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08.18 Timber in architecture supplement CONTENTS
4 Industry news
6 COMMENT: The disruptive power of tall timber Kevin Flanagan of PLP Architecture explains how the firm’s pioneering research projects to build unprecedented tall engineered timber structures is driven by an agenda of increasing quality of life in ‘smart cities’ of the future
9 COMMENT: Why timber is the answer ADF caught up with Jeremy English of S dra to discuss why he feels timber is the solution to the UK’s housingӧ crisis, and how the material can help architects adopt less labour-intensive, offsite building techniques PROJECTS 12 Swimming among the timbers A competition-level swimming pool has been constructed at a Surrey school, integrating a high level of quality in the design of its timber elements while embracing its ancient woodland surroundings. Adam Cossey from the project’s architects Hawkins\Brown, tells Jack Wooler how it was achieved 12 18 Keeping the past in view Architect RO&AD’s timber watchtower project in the Netherlands engaged the community in innovative ways to generate a new enthusiasm for the area’s rich history. Sébastien Reed reports
FEATURES
23 Going with the grain Gregg Wright of Reliance Veneer explains how the demand for decorative timbers combined with modern manufacturing techniques not only makes environmental sense, but can also enhance design 25 The membrane method 18 Adam Ford and John Mellor of Protect Membranes discuss how to achieve low U-values using membrane technology with low emissivity
27 The timber revolution Sarah Harding of Accsys Group reports on how the UK is experiencing a revolution in timber in architecture, as designers and specifiers increasingly embrace the material’s combination of beauty and environmental advantages
29 The most sustainable material of them all Sean Parnaby of West Port says that the timber industry is gradually winning the war against misconceptions about what he claims is not only the oldest, but the best fenestration material 23 ADF08_Timber Supp 03-18_ADF Flatplan 27/07/2018 10:18 Page 4
4 NEWS
Managing Editor James Parker [email protected]
Advertisement Manager/ Joint Publisher FROM Anthony Parker [email protected]
Assistant Editor Sébastien Reed THE EDITOR Editorial Co-ordinator Shelley Collyer
Editorial Assistants here is a strong case to be made that timber has now become architects’ favourite material, Roseanne Field Jack Wooler following a few decades when steel and glass (not to mention the perennial 20th century contender, concrete), dominated. Architects, driven by the twin desires to build more sustainably Studio Manager T Mikey Pooley and with wellbeing at the core, have always turned to timber. However with modular housing now Production Assistants becoming flavour of the month/year, the triple threat is going to lead to some waves breaking across the Carmen Simpson Georgia Musson whole construction industry.
Sales Executives Suzanne Easter Ian Fletcher The realities of embracing not only volume housebuilding, but a new construction approach in the form of Kim Friend modular timber, seem to have proved more daunting than expected for Legal & General. Notwithstanding, Steve Smith the insurer now looks to be ready to build its first modular timber homes, fresh from its new factory. Audience Development Manager Apparently, L&G Homes struggled to find CLT of the desired tolerances to do what it wanted, which Jane Spice shows that while the CLT revolution is truly that, doing it in practice is far from simple. Managing Director Simon Reed L&G Homes aims to build between 10,000 and 15,000 homes a year within five years, and owning Cala Advertising & Administration Homes means that it has a foothold in sites, meaning it has at least some of the challenges covered. It is t 01435 863500 [email protected] going to build 650 homes for rent on a brownfield site it has acquired next to a new Crossrail station in www.architectsdatafile.co.uk Woolwich, which sounds like the ideal showcase to present what modular CLT can do. Press Releases [email protected] The big issue is that this kind of innovation is really going to put the cat among the pigeons in terms of the Subscription circulation enquiries UK’s traditional (some might say moribund) adherence to brick-and-block house construction. While [email protected] apartment blocks have embraced various alternative materials over the decades (and are arguably a better netMAGmedia Ltd use of land), housing tends to be in the grip of the major volume builders, who prefer the supply chains Cointronic House Station Road, Heathfield and methods (not to mention the density levels) they know, and can control. East Sussex, TN21 8DF
netMAG Modular timber is of course an entirely different way of doing it, ensuring things are sorted pre-site, and media publishing – vertical search with minimal time and effort – comparatively – spent on site. The beam-and-post simplicity of the Tallwood House project in Vancouver (which was reported in ADF March 2018), shows just what is possible in tall buildings – an 18 storey timber structure, albeit with concrete cores. The question is,
Annual subscription costs just £48 whether major UK builders will embrace, or resist, the rise of timber in housebuilding. for 12 issues, including post and packing. Phone 01435 863500 for details. Individual copies of the publication are available at £5 each In this supplement devoted to design and construction using timber, we cover all bases, from a inc p & p. All rights reserved watchtower in the Netherlands, to PLP’s staggering proposals for tall urban towers constructed entirely No part of this publication may be reproduced or transmitted in any form from wood. We hope you find it illuminating reading. or by any means, electronic, mechanical, including photocopying, recording or stored in any information retrieval system without the express James Parker prior written consent of the publisher. Although every effort is made to Editor ensure the accuracy and reliability of material published in Architects Datafile, the publisher can accept no responsibility for the claims or opinions made by contributors, TIMBER IN adf manufacturers or advertisers. ARCHITECTURE 08.18 ON THE COVER... Editorial contributors to this journal may have made a payment towards Pompejus Tower by RO&AD Architecten is a structure the reproduction costs of material built from modified timber and steel in Halsteren, the used to illustrate their products. The manufacturer of the paper used Netherlands, and designed to lean at a sharp 60 within our publication is a Chain-of- degree angle, pointing towards a historic fort. Custody certified supplier operating within environmental systems certified to both ISO 14001 and For the full report, go to page 18 EMAS in order to ensure sustainable production. Cover image © Katja Effting Printed in England
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NEWS 5
RESIDENTIAL Scottish CLT scheme sets a precedent
At seven storeys, construction firm CCG superstructure, working collaboratively (Scotland)’s recently completed Ellerslie with Eurban at detail design stage to Road development is being hailed as ensure a smooth offsite manufacture and Scotland’s tallest timber building. onsite assembly process. The entire It is also Scotland's first multi-storey superstructure is built from Stora Enso domestic CLT building, and its Building PEFC certified CLT including the common © CCG (Scotland) Warrant approval has set a precedent in areas and lift shaft. The lift shaft’s Scotland as a result of evidence supplied structural walls are formed by 100 mm to Building Standards Scotland, Glasgow thick CLT panels tied together to form a construction of Ellerslie Road, which City Council and Scottish Fire & rigid tube with the shaft independent from equates to a total of 757 tonnes of CO2 Rescue Services. the CLT separation wall between lobby being removed from the earth’s atmosphere. Built on the banks of the River Clyde at and apartment. The shaft is restrained Other key benefits of building with CLT Yoker, a town just west of Glasgow, laterally at each of the seven floor levels, include the material’s inherent air-tightness Ellerslie Road provides 42 one, two and with the panels forming the lobby slab and and thermal properties, which mean that three bed contemporary mid-market rent capped with a 120 mm thick CLT ‘lid’ used residents will benefit from energy savings apartments for Sanctuary Homes, part of to fix the hooks to install the lift without when compared to traditional methods of Sanctuary Group. The new building, which the need for any steel lifting beam. construction. Solar PV panels have also was designed by MAST Architects, A bespoke platform is used to support been installed on the roof providing optimises the efficiency of CLT with six the superstructure due to the lightweight long-term energy savings on residents’ apartment modules arranged around one nature of CLT and the exposure to wind energy bills. central stairway in a ‘T’ shaped form. loadings along the river. The superstructure Building with CLT resulted in reduced Apartments are designed around a includes design features to provide construction time thus minimising impact standard template used by CCG for all enhanced resistance to disproportionate on the surrounding community, with the residential units, however CLT’s ability to collapse, and this has encouraged the entire seven-storey superstructure installed achieve long, uninterrupted spans allowed Institution of Structural Engineers and wind and watertight in just 16 weeks. for a flexibility in the layout of apartments (IStructE) to start a review process for Part Ellerslie Road is the subject of two from floor to floor which would have A3 – ‘Building Regulation Disproportionate academic research programmes looking at been more constrained with traditional Collapse’ as it has recognised that there are factors including CLT’s airtightness, forms of construction. a number of forms of construction that acoustics, thermal performance, Engineer Smith and Wallwork were would benefit from a review. productivity, LCA/whole life costing, and responsible for the design of the CLT 1240 m3 of CLT was used in the the building’s interaction with wind.
