves BIM which is implemented in planning phase along with lean philosophy. Modules averagely take 10 weeks to be assembled on site.161

Unit Typology – The unit typology is based on “LEGO” concept and design. The company focuses on five typologies which are based on varying grid sizes. It varies from 2.62 x 4.00 meters length to 7.75 x 16.75 meters in height. The standard size 3.20 x 4.00 meters in optimum, economical and easy to transport in nature.162

Figure 42: Floor Plan Typology 1163

160 (Ludwigsbrug, 2017) 161 (Alho, 2019) 162 (Alho Gmbh, 2019) 163 (Alho, 2019) - 62 -

The maximum module length is around 20.00 meters x 6.00 meters in width with a standard height of 4.00 meters which can be utilized for a shell depth of 3.50 meters.

Figure 43: Floor Plan Typology 2164

The barrier free design factors are also considered in the same. However, the economical versions are based on standard grid sizes. The high-rise boundary is restricted to 22-meter following DIN 276 standards. The module has been used in all types starting from 1, 2, 3 and 4 room apartments.165

The modules are placed parallelly to scale from two to three rooms. The same modules can be used to scale from three to four rooms. All together forming a cluster which is scalable. Starting with 49 m² to 94 m² every typology is made in a unitized prefabricated system and being repeated. Based on these module parameters different design typologies and variants are already successfully executed in Germany. To achieve more organic forms hybrid systems are adopted when required. The residential typologies executed are Linear, L shaped, U shaped, Closed loop, Zig zag and alternate stagger- ing. Five major module sizes were used in creating these structures.

164 (Alho, 2019) 165 (Alho Gmbh, 2019) - 63 -

Figure 44: Typologies Alho Modular166

166 (Alho Gmbh, 2019) - 64 -

The projects were prefabricated and erected in Dortmund, Dresden, Wiesbaden, Leverkusen, Lendsberg and Dreireich167. Following these systems three two more designs are discussed in detail. All the module typologies used in modular construction are residential apartments. A detailed analysis reflects how modules can be staggered and used in different variations for scalability of the projects considering the time factor. Cost factors were difficult to find as they were confidential.

A. Punkt House – Kaulbachstraße, Bochum.

Year of Construction - 2018 Floors – 4 GFA – 1,378 m2 The structure is a mixture of 3 houses with 14 apartments in total, 42 apartments 7 x 2-room apartments each, 2 x 3-room apartments each, 2 x 4-room apartments each, 3 x 2-room apartments each for wheelchair users. All apartments have barrier- free movement areas. The apartment is also powered by photovoltaics which produce 55kfw energy as seen the figure below.168

Figure 45: Punk Hauser - Block Apartments169

167 (Alho, 2019) 168 (Alho, 2019) 169 (Alho, 2019) - 65 -

The room module is repeated from the 2ZW Zimmer prototype which has been staggered on top of each other. The total construction time was 3 weeks along with finishes. The module is mirrored with a minimum of 1.5 meters of circulation space.

Figure 46: Floor Plan 2zw apartment details170

Figure 47: The Finishes of the apartment171

The module helps in achieving the linearity of design followed by vertical circulation and balcony canopies as seen in the floor plan. The internal partitions are cement

170 (Alho, 2019) 171 (Alho, 2019) - 66 - board portion’s with non-bearing walls insulation partitions. The toilet blocks are prefabricated and put in place during the final handover. The case represents use of modular in a traditional way. Hence a complex project is required to understand the module usage in a wider domain.

B. Zeilen Bebauung, Reicker Straße, Dresden.

Year of Construction - 2018 Floors – 3 and 4 GFA – 6,480 m2 The structure is a mixture of 74 apartments, 10 x 2-room apartments, 25 x 3-room apartments, 37 x 4 room apartments, 2 x 5 room apartments. However, in this case the barrier free design principles are implemented partly.

