DEGREE PROJECT IN ENVIRONMENTAL ENGINEERING, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2019 Urban form and sustainability Comparison between low-rise "garden cities" and high-rise "compact cities" of suburban areas EFSTATHIA VLASSOPOULOU KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ARCHITECTURE AND THE BUILT ENVIRONMENT TRITA TRITA-ABE-MBT-19672 www.kth.se Urban form and sustainability Keywords: garden cities, compact cities, sustainability, density, life-cycle assessment, sustainability performance indicators Degree project course: Strategies for sustainable development, Second Cycle AL250X, 30 credits Author: Efstathia Vlassopoulou Supervisors: Tove Malmqvist (KTH) Gustaf Edgren (TMF) Examiner: Sara Borgström Department of Sustainable Development, Environmental Science and Engineering School of Architecture and the Built Environment KTH Royal Institute of Technology Abstract Urbanization and climate change are two of the most important issues of our days. Many attempts have been made to define the most sustainable way to organise cities in order to cope with the increased population, while simultaneously being climate friendly, socially acceptable and economically viable. This master thesis focuses on the comparison of the sustainability performance of two particular theoretically planned urban forms, located in the suburban area of Stockholm – a “compact city”-like neighborhood and a “garden-city”-like neighbourhood. It was decided that the focus would be on the carbon footprint of the representative residences of each urban form, with the help of Life Cycle Assessment (LCA); and that overall sustainability criteria for neighbourhoods would afterwards be assessed, having a certification system for sustainable neighbourhoods (CityLab for districts, in particular) as a framework for a – mostly- theoretical assessment. After the exploring of the differences in the sustainability performance (environmental and social) of the two assessed urban forms, a discussion is made concerning the relationship between urban form and sustainability and conditions under which the most sustainable urban form could be achieved. The results of the analysis highlight that the concept “one size fits all” cannot conform to urban planning decisions, since cities should be able to adjust to the needs of each generation. 2 Table of Contents Chapter 1 - Introduction --------------------------------------------------------------------------------- 7 Chapter 2 - Research question and objectives ------------------------------------------------- 10 Chapter 3 - Background ------------------------------------------------------------------------------- 12 3.1. Definition of sustainable development ------------------------------------------------------------ 13 3.2. Elements of urban form in relation to sustainability ------------------------------------------- 13 3.2.1. Density---------------------------------------------------------------------------------------------------------------- 14 3.2.2. Land uses ------------------------------------------------------------------------------------------------------------ 15 3.2.3. Building types (life cycle carbon footprint, social aspects) ----------------------------------------------- 17 3.2.4. Transport infrastructure ----------------------------------------------------------------------------------------- 21 3.2.5. Integrated features ------------------------------------------------------------------------------------------------ 22 3.3. Characteristics of the main urban development forms of the developed countries---- 23 3.3.1. Urban sprawl -------------------------------------------------------------------------------------------------------- 23 3.3.2. High-rise compact cities/neighbourhoods ------------------------------------------------------------------- 23 3.3.3. Garden low-rise cities/neighbourhoods ---------------------------------------------------------------------- 24 Chapter 4 - Methodology ------------------------------------------------------------------------------- 26 4.1. General methodology followed to answer the research question--------------------------- 26 4.2. Objective 1 - carbon footprint from the residential sector------------------------------------ 27 4.2.1. Multi-storey dwellings -------------------------------------------------------------------------------------------- 28 4.2.2. Single-family dwellings ------------------------------------------------------------------------------------------- 29 4.3. Objective 2 - Comparison of the sustainability performance --------------------------------- 31 4.3.1. Certification systems for sustainable neighborhoods ----------------------------------------------------- 31 4.3.2. Part I. - Default set-up of the neighborhoods ---------------------------------------------------------------- 32 4.3.3. Part II. Assessment with sustainability performance indicators ---------------------------------------- 38 4.4. Objective 3 - Critical Assessment and Discussion ----------------------------------------------- 40 Chapter 5 - Limitations-Assumptions ----------------------------------------------------------- 41 Chapter 6 - Results and Discussion ----------------------------------------------------------- 44 In this chapter, first the extracted data concerning the Blå Jungfrun will be presented (section 6.1.), followed by the results from the analysis performed for this report regarding each research objective (sections 6.2. and 6.3.) ------------------------------------------------------------------------------ 43 6.1. LCA data extracted from the existing report about Multi-storey dwellings (Blå Jungfrun) -------------------------------------------------------------------------------------------------------- 43 6.2. Compare the carbon footprint of the indicative residences of each urban form -------- 43 6.2.1. Single-family houses LCA results ------------------------------------------------------------------------------- 43 6.2.2. Comparison of Linnea and Blå Jungfrun LCA results ------------------------------------------------------ 45 3 6.3. Compare the sustainability performance (environmental and social) of the two urban forms. ------------------------------------------------------------------------------------------------------------- 47 6.3.1. Summary of results ------------------------------------------------------------------------------------------------ 48 6.3.2. Analysis of the neighbourhoods regarding each sustainability indicator ------------------------------- 48 6.3.3. Resulting comparative performance of the two urban forms-------------------------------------------- 57 Chapter 7 - Sensitivity Analysis ------------------------------------------------------------------- 61 7.1. How could different fuels or modes of transportation affect the LCA emissions at A4 stage of Linnea? ------------------------------------------------------------------------------------------------ 62 7.2. How does concrete affect the compact city results? -------------------------------------------- 63 7.3. How does the choice of land use affect the results? --------------------------------------------- 64 7.3.1. Population density and meeting places for the garden city ---------------------------------------------- 64 7.3.2. Provision of basic services, facilities and meeting places in garden cities ---------------------------- 65 7.3.3. Prerequisite for GAF above 0,5 for both forms and space occupied by private gardens in the garden city------------------------------------------------------------------------------------------------------------------- 66 7.4. How does the choice of energy supply system affect the results? --------------------------- 67 7.5. How does the provision of parking space affect the results? --------------------------------- 68 Chapter 8 - Discussion-Suggestions ---------------------------------------------------------------- 70 8.1. Relationship between Urban form and Sustainability ----------------------------------------- 71 8.1.1. Usefulness of CityLab indicators-------------------------------------------------------------------------------- 71 8.2. Discussion concerning improvement of the two urban forms based on results and sensitivity analyses ------------------------------------------------------------------------------------------- 72 8.2.1. Knowledge acquired through the performed default analysis ------------------------------------------ 72 8.2.2. Improvements for the default assessed Garden cities ----------------------------------------------------- 72 8.2.3. Improvement of compact assessed cities --------------------------------------------------------------------- 74 8.2.4. General improvement for the typical (not the default assessed) format of the two urban forms75 8.3. General large-scale suggestion ----------------------------------------------------------------------- 76 Chapter 9 - Conclusions -------------------------------------------------------------------------------- 79 References -------------------------------------------------------------------------------------------------- 83 Appendix ----------------------------------------------------------------------------------------------------- 90 Appendix A ------------------------------------------------------------------------------------------------------ 90 Appendix B ------------------------------------------------------------------------------------------------------------------- 98 Appendix C -----------------------------------------------------------------------------------------------------------------