EDUCATION sector are facing severe skills shortages and similar gaps exist in many MSc on timber architecture launched countries overseas.” He added: “These employers are looking for graduates with a combination Edinburgh Napier University has a design professional within the timber of technical know-how and commercial introduced an MSc on Timber sector – one of the fastest growing parts of awareness in the design, manufacture and Architectural Design and Technology – the building industry in many countries assembly of timber buildings and struc- thought to be the first of its kind in the UK. around the world. tural systems. We have designed the The programme is designed for The programme has been developed programme to address this demand.” graduates in architecture, architectural by Edinburgh Napier’s Institute for The university said that graduates of the technology and other construction Sustainable Construction in consultation programme will be “equipped for employ- professions who want to become part with professional bodies and the ment in design-build firms, fabricators, of the growing international move timber industry. builders and developers; along with towards innovative and high-performance Institute director Professor Sean Smith professional and technical roles in the timber building. said: “Our market research shows that associated architectural and engineering The MSc will equip students to work as employers in the UK timber building consultancies”.
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COMMENT The disruptive power of tall timber Kevin Flanagan of PLP Architecture explains how the firm’s pioneering research projects to build unprecedented tall engineered timber structures is driven by a wider agenda of increasing quality of life in ‘smart cities’ of the future
he essence of our firm’s design is innovation, be it the world's Provocative proposals smartest and most sustainable building yet, The Edge in PLP Architecture, with University of Cambridge Centre for Natural TAmsterdam, research proposals to improve urban movement Material Innovation, and structural engineers Smith and Wallwork, (SkyPod and CarTube), or to build taller than ever before in timber are collaborating on provocative feasibility research into mixed-use – the Oakwood Timber Tower series. All have at their core the aim engineered mass timber/CLT high-rise towers for 21st century cities. of making our quality of urban living and wellbeing better. The Oakwood Timber Tower proposals – one in London, and two By 2050 the residential population of 150 of the world’s great in the Netherlands – have been designed to improve our sense of cities are projected to double. The existing challenges of insufficient urban wellbeing, while being a response to anticipated future needs. housing in London will become more acute. With population Oakwood Timber Tower 1, a feasibility study for an 80-storey, increases, cities will naturally densify, high-rise solutions will 315 metre engineered mass timber and CLT tower at London’s predominate, and the CO2 footprint will increase massively without Barbican, was hugely provocative for the construction industry. It mitigation and active intervention. Can we meet the challenge? contains a total of 1,000 ‘micro-housing’ units, in a 1 million ft2 Our goal should be to improve the quality of life and freedom of mixed use tower, with new low-rise terraced accommodation above choice, allowing cities to thrive. The provision of housing seems an existing structures. intractable urban challenge however. Cost seems to be driving away For the second iteration, Oakwood Timber Tower 2, ‘The Lodge’ the best and most innovative idea makers – the millennials – as the was put forward with innovative Netherlands-based developer city gentrifies. The younger innovators on which the city ultimately Provast NL. This project extended our knowledge of the potential depends are dispersed and forced away. of engineered timber technology with a 130 metre centralised oval Can we advance a new paradigm, reducing the seeming disruption design, as a more ‘real-world’ initiative. A series of ‘straight’ and extortionate costs of residential housing development through the harnessing of innovations such as robotics, Big Data, crowdsourcing, and the latest materials?
In support of smart cities Smart cities of the future will be incubators that hatch innovative ideas, such as the new logistics apps, like Blockchain, that are creating a more direct and responsive global marketplace. London needs to rethink and realign its urban economic imperatives, to include greater influence of millennials in transforming the design of our cities to meet their needs, incorporating 5G networks. As The Edge illustrates, ‘smart’ buildings flourish within smart cities, and 5G will drive technology, from AI to health benefits in offices from WELL Standard-like research and city design initiatives. Can we make daily life in our future cities a healthy experience, reducing stress while increasing stimulation? Can design, architecture and materials be used to promote this healthfulness and de-stressing? Based on science and anecdotal evidence, the answer seems to be that engineered mass timber looks to have terrific Courtesy of PLP Architecture for developer Provast NL potential to improve urban dwellers’ quality of life.
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This project extended our knowledge of the potential o
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8 COMMENT
three-storey glulam columns rise up within the hyperboloid tower obvious being that it is a renewable resource, unlike prevailing form, this slender basket weave grid shell creating a dynamic construction methods using concrete and steel. The research is also ‘airframe’ silhouette (see image below). investigating other potential benefits, such as reduced costs and Oakwood Timber Towers 3 is the most recent investigation and a improved construction timescales, increased fire resistance, and further iteration of the concept. The Lodge 2/Treehuis, again in the significant reduction in the overall weight of buildings. There is 40 Netherlands, employs a cellular ‘tube within a tube’ construction. per cent less waste immediately, and greater potential for second and third use for the material. Timber benefits Our disruptive research into tall engineered timber buildings Our team has long been investigating the myriad benefits of also looks towards creating new design opportunities. Timber engineered mass timber. As a tower, engineered mass timber construction may have a wider positive impact on urban has the potential to create an architecturally more pleasing, relaxed, environments and built form than we have currently envisioned, sociable and creative urban experience; free, abundant, renewable and offers opportunities not only to rethink the aesthetics of and sustainable. buildings, but also the logistics and cost; in light of this new Beyond the engineering and the sequestering of CO2, we as technology and potential savings of production based from humans have an affinity for nature, and timber. We are calmer and computer-driven precision – BIM, GC, and Blockchain – and more sociable when this natural material is in sight, our heart rate robotic staged construction methods. Building faster, lighter, at slows, we are less stressed, and apparently, more sociable; such better quality, with improved resilience, and in a significantly more settings evidently promote healing. environmentally responsible way. People naturally associate timber interiors with the out of doors, The light and high precision prefab components lead inevitably and some believe that the ‘phytoncide’ VOCs produced by timber to automated and robotic construction methodology and ‘flat are similar to the benefits of walking in a forest glade, claiming they pack’ cost efficiency. In Canada, which uses a high degree of boost our immune system. Tests have shown that it lead to increased modular timber, construction is 10-15 per cent cheaper now – one concentration in children of all abilities. Claims have also been can well imagine with a far greater sourcing and a great volume made that in timber buildings one half of our brain gets ‘smarter’, and potentially doubling of product perhaps a 50 per cent we recover faster from surgery or illness (perhaps related to timber reduction could be achieved. The 20 per cent time savings interiors’ restfulness), energy levels increase, and sleep improves. should be possible to be reduced as well to say 50 cent with fuller As a harvested natural material, mass timber has a high visual production take up. appeal to the human psyche, encouraging a sense of wellbeing among residents. Modular cross-laminated timber (CLT) establishes Housing future a new level of precision, quality control and fire protection; bringing The average home in London is £540,747, thats £135,000 or 25 a new structural aesthetic and elegance in form. per cent higher than say Boston in the US. One wonders can all the As well as being faster in construction, and less disruptive to promised efficiencies of Big Data be brought to bear on to meet an the local neighbourhood, modular CLT construction is quieter, so oncoming demand. Can the market achieve new efficiencies in the could also conceivably be used to extend many existing concrete housing market, what would happen to the London market if the buildings upwards substantially. For example, we understand that a price were halved, and construction times were significantly recent feasibility study was done in Toronto to double the height of reduced, would London see a renaissance as a vibrant home of an existing Four Seasons Hotel. young new ideas post-Brexit ? As a provocation to the industry, we are stretching the Despite harnessing new technology and new forms of theoretical limits of plant-based materials with our tall timber shared financing like crowd-sharing, and with Big Data and concepts, nearing, or going just beyond the easily feasible. This Blockchain logistics brought to bear, we can only streamline an requires further collaborative study including establishing ongoing already overly complex and burdensome methodology. We are testing programmes. better to invest the notion of people and cities, and harnessing their new ideas for the future, than to promote older, laborious Mixed-use residential high-rise and uneconomical methodologies. We need to look again with new The use of timber as a structural material in tall buildings is an area eyes at established methods which are now lacking. of emerging interest for a variety of potential benefits; the most One new idea, crowd-sharing debt for new micro-housing developments, can make the broader populace direct investors in the quality of their cities. This could be part of the solution to establishing new housing models better suited to young urban professionals in idea industries, and key workers. Similarly, we are finding engineered mass timber to be a truly 21st century material, as a response to several challenges including increasing CO2, and growing high residential demand, globally. As our society moves by necessity towards the creation of smart cities and valuing idea creation, this ‘New’ 21st century material seems to also answer future potential by making our cities better places to live together; better places to think a new and act anew.