Figure 48: Zeilen Bebauung Apartment Block (Design Variable Organic Form)172 The 74 residential units in junction with gable ends and plaster facades are lined up in 120 meters long row with smaller units in the canter and balconies located on the either side of the apartment blocks. The total time period required for the construction was

172 (Alho, 2019) - 67 -

38 weeks which comprises 183 modules made out of Alho standard 3ZW apartment block. The areas are bend to very different design needs which was derived from the GDR era design directives.173

Figure 49: Planning for Alho Modular Housing174

The materials used are cement plaster boards for internal partition with wooden floor and decks in balconies. The more controlled condition of offsite construction in the project helped in decreasing 60% of the material waste reaction and 20 %-time savings. It is observed that a hybrid approach in modular construction is required to attain certain goals.175 Thus the case studies refer to create a higher interface, vertical

173 (Alho, 2019) 174 (Alho Gmbh, 2019) 175 (Alho Gmbh, 2019) - 68 - urbanisation and a flexible approach to design flexible modular prototypes which are scalable in nature.

From the above case studies, it was concluded that unit typologies followed by design and specifications play a major role in costing and speeding up construction process. Hence a comprehensive study from leading manufacturer was necessary.

Conclusions -

1. Modular can be treated as the future of the digital nomad. The technology along with the new situation of the modern requirements is changing how we design and executes projects. Modular brings adaptability, transportability and heavy customisation. Cost and Time are the two factors which calculate the profitability of these construction methods. 2. The put in place, plug and play concept helps in determining the value of such methodologies. The learnings from the case studies are implemented considering all the German LP 1- 9 phases. 3. It was observed according to industry standards that the cost breakup for modular should be ideally done as 4% in foundation, 6 % interior finishes, 7% in general services and 13 % in external finishes.176 4. A detail design proposal for SEMODU AG is done here on how the modular prefab can be implemented In European context.

176 (Ekow, et al., 2014 -15) - 69 -

4. Design

4.1 Concept

The author through this thesis, worked on realizing SEMODU’s vision of hybrid modular construction by proposing a design solution with its associated cost and time benefits. The existing modular block sizes being employed in SEMODU projects were used to design this proposal. The sizes of the blocks being as follows:

a. 7m Block - 7.15m X 3.18m b. 6m Block – 6.36m X 3.18m

In this configuration, it was noted that for attaining horizontal or vertical lengths the 7m block is more useful. But in case of intersection or overlap the 6m block was found more useful as its exact size that is 6.36m is double the size of shorter end in both the blocks that is 3.18m. The RCC core of the building is designed in a single 6m block. This minimal size gives the developer more profit due to higher efficiency.

The core has been planned in concrete because of the following reasons:

a. Concrete is ideal for core construction owing to its enough flexibility, reasonable strength and rough usage adaptability. b. The plumbing and sewage pipes carried though service ducts can be tactically placed on the outer surface of the core. As it is better in load carrying capacity and is not weathered overtime with occasional dampness. It neither corrodes like steel nor rots like wood. c. Lifts and staircase are most adaptable with concrete. Concrete has low maintenance unlike steel and can weather heavy traffic unlike wood.

The apartment units are designed in wood owing to its properties of low conductivity/heat loss, good sound insulation, low carbon emission, local abundance and low waste indoor fabrication. The apartment unit can be characterized as follows:

a. 1bhk/ 2-room unit – 2 numbers, 65.85 Sq.M. area b. 2bhk/ 3-room unit – 10 numbers, 87.54 Sq.M. area. c. 3bhk/ 4-room unit – 2 numbers, 110.46 Sq.M. area

- 70 -

Figure 50: Module Configuration (Author’s work)

- 71 -

4.2 Floor Plans

Figure 51: Ground Floor Plan (Author’s work) The apartment footprint comprises of 12 wooden modular blocks of 6m variant, 4 wooden modular blocks of 7m variant and 1 RCC modular unit of 6m variant as core. The ground floor is facilitated with an entrance lobby consisting of letter box area, technical room and bicycle stand. While two apartment units of 1bhk and 2bhk each is designed. These apartments are approached by the core consisting of a staircase and vertical lift. All services shafts are placed adjacent to the RCC core as per the concept.

The 1bhk apartment comprises of an entrance corridor, a living space cum dining area, an open kitchen, a common toilet, a bedroom and two balconies. Apartment is provided

- 72 - with ample storage spaces in living room and bedroom. This apartment size of 65.85 Sq.M. is ideally suited for a single person or a couple.

Figure 52: Typical Floor Plan (Author’s work)

The typical floors i.e. floor number 1st and 2nd are designed with 4 apartment units each. These apartments have an area of 87.54 Sq.M. each which is ideal for a small family house. 2bhk apartment comprises of an entrance corridor, a living space cum dining area, an open kitchen, a common toilet, two bedrooms, an attached toilet to master bedroom, a storeroom and two balconies. The plan is same as the 1bhk unit except the addition of a modular block. A storage room accessible though the common area adds up to the existing storage space of the apartment. Both bedrooms as well

- 73 - as the living space is attached to the balcony area for the out spill especially useful during summer season.

Figure 53: Terrace Floor Plan (Author’s work) The terrace floor is designed with 2 apartment unit of 3bhk configuration. These apartments have an area of 110.46 Sq.M. with additional 65.60 Sq.M. of terrace area. This configuration is ideal for a bigger family. 3bhk apartment comprises of an entrance corridor, a living space cum dining area, an open kitchen, a common toilet, three bedrooms, an attached toilet to master bedroom, a storeroom, one terrace and two balconies. The plan is like the 2bhk unit except the addition of a modular block and change in planning a modular block. A big storage room accessible though the common area adds up to the existing storage space of the apartment. Two bedrooms as well as the living space is attached to the balcony area, while the master bedroom is attached to the terrace area. The terrace area has also been provided with an alternate entrance

- 74 - from the lift lobby to give access to guests for the party activities hosted in the terrace area. The storeroom is attached to the service shaft. As per the user demand, this can also be converted into an additional toilet. The terrace area has a cantilever pergola roof to make it partially protected.

As evident from above explanation, the author has tried to keep maximum modular units of all apartment similar. As the sizes of apartment increases, an additional modular unit is added in the already existing arrangement. This showcases the flexibility of design opportunities in modular construction. These modular blocks can be classified as follows:

a. Block A - Kitchen and Toilet (14 numbers) b. Block B - Bedroom and Balcony (14 numbers) c. Block C – Living room and Balcony (14 numbers) d. Block D1 – Bedroom, Toilet and small storeroom (10 numbers) e. Block D2 – Bedroom and big storeroom (2 numbers) f. Block E – Bedroom and Toilet (2 numbers) g. Block F – Core block in RCC (4 numbers) h. Block G – Letter box area and technical room (1 number) i. Block H – Cycle stand area (1 number) Total number of blocks: 62 numbers

- 75 -

4.3 Façade Elevational View

Figure 54: View 03 (Author’s work)

Figure 55: View 04 (Author’s work) In the building elevation the front and rear façade are overseeing landscape through the balconies. While the front façade contains 6 additional windows and rear elevation contains 8 additional windows. Side elevations have more solid facades and smaller vertical and horizontal windows. The staggered planning arrangement gives a solid and void form of Architecture. The elevation surface is weatherproof panels mounted on insulated exterior walls. Pergola is given as an elevational feature.

- 76 -

4.4 Perspective Views

Figure 56: View 01 (Author’s work)

Figure 57: View 02 (Author’s work)

- 77 -

4.5 Stacking connectors

PPVC modules once fabricated in the plant, are transported to the construction site. These are stacked with 100% precision with each other. A stable, firm and permanent connector is desirable for long life of the modular building. There are varied connection systems depending upon the material and type of PPVC unit. Some can be illustrated as follows:

a) PTMS Join

As shown in figure below, post tensioned modular system can be used to join PPVC modular units in wooden, RCC, or steel structures. The corner surface of such PPVC units are bolted or welded with a connecting plate. The rebar splice is then further fixed to the connecting plate using a rebar tighten coupler. This system has proven to be advantageous in case of water penetration, for reducing fire protection cost and increasing Architectural flexibility. While this is disadvantageous on ac- counts of increased difficulty at site level, decreased work safety, additional wet work on site and limited inspection access.177