Courtesy of PLP Architecture Kevin P. Flanagan is senior partner at PLP Architecture for developer Provast NL International
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COMMENT
Why timber is the answer
ADF caught up with Jeremy English of S dra to discuss why he feels timber is ӧ the solution to the UK’s housing crisis, and how the material can help architects adopt less labour-intensive, offsite building techniques
What do you see as the main challenges facing the through building, production and transportation, typically UK housing industry? accounting for around 30-50 per cent of a project’s entire carbon Government commitments, underpinned by the prospect of Brexit footprint. It takes very little energy to convert trees into timber for depleting the labour force and an ever-increasing necessity for construction, for example, while the building process typically sustainability, means the housing industry cannot possibly deliver requires a fifth of the vehicle deliveries demanded by concrete. 300,000 new homes a year using traditional building methods Aside from this, its insulating properties make buildings cheaper, alone. The coming years will inevitably see scrutiny turn toward greener and easier to heat post-construction. how these houses will be built, how quickly they can be built, and Timber is also lightweight, versatile and easy to handle and how much money they’re likely to cost. Timber may prove to be install – all of which helps reduce construction time by around a the answer that is needed. third and typically result in less-expensive building. It does sometimes mean that timber is thought of as a weaker form of So, what’s so special about timber? construction, but that certainly isn’t true. Timber is remarkably First and foremost, timber is the ultimate sustainable building strong and durable, guaranteeing that regardless of speedy material, which is an important asset given this government’s plans construction, there’s no compromise in quality. to reduce carbon emissions by 3 per cent each year up until 2050. As trees grow, they naturally absorb harmful carbon dioxide, How do these qualities help facilitate offsite locking CO2 into the wood rather than releasing it into the modular housing? At a time when the construction industry is under increased atmosphere. Timber’s overall embodied energy is also the lowest of any mainstream building material. This factors in energy expended pressure to build quickly and sustainably, timber offers an often
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England and Wales. Factory-based construction was up 15 per cent in Germany and Japan last year and structural timber exports to the US are expected to continue increasing. With timber already leading the way in other parts of the world, the UK must step up its use of timber to help achieve its own housebuilding objectives.
What potential obstacles are there to the progress of modular homes? Although modular homes are typically less expensive than traditional building methods, acquiring sites and constructing the factories to put them together can be costly, which may mean we see a somewhat slower uptake from certain housebuilders and developers. Legal & General (L&G), however, spurred on from last year’s Autumn Budget, has looked to accelerate its housebuilding having already launched a £55m offsite housing factory in Yorkshire in 2016. It is the largest housebuilding factory in Europe and subsequently delivered homes to the Richmond Housing Partnership discussed earlier. inspirational alternative construction solution. The material’s James Lidgate, L&G Homes CEO commented that its ability to streamline the offsite manufacturing process can help cut multi-tenure approach to housebuilding could help them build time by as much as 50 per cent and a timber frame can be “achieve a 50 per cent improvement in delivery,” suggesting that precisely pre-cut and easily put together with less manpower, fewer eventual housebuilding capability more than makes up for the deliveries to site, and minimal debris left behind. initial expense. Manufacturing in a controlled factory environment also means that the great British weather is never a problem! It’s less likely What benefits does timber offer architects? there will be any defects, risk of injury is reduced, and with greater Timber’s natural beauty and versatility is hard to replicate, and a potential to automate more steps of the manufacturing process, timber-framed building can provide a highly desirable aesthetic. dependence on traditional skilled labour is reduced. All these Timber naturally grows more slowly in colder climates, resulting factors help to cut costs, making timber construction a in a tighter grain and growth rings, which not only signifies better dramatically more cost-effective form of construction than stability and greater strength, it also provides an additional traditional building methods. aesthetic feature. And, if you’re working with timber that will be exposed and on Are we seeing people’s perceptions of timber show, it offers a wide range of aesthetics that give great design construction changing in the UK? flexibility. It can vary in colour and texture, be painted in any Here in the UK timber construction is making great strides. Legal colour, waxed and varnished, carved, cut, glued and nailed – or just & General, for example, took over 9,000 homes from Richmond left as it is. It can also be clad in external materials, allowing it to Council and committed to building thousands of timber-framed complement specific local regulations and planning requirements. flats and houses offsite for Richmond Housing Partnership (RHP). It’s no surprise that we’re seeing more and more timber RHP bought them for at least 15 per cent below the standard cost structures being built. It’s a great selling point for eventual for onsite construction and is set to rent them out for just £600- occupants to know that their home or office has not damaged the £700 per month. This is staggering considering rent for a single-bed environment but has in fact locked in and helped mitigate the flat in the Richmond area typically costs upwards of £1,000. It’s a effects of otherwise potentially harmful carbon dioxide. great example of timber construction being used to help deliver Speed and ease of construction are also two key benefits. Waugh truly affordable homes. Thistleton Architects, for example, has long championed We’ve also very recently seen Mayor Sadiq Khan agree to sustainable timber construction and put together Murray Grove contribute £50,000 to fund a ‘developers’ toolkit’ to help simplify and Dalston Lane – two landmark projects. Nine-storey Murray the construction of offsite homes in London. It’s a significant step Grove was the first tall urban housing project to be constructed forward for modular housing in London and represents entirely from pre-fabricated solid timber and was put up by a team recognition that modular housing truly can help fix the UK’s of four in just 27 days. Dalston Lane required just 111 deliveries of ‘broken’ housing market. materials during construction, compared with over 700 deliveries The case for timber outside the capital is also strong. Lovell, on a typical concrete and steel project. And earlier this year, Morgan Sindall’s housebuilding arm, has recently signed a £45m Sumitomo Forestry revealed plans to build W350 – a 70-storey, modular housing deal with Homes England under the 350-metre timber skyscraper in Tokyo. W350 would become the Government’s Accelerated Construction initiative. 200 homes will world’s tallest timber structure and the tallest building in Japan. be built with modular closed panel, pre-insulated timber frames Projects like these not only help raise the profile of timber and roof cassettes in Leyland, Lancashire. Lovell has said that this construction, but also offer all the evidence and reassurance people method could double the speed of construction. need that timber is the building material of the future. There is, however, still work to be done. Timber frame construction currently accounts for a massive 76 per cent of Jeremy English is sales director at Sӧdra – Sweden’s largest housebuilding in Scotland, but just a quarter of housebuilding in forest-owner association