Figure 58: Post tensioned modular system178

177 (Sze Dai PANG, 2016) 178 (Sze Dai PANG, 2016) - 78 -

b) Magnetic Connector

Latest innovation in this section is usage of magnetic brackets. These brackets are attached to the corner of PPVC modules using a connecting plate. Connecting plate is first held to wooden module using bolting method. After this, the magnetic bracket is attached to the connecting plate. All four corners of the module are equipped with the combination of steel plates and magnetic brackets. These brackets are also 3- dimentional in shape. That means it has X, Y and Z axis which can attach itself to module on all directions namely top module, side module and back module.

Advantages of this system is its all-round/all-directional rigidity and ease of mount- ing. This technique does not require casting, welding or carpentry works. Its simple application of natural magnetic attachment increases site flexibility and reduces construction time.

c) Bolting with corner cast

This type of technique is used extensively in shipping containers and steel modular units. Furthermore, its application can be extended to wooden modular units too. SHolz Modulbau GmbH employs this technique in its projects. 179

Figure 59: Corner cast used in SH Modulbau180

179 (Modulbau, 2014) 180 (Modulbau, 2014) - 79 -

Figure 60: Detail of corner cast arrangement181

In this type of assembly method, the horizontal wood or steel studs are joined to the corner cast using bolting. Inter-modular assemblies are done using larger bolts with connecting plate stacked in between. The protruding cliff in the corner cast is superim- posed by the void for it in the upper assembly of corner cast. This fixates the initial exact position of the unit and then it is further complimented using bolting.

In the thesis design, author intends to use the magnetic method of assembly owing to its high flexibility and ease of operation.

181 (Sim, 2018) - 80 -

5. Project Scheduling Comparison

Schedule by In-situ method & Modular method:

Theoretical data and the planning for the project is based on personal experience and distinct literature during the project planning phase. In the project, resources, are existing, and subcontracting can be done regarding how it fits in the project.

Briefly, it can be said that planning analysis is done for both methods, which anticipates, and schedules so that coordination and control are enabled, and additional data is collected to refine future planning efforts. As for any project, a strategy and tactic must be developed, how it should be done/executed. In the context of construction management, general results of the planning process are charts and reports, and this will be the manner too as how the results will be demonstrated. In the analysis part, the efforts are aiming at how tasks (quantities and activities) shall be done, which order is needed, what are the resources for it. Practically, as required quantities are established mainly from architectural documents, they need to be organized into meaningful and manageable activities handle and displayable in managerial manners, so that re- sponsibilities can be attributed.

To proceed and detail the planning process, it was necessary to organize and structure & the received quantities via a work break down systematic. The work break down systematic herein focuses on a work break down structure (WBS) with the primary aim to create convenient work units (deliverables) and sub structured project deliverables which later were structured, and sub structured even further, like attributing only specific quantities of an activity to a certain subcontractor solely. The function of the company was defined further as a general contractor, who subcontracts all tasks which cannot be constructed due to lack of stuff or general knowledge and skills within a certain construction field (like HVAC or MEP).

It is necessary to set the execution order of the activities in the ’Network’ view in the right relationship. Via the network analysis, the planner defines based on logic and experience the relationship of the previous created activities, like a finish-start or finish- finish, etc. relationship. These network relations are displayed in the schedule for the traditional method & modular Construction.

- 81 -

5.1 In-situ method chart

In the schedule for traditional, along the recorded day (red line), it is recognizable as to how many activities this interruption had a direct impact on excavation, columns, beams, and slab work. After restarting the work, construction works continued with the same workforce and completed its task with delays observed, which was made up by the time buffer at the end by increasing the resources. Similar drawbacks in the traditional method were identified on each floor.

The following factors were considered in determining the proper construction time and essential activities:

a) Appropriate workforce - how long will which activity take with which size of crews. b) Incentive and disincentive clauses .

c) Time of year (daylight hours), weather considerations (winter work and rain days), and length of duration of project considerations.

d) Delivery of all required materials or equipment and their impact on the project.

e) Owner's completion schedule. This needs to be appropriately detailed with all phases of work in the correct order, and estimated production rates need to be accurate.

f) Owner's project requirements

g) Site conditions and Quality of subcontractors.

- 82 -

Figure 61: Gantt chart in In-situ method, Part 01(Author’s work- Refer Appendices)

Figure 62: Gantt chart in In-situ method, Part 02(Author’s work- Refer Appendices)

- 83 -

5.2 Modular method chart

In the Modular Construction schedule, the planner defines construction time based on the delivery of all required materials or equipment and their impact on the project. The availability of materials is considered and tracked from the manufacturing stage to delivery at the site. The activities taking place, what is there planned duration, how their rate is and w.r.t., the planner considers the ratio of the activities compared with others in the project. It a risk-free flow diagram with a typical finish-start relationship from the predecessor to the successor. The project time required as seen is less as compared to the traditional method due to foundation work at the site being in parallel with fabrication activities at the factory.

As per local knowledge of fabrication plant, it is assumed that one fabrication plant can produce four modular blocks per day. This can be transported to the relevant site together in same numbers.

Figure 63: Gantt chart in modular method, Part 01(Author’s work- Refer Appendices)

- 84 -

Figure 64: Gantt chart in modular method, Part 02(Author’s work- Refer Appendices)

5.3 Results

By comparing the scheduling of In-situ and modular methods, it is concluded that the construction time of the proposed building is reduced by 53.5%.

Construction time(in days)

Modular

Insitu

0 50 100 150 200 250

Figure 65: Schedule graphical comparison (Author’s work)

In the figure below the schedule has been simplified to cover just the floor wise pro- gress over the period. In the modular method of construction, the approach is more linear while in the in-situ system parallel activities has bean engaged. When the scale of modular project is increased, the resources is also increased, and more parallel activities of different buildings can be taken up at the same time. This will give greater benefits to the project developer.

- 85 -

TERRACE

FLOOR 2(Typ)

FLOOR 1(Typ) GROUND FLOOR FOUNDATION

GENERAL

9-Apr-20

9-Feb-20

10-Jan-20 20-Jan-20 30-Jan-20

19-Apr-20 29-Apr-20

19-Feb-20 29-Feb-20

31-Dec-19

20-Mar-20 30-Mar-20 10-Mar-20

Figure 66: Simplified schedule – Modular construction

TERRACE

FLOOR 2(Typ)

FLOOR 1(Typ)

GROUND FLOOR

FOUNDATION

GENERAL

8-Jun-20

6-Oct-20

9-Apr-20

9-Feb-20

5-Dec-20

7-Aug-20

18-Jul-20

20-Jan-20

28-Jun-20

26-Oct-20

29-Apr-20

29-Feb-20 16-Sep-20

31-Dec-19

27-Aug-20

15-Nov-20

20-Mar-20 19-May-20

Figure 67: Simplified schedule – In-situ construction

- 86 -

6. Cost Comparison

6.1 In-situ method

For cost calculation by in-situ method, for structural works certain assumption were made by the author based on the experience due to lack of structural detail design. These assumptions can be illustrated in the table below:

Building Structure Description Measurement Number of columns 28 Nos. Size of each column 0.450m X 0.25m Column length below ground level 2m Size of column footings 2.25m X 2.25m X 0.5m Size of all beams 0.45m X 0.25m Thickness of slab 0.15m Thickness of Lift wall 0.125m

Table 3: Structural Considerations (Author’s work)

All the quantities were calculated as per the author’s design. These quantities were tabulated in cost groups 300 and 400 of DIN 276. Cost of each subhead was taken by BKI (Baukosteninformation 2018, Deutschland) for analysis of present cost val- ues. Rate category from Baukosteninformation was as follows:

Mehrfamilienhauser, mit 6 bis 19 WE, Hoher Standard - Apartment buildings, with 6 to 19 units, high standard.