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BUILDING PROJECTS CITY OF LONDON FREEMEN’S SCHOOL POOL ASHTEAD, SURREY Swimming among the timbers A competition-level swimming pool has been constructed at a Surrey school, integrating a high level of quality in the design of its timber elements while embracing ancient woodland surroundings. Adam Cossey from the project’s architects Hawkins\Brown tells Jack Wooler how it was achieved
he new pool for City of London The architects utilised innovative offsite Freemen’s School, in Ashtead, fabrication techniques to create the new TSurrey, uses state-of-the-art timber building’s timber frame. The material construction and offsite fabrication palette complements the external setting – methods to create a sustainable building the building wrapped in zinc, creating a that sits gently within its context. Designed striking environment internally and by architects Hawkins\Brown, the 25 metre, externally for users and spectators alike. six-lane competition-standard pool includes a multipurpose teaching and events space, New beginnings as well as a panoramic view connecting the Hawkins\Brown architects were appointed users with the surrounding woodland. in 2011 to undertake the masterplan for Freemen’s School is a co-educational the school. Phase one was the design and private school for day and boarding pupils, delivery of the new music block and situated in Ashtead Park. Founded in 1854 boarding accommodation, which was in Brixton by the Corporation of London, completed in 2014. its original purpose was to educate orphans The swimming pool marks the second of the ‘Freemen of the City.’ phase, and further phases move onto the Having moved to Ashtead in 1926, the large, Grade II listed main house, a new school is now set in 57 acres of parkland playground, and enhancements to the in the heart of Surrey. As part of a landscaping of the school grounds. masterplan which included the renovation This was not always the plan, however, of several buildings across the school, the as Adam Cossey, partner at the firm, architects have created a new facility that explains: “The masterplan originally had blends well with this historic property, four phases; the boarding accommodation matching the site’s educational prestige and music school was to be phase one, the and natural beauty. main house and dining area phase two, Mole Valley District Council granted three was going to be the provision of an outline planning permission for the energy centre and a swimming pool, and masterplan in 2011. The new pool was a phase four was going to be landscaping for key part of the application, replacing its the entire campus.” former iteration. Although originally He continues: “However, the fire in their planned for a later phase, priorities shifted existing pool area, which was very close to when the old pool was destroyed by a fire the main house, catalysed the school to All photographs © Jack Hobhouse in 2014. move on with the development of the
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14 CITY OF LONDON FREEMEN’S SCHOOL POOL, ASHTEAD, SURREY
swimming pool faster than planned, and so conservation officer. that became phase two.” “On paper, the conversation with the Following this change, along with a new planning department seemed challenging, headmaster coming in, the masterplan was but after taking both the conservation revisited: “The priority for the school was officer and the chief planner around the to replace the swimming pool as soon as building post completion, they were possible. This provided an opportunity to delighted with it.” re-evaluate the proposed location within The sloping gradient on one side of the original masterplan and to consolidate the site gave the architects “a fantastic the school’s sports facilities.” opportunity to effectively give the pool an Another factor in the move was access. ‘upper ground’ and ‘lower ground,’” says “If you’ve got a swimming gala you Cossey. “By extending the pool at lower Even if they’re just visiting, want to move vehicle traffic away from ground level, we were able to have the academic heart, and encourage wrap-around extended glazing on the they can really understand more pedestrianisation.” north-east side of the building, producing Working on a sensitive site, the an amazing view from the pool to the the structure – it’s a very architects and school had to think mature ancient oak woodland.” honest building carefully about how to integrate the pool Also, on the upper level, and tying in
Adam Cossey, partner, Hawkins\Brown into the landscape once it was relocated. with the main entrance on the upper The building is positioned to minimise its ground where the property increases in impact upon the landscape and its height, they included an event space and visibility from the school’s main house. A classroom that overlooks the lower level of partially submerged lower ground floor the pool. nestles the building into the landscape, while hand formed standing seam cladding Inside & out in a dark copper colour responds to Inside the finished building, the architects historic features of the main house, designed a clear circulation, from the main addressing issues raised by both entrance space and reception area on the the local planning authority and the upper level, following through to the
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CITY OF LONDON FREEMEN’S SCHOOL POOL, ASHTEAD, SURREY 15
classroom and event space. Views from both the event reception and event space into the pool are framed by deep window seats, along with blinds to achieve visual separation if necessary. A staircase leads down towards the pool, with doors on one side leading to the changing rooms and then the pool, and another door which leads into the spectator seating area. Glazing has been used around all four walls to flood the structure with light. “When it came to daylighting, we had to be cautious,” says Cossey, however. “We didn’t want glare on the water surface, because that would impede competition swimming.” The south facing glazing has an opaque finish, so there’s no chance of any direct sunlight onto the water. “What we can have, however, is indirect sunlight, i.e. from the north east facing elevations. We’ve got floor to ceiling glass on the lower level, and that allows plenty of daylight into the building.” On the upper levels, glazing wraps the event space, as well as the building’s main reception area. Swimming pools are frequently heavily serviced and environmentally controlled buildings. The final design of the Freemen’s School pool was developed to remain relatively free of services and the associated clutter. All of the environmental control systems, as well as the water treatment plant, are located around the perimeter of a subterranean base, which at its centre houses the pool itself. To introduce airflow into the hall, This provided an opportunity to discreet slots are located in the floor r beneath the glazing, reducing the condensation risk and evaporative heat loss from the pool. The design achieved a BREEAM Very Good rating – the building’s carbon emissions are reduced by 10 per cent thanks to roof PVs. Further carbon savings are planned later in the project, with the next phase of works on the main house to include a CHP energy centre that will utilise the pool as a heat sink. Environmentally-conscious products
have been specified such as Foamglas insulation, which is made of recycled glass. To minimise the building’s impact on the landscape, the swimming pool’s lower ground floor is partially submerged. This ‘beds’ the structure to some degree into the surrounding scenery, and preserves a large number of the existing trees, with the highest point of the gently pitched roof identifying the main entrance.
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16 CITY OF LONDON FREEMEN’S SCHOOL POOL, ASHTEAD, SURREY
A box of two triangles understand how the building has been put The pool has an interesting geometry with together. Even if they’re just visiting, slightly uneven elevations and a roof they can really understand the structure.” comprised of two triangular zinc sections. He adds: Structurally, it is a very honest It resembles a rectangular box which has building.” been slightly squashed at two corners and A softwood spruce is used throughout – folded along its top. The ridge junction in the CLT panels and glulam beams – between the two triangles runs diagonally which, as Cossey says, “ties in nicely with across the space, creating an offset, the surrounding woodland.” The elements dynamic rhythm externally and internally, were formed offsite, with all panels, beams expressed in the CLT ‘ribs’ that hold up and columns prefabricated by Wiehag in the structure. Austria, then assembled on site. The whole Adam explains how the building’s form superstructure was erected in just under was developed during the design process: two weeks. “We began with the end requirements of Cossey says CLT is being used the buildings. Then, we took a rectangle increasingly on a wide range of projects: and extruded it, and you’ve got quite a “People are starting to see the potential of conventional box, we then simply pushed CLT. A little over a decade ago it was a down two adjacent corners of that box, and method of construction that was widely picked up the remaining two corners.” disregarded in the UK, whereas today A standing seam zinc cladding in a dark contractors are increasingly suggesting this copper colour was chosen to cover the as the principal method of construction.” building’s unconventional exterior, with BIM software helped optimise the We have been truly seams forming vertical ribs which are process. “Using BIM technology we can intended to help the structure blend into generate 3D models with relative ease,” impressed by the swift the landscape. Another reason standing says Cossey. “This allows us to create a construction of the pool, seam cladding was used is because it is a very complex geometry, which can be more traditional material, responding to imaged on a computer, then sent straight and how it fits in the key features of the school’s main house. to factory to be manufactured.” woodland space and Off-site timber Collaboration complements the school Led by contractor Gilbert-Ash, the Cossey notes the “fantastically as a whole construction of the pool is centred around collaborative” experience between the a glulam portal frame braced with CLT client, design team and contractor. He Roland Martin, headmaster, Freemen’s School panels. The use of engineered timber continues: “Where there were challenges, provides a fast, efficient, carbon neutral they were dealt with swiftly. From day one, method of construction that provides both there was a very positive, can-do mentality. structure and internal finish. It was an absolute pleasure to work with The all-timber construction also has a everyone involved.” number of advantages in dealing with the Roland Martin, headmaster of the challenges of a pool environment – it is school, gave a glowing testimonial on the resilient, a thermal insulator and corrosion finished building: “We are overwhelmed resistant. On site, the erection of the by the beauty and quality of the new glulam portal frame and cross-laminated swimming pool – it is a fantastic new asset timber walls and roof took just over three for the school and the local community. weeks. This allowed the detailed design “We were impressed by the swift PROJECT FACTFILE and full construction of the building to be construction of the pool, and how it fits in Architect: Hawkins\Brown delivered in one year. the woodland space and complements the school as a whole.” Structural engineer: Eckersley The natural internal surface of the structural timber roof and walls is left It is not often that fires are a blessing in O’Callaghan exposed, and has been stained white. disguise, but it appears to be the case here, Services: Skelly and Couch Here, the material acts as a complemen- with the school now having a striking Contractor: Gilbert-Ash tary feature to the external setting and architectural asset for its students. Landscape designer: BD Landscape helps to create a special environment to Relocated to its proper location as one of Transport engineer: Motion swim in. the school’s sports facilities, and taking Ecology advisor: Aspect This is enhanced by the structurally advantage of, as well as enhancing, its woodland location, it’s not hard to see Arboriculturalist: TreeLine expressive roof geometry with its series of shifting glulam frames, the result being a why it has picked up RIBA South East and BREEAM assessor: SRL visually dynamic space. national awards. Lucky students and Project management: Pick Everard Cossey comments: “The design visitors will be able to ‘swim among the allows students and spectators to really trees’ for decades to come.
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BUILDING PROJECTS POMPEJUS TOWER HALSTEREN, THE NETHERLANDS Keeping an eye on the past
Architect RO&AD’s timber watchtower project in the Netherlands engaged the community in innovative ways to generate a new enthusiasm for the area’s rich history. Sébastien Reed reports
onstruction of the defensive West at the middle of the dyke line, overseen by Brabant Water Line was started in the fort towards Bergen op Zoom to the C1627 by the Dutch states of Zeeland south and Steenbergen to the north. and South Holland as a series of forts, Pompejus Tower, taking its name from the protecting the then main water navigation first commander of the fort, rises 34 metres from Middelburg to Dordrecht against above the surrounding land, and 26 metres attack from the Spanish Armada. Over the above its immediate foundations, the centuries, the Line has repeatedly come difference made up by the fort’s banks under attack from foreign aggressors. Fort from which the tower protrudes. de Roovere north of Bergen op Zoom and The steel-framed structure is enveloped in originally located near the water before land modified timber, and leans at a sharp 60 reclamation, was largest of the forts. degree angle towards the outer edges of the Over the decades, it fell into major fort, inverting the slopes and reflecting the disrepair, to the point that it was almost angles of the banks beneath. Formally, the completely hidden, until 2010 when local tower loosely resembles the shape of a authorities initiated a gradual project of triangular prism, wider at its base, tapering regeneration. Starting by re-excavating towards its upper extremity. canals and trenches to restore the fort’s The brief simply required “a watchtower frontiers, the programme has switched to that can see the waterline – that was the developing playfully symbolic architecture only condition,” Kil explains. Its generic across the site to celebrate its past. nature gave the architects freedom to throw Pompejus Tower in Halsteren is the latest ideas around. “It had to be more than that,” addition – a seemingly gravity-defying says Kil. RO&AD devised a provision that watchtower with extra functions built-in. weaves an open-air theatre and visitor RO&AD’s involvement in the project centre into the scheme. “We saw the emerged from its local connections, as potential of Fort de Roovere being a base INSPIRED BY NATURE founder and architect Ad Kil recalls: “I’d for local theatre groups and building A Voronoi pattern emphasising radial growth from ‘seed points’ outwards was used on the exterior just finished a small job on the then mayor’s connection with the cities nearby.” house, and she asked me to make up some The two outward-facing facade sketches for a watch tower and a bridge for elevations are clad in timber panels, plus a the site. We then slowly got involved.” third inner side – host to a series of Since then, the practice has secured observation platforms at incremental the role of resident architect on the fort, heights – left open. A central doorway at with enviable creative freedom over ground-level provides access to a visitor future additions. centre nestled into the base of the tower, while another doorway one level up leads Functional growth to storage facilities for theatre groups Fort de Roovere was an important focal coming to perform at the fort. point in the landscape for the Dutch. A square of concrete slabs at the foot of Separating saltwater and freshwater, it was the tower’s open elevation functions as a
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20 POMPEJUS TOWER, HALSTEREN, THE NETHERLANDS
A SUBMERGED BRIDGE theatre stage which is observable from each has undergone Accsys Group’s proprietary Constructed before the adjacent tower and using the of the platforms ahead. Multiple sets of acetylation process, whereby planks of the same modified timber is a submerged ‘Moses Bridge’ timber stairs within the tower double up as wood are placed into a pressurised tank of benches at the lower levels, and provide acetic anhydride (high-strength vinegar) and The timber and steel vertical access to each of the observation are, essentially, pickled. The result is a platforms both to watch theatre non-toxic softwood with structural structure leans at a 60 productions, and at the top level – and properties which rival and exceed even degree angle towards the echoing the ancient fort’s original purpose, tropical hardwoods. Acetylation changes to watch the waterline. the free hydroxyls within the wood into outer edges of the fort, acetyl groups. When the free hydroxyl inverting the slopes and Timber rationale group is transformed to an acetyl group, the Explaining why timber was used as the ability of the wood to absorb water is reflecting the angles of primary material for the tower, Kil says: greatly reduced, rendering the wood more the banks beneath “The original fort was built from sand, dimensionally stable and extremely durable, which is soft but durable at the same time. making it much more resilient to water, and We wanted to replicate that, and use a softer less susceptible to rot; a crucial factor given material for the tower. Plus, all of the the Dutch climate’s perennial wind and rain. historical military buildings were made from “Tropical hardwoods were the only wood.” There was also the desire to align other choice, really,” explains Kil, who the tower’s design with the language of the favoured Accoya for its sustainably existing Moses Bridge, located just 150 sourced fast-growing properties. “There metres to the south. was no doubt that we had to work with it,” Like its submerged neighbour, Pompejus says Kil. Tower features Accoya wood throughout – a It was originally intended that the New Zealand grown Radiata Pine which structure be made entirely from wood, but
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to achieve sufficient structural integrity, a was able to raise an additional €70,000 in massive quantity of wood would have been cash for the scheme, as well as more than
required, adding to existing budgetary €300,000 in kind – in the form of expertise concerns, so RO&AD resorted to a from local construction companies, labour, triangular steel framework – regulating costs and building materials. and pleasing the structural engineers, who To foster closer ties with the landscape supported the leaning structure with piles and its history, the architects also wanted driving deep into the banks’ soil. to get the local community involved in the construction process itself, however the Sourcing stakeholders tower’s complexity meant this was an even Initial designs conceived a tower 21 metres greater challenge, as Kil explains: “The high. However, after surveying the site using design was really, really complicated, drones, the architects realised that the but we wanted to make it possible for tower’s scale had to be increased to better see volunteers to screw the tower together. So much more resilient to water, and over trees blocking views of the waterline first, we went to a local school to get them l from ground level. With the extra functions put together a miniature model of the designed-in, and the height requirement tower that we had designed – and they increased, the initial budget of €600,000 was weren’t able to. How could we expect them no longer enough to finance the project. to assemble the real building?” “We needed to get people more connected The fix came to RO&AD almost by to the tower. And we did that by crowd- chance. Kil recounts the story of a trip he funding and building the tower with local and his fellow design partner, Ro Koster, volunteers both companies and individuals,” took to a conference in St. Petersburg, says Kil. Russia to present on various past projects. Using crowdsourcing, the project team Also presenting was Toni Österlund from
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22 POMPEJUS TOWER, HALSTEREN, THE NETHERLANDS
Using a set of algorithms, Geometria transformed the digital 3D model into factory-friendly blueprints which were used to fabricate a full set of flat- packed timber elements with instructions
idea of using a design that “established an aesthetic link with nature”.