The total cost (cost groups 300 and 400) of the design proposal came out be 2.7 million € by in-situ method. The unit value of such construction after adding inflation of 1.5% per year comes out to be 2062 € per Sq.M.

These calculations are illustrated in the table below:

- 87 -

Group Unit Quantity Avg. rate in € Total cost in €

311 Pit production m³ 858 34 29155 312 Retaining wall m² 0 184 0 313 Drainage m² 858 8 6946 319 Excavation, other import m³ 858 0 0 310 Pit 321 Ground improvement m² 375 8 2928 322 Shallow foundations m² 375 66 24776 323 Deep foundations m² 375 111 41669 324 Subfloors and floor slabs m² 375 79 29657 325 Flooring m² 375 42 15767 326 Waterproofing of buildings m² 375 19 7133 327 Drainage m² 375 9 3491 329 Foundation, other m² 375 0 0 320 Founding 331 Bearing exterior walls m² 0 126 0 332 Non-load bearing external walls m² 692 152 105161 333 External supports m 0 357 0 334 Exterior doors and windows m² 456 366 166764 335 External wall cladding external m² 692 133 92016 336 Exterior wall cladding inside m² 692 26 17988 337 Unitised outer walls m² 692 917 634426 338 Sunscreen m² 456 168 76548 339 Outer walls, other m² 692 7 5120 330 Outer walls 341 Bearing internal walls m² 0 118 0 342 Non-bearing interior walls m² 2747 63 173048 343 Internal columns m 392 187 73304 344 Interior doors and windows m² 119 392 46648 345 Inside wall claddings m² 843 33 27822 346 Unitised interior walls m² 2747 104 285667 349 Interior walls, other m² 2747 1 3846 340 Interior walls 351 Ceiling structures m² 1353 142 192072 352 Ceiling coverings m² 1353 102 137967 353 Ceiling finishes m² 1353 23 31110 359 Ceilings, other m² 1353 23 31110 350 Cover 361 Roof constructions m² 0 125 0 362 Skylights, roof openings m² 0 839 0 363 Roofing m² 375 166 62316 364 Roof coverings m² 375 32 12013 369 Roofs, other m² 375 21 7883 360 Roofs

- 88 -

Group Unit Quantity Avg. rate in € Total cost in €

371 General installations m² BGF 1353 12 16231 372 Special fittings m² BGF 1353 0 135 379 Of building design fixtures, other m² BGF 1353 0 0 370 Build-in construction 391 Site equipment m² BGF 1353 23 31110 392 Scaffolding m² BGF 1353 9 12174 393 Safeguards m² BGF 1353 12 16231 394 Demolition work m² BGF 1353 3 4328 395 Repairs m² BGF 1353 0 0 396 Material Disposal m² BGF 1353 2 2029 397 Additional measures m² BGF 1353 3 3787 398 Provisional constructions m² BGF 1353 0 135 399 Other measures for building structures, otherwise. m² BGF 1353 0 0 390 Other measures for building structures 411 Drainage systems m² BGF 1353 23 31110 412 water systems m² BGF 1353 40 54105 410 Water, wastewater, gas plants 421 Heat plants m² BGF 1353 12 16231 422 Heat distribution m² BGF 1353 15 20289 423 Room heating radiators m² BGF 1353 20 27052 429 Heating systems, other m² BGF 1353 4 5005 420 Heating systems 431 Ventilation systems m² BGF 1353 10 13256 430 Ventilation systems 443 Low-voltage switchgear m² BGF 1353 0 0 444 Low voltage installation systems m² BGF 1353 28 37873 445 Lighting systems m² BGF 1353 3 3787 446 Lightning protection and grounding systems m² BGF 1353 1 1488 440 Power Installations 451 Telecommunications equipment m² BGF 1353 2 2570 452 Search and signal systems m² BGF 1353 3 4599 455 Television and antenna systems m² BGF 1353 3 3382 456 Hazard detection and alarm systems m² BGF 1353 2 2435 450 Telecommunications and information technology equipment 461 Elevators m² BGF 1353 32 43284 460 Conveyors 471 Kitchen Technical Plants m² BGF 1353 0 0 473 Media supply plants m² BGF 1353 0 0 475 Fire extinguishing systems m² BGF 1353 0 406 470 Use specific systems Additional costs for technical equipment m² BGF 1353 7 9333

Cost: 1st quarter 2018, national average, incl. 19% VAT. 2706720 Cost per unit area 2001 Rate after inflation calculation 2062

Table 4: Cost calculation in In-situ method (Author’s work)

- 89 -

6.2 Modular method

The cost assessment in the modular method was done in this thesis using market analysis as per the scope. The construction cost in modular constructions depends on various factors such as:

a. Level of automation of the fabrication plant b. Method and sequence of fabrication work c. Productivity of labour in the modular setup considering the repetitive nature of work and indoor comfort level. d. Cost of simulation and digitalization in BIM e. Different quality assurance methods f. Staff numbers and level of expertise g. Fabrication plant setup and its running cost. h. Level of construction waste i. Transportation cost

As it is not a conventional method, rates of individual subheads were found to be not readily available in public domain and due to privacy in company policies, the trade secrets cannot reveal in detail. So, the scope of cost assessment in modular construction was limited to market analysis of final rates available in the public domain. These rates were categorised as per the year of completion. This was then assessed to its present value assuming a constant inflation of 1.5% year in Germany. The table below illustrates the average of all such construction costs in varied cities in west and south Germany: Modular Construction Cost Adjusted Cost(in cost BGF(in Cost (pro S. No. Project Name City Company Year Euro KG (Inflation in Source m²) m²) 300+400) 2020, pro m²) IWS Aktuel Magazine, 1 Cube 11 Ludwigsburg 2016 - - 1750 1857.39 Immobilienwirtschaft Jan 2019 Flüchtlingsunter Kreisbaugesellschaft Aktuel Magazine, 2 Winnenden 2016 - - 1735 1841.47 kunft Waiblingen mbH Jan 2019 SH Holz & 3 Vonovia Bottrop SH Holz & Modulbau 2017 3000 4600000 1533 1603.37 Modulbau SH Holz & 4 Wohngebaude Beckum SH Holz & Modulbau 2012 460 660000 1435 1616.27 Modulbau Mehrere SH Holz & 5 Nordhon SH Holz & Modulbau 2016 800 1400000 1750 1857.39 wohnanlagen Modulbau 6 Wohngebaude Lingen SH Holz & Modulbau 2017 - - 1800 1882.22 dw.com

Average 1776.35 Table 5: Cost assessment in modular method (Author’s work) - 90 -

6.3 6C cost-approach

Including the construction cost savings, there are many indirect cost savings also. This is not visible at the first glance, but the developer can benefit financially from it sub- stantially. They can be illustrated as follows:

a) Direct cost savings: Due to bulk orders and repetitive model of work in an indoor environment the fabrication cost is lower than the onsite construction. This saving even increases when the site is placed in a high traffic or dense location.

b) Administrative cost: Due to the repetitive nature of workflow and greater stand- ardisation, lower manpower and management are required for the developer. Many projects can be taken up simultaneously with lesser resources. This is a cost-efficient model.

c) Liquidity: Yield from the project (sale or rent) is faster due to early completion of the projects. Hence the cash flow is improved. The early profit realization can be utilized in the next project to make further profits.

d) Bank: Interest rate and total interest sum is lower due to short construction time.

e) Investor: Modern construction method and delivery pattern enhances the market image. Market image brings greater number of projects in a short duration of time and investor confidence is boosted. This brings a chain reaction of profit.

f) Waste/Quality/Safety/Risk: Snagging, defects and site disruptions are reduced significantly. This is rather replaced by high quality and standards of construction. This in turns give short term as well as long term financial benefits.182

182 (Krug, 2013) - 91 -

Direct cost savings

Waste/ Administ Quality/ rative Safety/ cost Risk

6C Cost Approach

Investor confiden Liquidity ce

Bank reliance

Figure 67: 6C Cost Approach (Author’s work)

6.4 Results

By comparing the construction cost between conventional and modular, we can con- clude a difference of approximately 13.5%. As illustrated above this only mounts to be direct cost saving. Indirect costs are difficult to comprehend in terms of numbers but has potential to further enhance the profit margins for the developer many folds.