From local to global The new tower had its official opening in March 2018, with a christening of the open-air theatre featuring live traditional music, and an audience from the local community unanimous in their praise of the Geometria Architecture, a Finnish digital new, somewhat defiant monument. The PROJECT FACTFILE design practice, discussing a solution that municipality have since been busy curating a they had devised that the RO&AD architects steady programme of performances from Wood: Accoya (acetylated realised could be applied to the construction regional theatre groups for the summer, with Radiata Pine) conundrum at Pompejus Tower. the intention of further cementing the fort’s Location: Fort de Roovere, Using a set of algorithms, Geometria place in the future local cultural scene.
Halsteren, the Netherlands transformed the tower’s digital 3D model Carved into the steps of the tower for all
Wood engineering: Geometria, into factory-friendly blueprints which were to see are the names of individual donors used to fabricate a full set of flat-packed and businesses who contributed help and Finland timber elements with matching instructions, expertise to the project, which is likely to Construction date: December 2017 allowing virtually anyone to assemble them receive visitors from across the globe, in the Opening date: March 2018 by hand. This method not only reduced same way the Moses Bridge has, as Kil Client: Municipality of Bergen labour costs, it inspired a sense of ownership explains. “The bridge is featured in the op Zoom of the tower and a consciousness of the Chinese ‘Top 10 sights to see in the
Builder: Adviesbureau Lüning locale’s rich heritage among volunteers. Netherlands’ guide” – leading to significant
Contractors: Berghbouw, De Kok Part of the tower’s complexity rests in the numbers of Chinese tourists coming to combination of a steel frame made up of Halsteren each year. Bouwgroep, De News Soffers triangles overlaid by timber cladding panels The family of additions at Fort de Roovere Carpentry: VKP Bouw forming a ‘Voronoi’ pattern (similar to a continues to grow, with a new timber Cost: €1.4m giraffe’s spots). The fragmented design made entrance bridge currently under construction for components which could more easily be which will recreate the bridge access of the manufactured, shipped and mounted original defences. Kil says that, compared together by unskilled volunteers. The pattern with its counterparts, “this one won’t be a obscures the triangular framework beneath, special thing – just a nice wooden bridge.” signalling timber as the key material, and However modest it is, with sensitive slits between the facade panels naturally placement into its historical context and the illuminate the tower’s interior while allowing architects’ embracing of innovative and users to observe the surrounding scenery inclusive methods, it’s sure to be a key from varying heights. component of the ongoing success of this These panels are glazed at the levels of the site. That success is largely down to visitor centre and storage area, shielding the carefully-conceived timber buildings interiors from the weather. As well as the re-energising a community’s connection with
more practical benefits, Kil also liked the their built environment, and its past.
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Going with the grain
Here, Gregg Wright of Reliance Veneer explains how the demand for decorative timbers combined with modern manufacturing techniques not only makes environmental sense, but can also enhance design
ave you ever looked at a beautiful piece of furniture and wondered Hhow the distinctive patterns and figuring repeats are achieved, chances are it’s through the use of wood veneer. Veneer is typically produced from the highest quality woods available and although production methods have advanced the basic technique has been used for thousands of years. Many people perceive solid wood to be of higher quality than a product made using veneered panels, but veneered panels have many benefits over solid timber which can be exceptionally heavy, can expand and contract with moisture changes in the air, and even warp if the surrounding conditions are extreme enough. By contrast, manmade panels have wood fibres and glue crossing in so many directions that the
panels are able to remain stable in some of
the harshest conditions. The use of wood veneer in conjunction with the advancements in laminated and fibre panels, such as MDF or plywood, give architects and designers exceptional Veneer is typically produced from the highest quality creative opportunities. As well as being an environmentally sound choice, reducing the woods available, and although production methods
demand on natural wood resources and have advanced the basic technique has been used helping to limit deforestation, use of veneer for thousands of years also makes sound economic sense, allowing designers to enhance furniture with unusual or exotic woods, the use of which would be prohibitively expensive in their solid form. species often show more colour variation Currently there are in excess of 120 and the texture can be more course and natural species available for veneer brittle than the equivalent American species. production in Europe. Timber is a natural Veneer logs have to be carefully selected for resource and as such, no two logs are quality, as manufacturing is an expensive identical, and even within the same species, and exacting process. logs will vary in grain pattern, colour and In Europe and the Americas, veneer is markings. There are many environmental typically cut into three standard thicknesses factors that will determine the suitability of depending on the application for which it logs for veneer production. Weather will be used, most commonly 0.6 mm with patterns in Europe are different to those only about 16 species being commercially in North America and this gives rise to available thicker. Timbers cut more than different grain structures. European timber 2.5 mm thick are normally classified as
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There are truly endless possibilities when
choosing natural wood veneer
sawn lumber rather than veneer. This involves taking leaves of veneer In order to reveal different grain patterns where the grain pattern, colour tone, logs can be sliced in a number of different width and grain structure vary and ways; crown or flat cut, quarter cut, rift, joining them producing a planked, more and rotary cut. Unless rotary cut, veneer rustic look. leaves are often relatively narrow, to cover As trends and fashions evolve, large area. The leaves are matched and veneer once thought of as traditional or joined to form larger sheets called layons. old fashioned, such as oak, sycamore There are many different ways the leaves and beech can be transformed and can be matched using the grain pattern to brought up to date using natural or your advantage, some creating unique chemical dyes. Almost any type of wood effects and designs. can be transformed into almost any Book matching is a traditional method colour or tone imaginable. This enables of matching the veneers by turning over the production of veneers for specific every other leaf, mirroring the leaf adjacent requirements and can provide a consistent to it. Using this method, it is possible to uniform colour. create the most amazing ‘star bursts’ on The dyeing process combined with circular table tops or a pleasing match modern technology means that it is now across wall panelling. possible to engineer veneers to replicate rare Slip matching is much a more natural species that are becoming less contemporary method, as each leaf commercially available, and consequently of veneer remains facing the same increasingly expensive. direction and is jointed next to each There are truly endless possibilities when other to create an asymmetrical but choosing natural wood veneer. uniform pattern. Random matching is possibly the A leading UK wood veneer specialist, Gregg most natural of all the matching methods. Wright is sales director at Reliance
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25 The membrane method Adam Ford and John Mellor of Protect Membranes discuss how to achieve low U-values using membrane technology with low emissivity
he use of timber in construction is now seen as a key route to address Tthe UK’s housing shortage. The Government’s target of 300,000 homes has recently been increased to 340,000 properties to be built in England alone, annually until 2031, to keep on track with demand, according to a 2018 report commissioned by The National Housing Federation. With greater emphasis on meeting this shortfall using alternative construction methods, offsite timber frame manufacture is increasingly seen as a proven method to reduce build programmes and improve cost efficiencies, and, with a precision in design that can be controlled within factory conditions, is currently timber frame panel construction and is a ABOVE the fastest paced sector within UK good way to achieve these objectives. Protect TF InterFoil used in a timber frame wall housebuilding. Construction of timber construction with cavity trays, mineral wool insulation, and internal/external reflective membranes buildings is set to top 60,000 units in 2018, How can the challenge be up from around 52,000 in 2016. overcome with product BELOW specification? Protect TF InterFoil insulating breather membrane What is the challenge? The thermal efficiency of the structure with reflective technology Set against the backdrop of high demand, must be optimised so that low U-values the need for efficient manufacture and can be achieved for each construction maximisation of build space to maintain element to meet the low Notional Dwelling affordability, today’s specifier has to specification requirements. Taking the wall ensure that materials for timber frame construction as an example, the use of construction can meet fabric energy internal breather membranes within the efficiency requirements by delivering low timber frame panel facing two still airspace overall U-values for the structure. cavities either side of the insulation, Current Building Regulations Part L1A can deliver added thermal benefits when set upper limit U-values for each key used with a reflective, vapour permeable construction element (roofs, walls and breather membrane fitted on the outer face floors) as well as airtightness requirements of the sheathing board on the cold side within a structure. As the drive for energy of the construction and a reflective air efficiency continues, the Regulations also and vapour control layer (AVCL) on the detail a Notional Dwelling specification, warm side. which is more onerous and demanding in This combination of products ensures terms of U-values. In the case of a wall, at thermal efficiency if installed with the least a 40 per cent improvement against the reflective surfaces facing into the cavities, upper limit value is required. With the need reducing the insulation needed within a to minimise energy loss from a property timber frame panel while still achieving to lower the environmental impact, the low U-values. This could mean a reduction architect needs to consider innovative ways in the thickness of rigid, high density PIR to design a dwelling to ensure the notional insulation boards or a move to fibrous or specification is met yet is affordable to the EPS insulation without impacting on the end client. wall’s footprint, thereby maximising land Using low emissivity, reflective membrane space and affordability, yet delivering technology with insulating properties strong thermal performance. Designing air within the wall structure is ideally suited to spaces within a timber frame wall panel