€ 2500.00

2000.00

1500.00

1000.00

500.00

0.00 Cost Conventional (pro m²) Cost Modular(pro m²)

Figure 68: Cost graphical comparison (Author’s work)

- 92 -

7. Conclusion

The author was successful in the following area in the thesis work: a) Proposal of a model for SEMODU’s vision in the hybrid modular construction industry with reference to current market trends in Germany. b) Implementation of ConREM’s curriculum to calculate costs, project schedule, inflation and BIM. c) Implementation of experience gained in Germany in the area of modular construction via internship with SEMODU AG. Current exposure of modular construction and real estate development added to the quality of this thesis work. d) Implementation of previous Architectural and Construction experience in this thesis work to reach practical inference.

Through this thesis work, with study of historical modular construction attempts around the globe and recent case studies in Germany, author was able to establish ground knowledge of this type of construction method. Author studied the possibility of hybrid construction and best combination of building material to realize the vision of SEMODU was established in form of combination of RCC (core) and Wood (Shell). Author has successfully given a design proposal for such a hybrid modular building considering the modular block sizes presently being used by SEMODU. Detailed design is worked out in terms of construction level detail, functionality and aesthetics. The resultant design made no compromises on Architectural value of final product. It will be difficult for a user to make out without prior knowledge that the building is conventional or modular, due to its regular design.

The author then comprehended this design for comparison works. The same design was compared in conventional construction method and modular construction method. It was found that the construction time was halved, and the direct cost of construction was reduced by 13.5%, when modular construction was employed over the conventional techniques of construction. Other than these direct benefits, author showcased a 6C cost approach model in which various area of indirect costs are also benefited in modular construction. This adds up to the profit margin of the developer even further.

- 93 -

Scalability of this model:

The scope of this thesis work assumes designing a single modular building to evaluate various benefits related to modular construction. But when this model is replicated on a larger scope say a township or a Highrise building, the benefits are slated to be even higher.

Through the effort of planning it is, that one can anticipate and influence happenings and gains a proper (planned, anticipated, deliberate) value, upon or towards all occa- sions/events can be correlated. Briefly, it can be said that planning analysis, anticipates and schedules so that coordination and control are enabled, and additional data is collected to refine future planning efforts. As for any project, a strategy and tactic must be developed, how it should be done/executed. In the context of construction management, general results of the planning process are schedules & this will be the manner too as how results can be demonstrated for a project to be successful. For large real estate project, various parameters of cost & schedule will differ to what considered in the approach of this thesis & will be beneficial by considerations of the following factors: a) Planning & Design: As the approach found is more optimistic in view of the schedule & design, similar planning & design considerations can be considered for a large project having identical modules to be used. As the industry trends to adopt the repeated design, the cost will decrease & subsequent decrease in time for construction. b) Site Overheads: Cost for security & managing various site overheads due to social factors such as safety & health, various weather conditions factors decrease the schedule delay & subsequent cost in a large project. c) Rework: One of the significant wastes in construction, rework for a process will be reduced by adopting approach & subsequently scheduled for a project will improve by early detection of defects through proper quality control in manufacturing units.

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Declaration of Authorship

I herewith formally declare that I have written the submitted dissertation independently. I did not use any outside support except for the quoted literature and other sources mentioned in the paper. I clearly marked and separately listed all of the literature and all of the other sources which I employed when producing this academic work, either literally or in content. I am aware that the violation of this regulation will lead to failure of the thesis.

Shashank Pandey

______Student´s name Student´s signature

S0562622 20.01.2020

______Matriculation Berlin, date

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