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Low emissivity, reflective membrane technology is The correct use of internal ideally suited to timber panel construction and external reflective membranes will effectively block infrared radiation and increase the thermal performance of the airspace, allowing low target U-values to be met
enables developers to meet stringent targets without impacting on the timber frame construction process or significantly increasing the cost of manufacture. To the owner and occupier, the long term integrity of the AVCL and the internal/external breather membranes will ensure that the full design benefits of a thermally efficient envelope are achieved and ultimately enhanced due to the use of reflective technology.
How does a low emissivity cavity work? When using reflective membrane technology, the use of high purity, solid aluminium foil on the surface ensures the membrane forms a radiant barrier when facing at least a 20 mm unventilated airspace within a wall construction. This creates a low emissivity cavity, which significantly reduces heat loss and raises the thermal resistance of the airspace when fixed as per standard timber frame/stud practice and rafter centres. The correct use of internal and external reflective membranes will effectively block infrared radiation and increase the thermal performance of the airspace, allowing low target U-values to be met.
How can manufacturers help? To ensure that the right product is used appropriately within a timber frame panel to provide the required performance, an experienced manufacturer should be consulted – one which offers a full range of wall construction membranes and can ensure a solution based approach. Some manufacturers offer a free U-value calculation and condensation risk analysis service using membranes as part of the build-up to assist specifiers with their overall design.
Adam Ford is head of technical and John Mellor is product manager at Protect Membranes
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The timber revolution
Sarah Harding of Accsys Group reports on how the UK is experiencing a revolution in timber in architecture, as designers and specifiers increasingly embrace the material’s combination of beauty and environmental advantages
unning earlier this year at the Roca London Gallery, ‘Timber Rising: RVertical Visions for the Cities of Tomorrow’ presented an intriguing glimpse into the future of architectural timber solutions. With engaging and in-depth discussions from industry-leading experts throughout the public exhibition, topics such as ‘Forests and Sustainable Cities’ and ‘A Revolution in Construction: Hand in Hand with Nature’ were explored in depth. The panellists – Dr Layla McCay (Centre of Urban Design and Mental Health), Michael Ramage (Centre for Natural Material Innovation at The University of Cambridge), Kevin Flanagan (PLP Architecture) and Elina Grigoriou (Grigoriou Interiors) – have all utilised cross laminated timber (CLT) extensively in their latest projects and research.
Urban practicality combines with aesthetic beauty Commenting on the context of urban environmental impact of this timber can be densification and the associated need to assessed at all stages of its life cycle, from build upwards, Clare Farrow, co-curator of cradle to grave. the exhibition, pinpointed a key issue: “New luxury towers built of concrete, Industry comments steel and glass present exciting and Kevin Flanagan, partner at PLP Architects, symbolic visions of this future, but there is is just one of the many who has recognised also a flip-side. The problem is that cities the outstanding potential that timber can already account for 75 per cent of global offer. He has designed a conceptual timber pollution and consumption of skyscraper at London’s Barbican (also non-renewable resources. In the UK for discussed on page 6 of this supplement), example, the energy consumed in the which was originally intended to be construction and operation of the built provocative, to test both public and environment accounts for almost half of industry reaction. the country's carbon dioxide emissions.” At the event, Kevin Flanagan discussed Timber offers a direct solution to the key construction benefits: “Timber this problem; its carbon credentials are is very light and extremely easy to unparalleled; it is five times lighter than manoeuvre and because of this, structures concrete; and its thermal properties make can be built inside a factory and then it an ideal material for both interior and shipped to site in ready-to-assemble exterior applications. In particular, components, meaning much shorter build modified timber provides compelling times on-site.” environmental advantages over Furthermore, due to its lightness, non-renewable carbon-intensive materials timber can also be used to add to existing such as plastics, steel and concrete. The structures, which may be of paramount
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The environmental impact of this timber can be assessed at all stages of its life cycle, from cradle to grave
importance in an era where overcrowding Green of MGA (Michael Green is becoming an increasing issue. With Architecture) – truly resonated with the newfound vertical layering possibilities, themes of the evening’s conversation. architects may now be looking at “Buildings of late have become adding density to existing structures increasingly sculptural in form, largely instead of requiring new land. This is a driven by an aesthetic preference. In direct benefit of a recent building building nature, beauty is driven by natural forces. code provision that allows for greater In living organisms, beauty and form are soil load-bearing of old foundations not an accident but rather an evolutionary once compacted. means to propagate and survive. The shape Flanagan enthused about the future of a tree’s branch is not a rectilinear form, potential: “Within the next five to 10 instead it has grown to satisfy the complex years, it is extremely likely that there will structural needs of supporting its leaves, actually be someone who wants to build managing wind and reaching for daylight. one of these. Our clients are wanting a The branches’ fibres align and thicken timber structure because it has a special where needed, they slim down where not. appeal to the market that they are going “Buildings of the future will use these after and, in this, the final look of a same principles to make forms driven by building can be very market-driven.” pure structural need, using less material In this context Flanagan remarked how while creative sculptural forms with true “products like Accoya wood open up a engineering meaning. Only then will new world of cladding possibilities – as it architecture truly evolve.” has been modified to protect against water It would seem that architecture is now ingress and other elements.” It is truly in the midst of such an evolution. manufactured using an acetylation process As heard in the panel discussion, it is so that even when it is cut or jointed, the true that increasingly more architects, ability of the wood’s cell walls to absorb interior designers and psychologists are water is reduced by approximately 80 per recognising the potential and, indeed, the cent. This structural change greatly importance of this material. In creating improves the wood’s dimensional stability highly functional masterpieces all over the and results in a stronger, more durable world which will allow people to live and product while reducing coating work more freely and happily, they are maintenance requirements, making it an enabling people to experience the world ideal solution for cladding applications. through a different medium. Throughout the exhibition, quotes adorned the walls of the Roca Gallery in Sarah Harding is head of corporate praise of timber and the progress it has marketing & communications at the made. One in particular – from Michael Accsys Group
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The most sustainable
material of them all
Sean Parnaby of West Port says that the timber industry is gradually winning the war against misconceptions about what he claims is not only the oldest, but the best fenestration material
here’s a growing awareness that But they’re false. A unit’s energy timber isn’t the expensive, efficiency is determined by the glass, not the Tmaintenance-heavy material many frame – and far from being the greenest people think it is – and that its poor option available; PVCu is actually the worst reputation in some quarters has nothing to polluter among window materials. do with timber itself, but stems instead Making a PVCu window pumps 160 kg from the cheap and shoddy mass-produced more carbon dioxide into the atmosphere wood windows of the mid-20th century. than making a timber one does. And But one of the most stubborn timber recycled PVCu windows can contain lead, myths concerns sustainability. Many people cadmium and mercury, all of which are still incorrectly assume timber windows and released as toxic gases when exposed to doors are bad for the environment, but extreme heat, making them highly that’s not true. Timber, when it’s ethically dangerous in fires. sourced, is the greenest fenestration Many people associate timber with material of them all. deforestation – people irresponsibly cutting Increasingly, you hear claims that PVCu down sections of forest, and never replacing is the most eco-friendly and thermally the trees that are removed. But ethical efficient fenestration option on the market – timber is a different phenomenon entirely. understandable given growing public Sustainable timber products come from interest in minimising their environmental well-managed forests, where new trees are impact, and ever-rising heating bills. planted to replace those that are harvested.
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Sustainable timber products come from well-managed forests, where new trees are planted to replace those that are harvested
Planting new trees means that even more CO2 is stored, making sustainable timber products better than carbon neutral. Academics from Heriot Watt University, renowned worldwide for its construction expertise, conducted a comprehensive Life-Cycle Analysis on a variety of timber windows and compared them with PVCu alternatives. They found that using timber to make windows could make ‘a significant contribution to low-carbon building’. This is for two key reasons. The first is that timber itself is a low-carbon material, and the second is that timber offers low thermal transmittance, meaning timber windows offer excellent thermal efficiency and allow homeowners to use less energy to heat their homes. Wood was also found to have ‘significantly lower’ environmental impact than PVCu alternatives. In fact, all the wood windows tested as part of the study were concluded to have negative global warming potential and be carbon negative over their entire 60-year average lifespan. These outstanding ecological credentials are reflected in the fact that the Building Research Establishment’s Green Guide rates wood windows as A or A+ for their minimal environmental impact. Timber is also highly durable, with some well-made wooden structures lasting for centuries. It also helps to meet increasingly strict government regulations aimed at reducing the construction sector’s environmental impact. With timber, you don’t just ensure you meet today’s legislative requirements, you future-proof your project against measures that could be introduced in future, and increase your chances of getting through the planning process. In fact, timber is without a doubt one of the most environmentally friendly, high performance building materials available today and for the future.
Sean Parnaby is managing director of West Port
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Bespoke, traditional timber windows The Sash Window Workshop recently carried out work on a period property in Hertfordshire, manufacturing and installing timber windows. The company manufacture windows and doors at their workshops in Berkshire, allowing them to ensure the new joinery meets the high standards they expect. The materials are chosen to give the best possible performance, combining minimum maintenance with maximum lifespan. They have over 20 years’ experience replacing and repairing timber windows and doors across London and the South. [email protected]
Connecting Cross-Laminated Timber Osmo revives aged wood with power gel To support the growing use of cross-laminated timber (CLT) in the Osmo UK brings aged wood back to life UK and Europe, connector manufacturer Simpson Strong-Tie has with its powerful cleaning agent, Osmo released an updated version of its ‘Connectors for CLT’ catalogue. Wood Reviver Power Gel. This product has Featuring a host of new products including heavy duty angle brackets, been especially developed to restore hold-down connectors and structural screws, this edition represents exterior wood, including wooden decking, a complete set of solutions for the assembly of CLT buildings, as well timber cladding and garden furniture, as steel and chemical mortar products designed specifically to connect back to its original colour and character. the entire structure to concrete. To further support the design Made from environmentally friendly and and construction of CLT structures, Simpson Strong-Tie also has a biodegradable ingredients, it is free from harmful solvents, chlorine team of engineers based at its manufacturing plant in Tamworth, compounds, amines and harmful odours. One coat is sufficient to offering technical support and assistance. The new brochure can be revive external wood back to its natural colour and appearance. downloaded from the Simpson Strong-Tie UK website. www.osmouk.com 01827 255600 www.strongtie.co.uk
PYC Group’s most ambitious project Speedy building with CaberShieldPlus In 2016, PYC Group started planning the Norbord’s flooring product, CaberShieldPlus, most ambitious project they’d done; a new is being used by Sylva Design & Build offsite manufacturing facility and Passivhaus Solutions at Graven Hill, Bicester where they (designed) offices in Welshpool, Wales. Two are creating new affordable homes. Sylva years later, The House Building Factory and Design & Build Solutions, who offer low-risk offices are fully operational. The main design sustainable turnkey home solutions, used challenges for the offices were heating CaberShieldPlus on their timber frame methods and overheating risks. The timber frame structure is heavily fast-track build project. Norbord’s tough P5 insulated with Warmcel, so the decrement delay is as good as it gets, chipboard flooring has a permanent waterproof coating on both sides. and with Welsh temperatures rising to 32oC, the upstairs office CaberShieldPlus is designed with the ever-changing and unpredictable averages 25oC, downstairs 22oC; not too bad at all. British weather in mind. www.pycgroup.co.uk www.norbord.co.uk
Artisan Panel doors for luxury homes Piveteaubois launch HEXAPLI Specialist door manufacturer, Ahmarra have When the 10,000m2, €15 million plant supplied bespoke panel doors for a number of comes on stream in September it will be striking high-end residential properties from the first integrated, large-scale cross their Artisan Panel Door Collection. The Artisan laminated timber (CLT) production range has been designed specifically for operation on French soil, with start-up architects, developers and interior designers output of 50,000m3 a year and capacity working in the luxury residential sector and to go up to 100,000m3. HEXAPLI, from Piveteaubois, is available in offers a wide choice of door and panel designs Pine, Douglas Fir and Spruce in three to nine-ply variants. Floor and and additional joinery components. Proud to fly wall panels come in max 3.5m wide and 16m long. They can be the flag for British craftsmanship, the Artisan Panel Door Collection treated to UC2 against insects and fungi, or, where specified supplied offers the very best quality in terms of design and materials. in UC3.2 sapfree Douglas fir or UC4 autoclaved pine. www.ahmarra.co.uk [email protected] www.piveteaubois.com
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Multi-million pound development project puts best foot forward with anti-slip decking
£140 million development to create a next generation shopping and leisure Apark in Northamptonshire is using JB Antislip Plus Smooth from Marley Eternit to provide a durable and effective external anti-slip surface for visitors. Rushden Lakes, at Nene Valley in Northamptonshire, opened in Summer 2017, and offers over 400,000 sq.ft of new retail and restaurant accommodation, together with leisure activities which are all set against the backdrop of a lake. The unique project, which comprises a 30-acre development, will also link up four existing nature reserves, identified as Sites of Special Scientific Interest (SSSI), to create the Nene Wetlands, a one mile square natural space for visitors and wildlife to enjoy. As part of the project, more than 500,000 sq.ft of JB Antislip Plus Smooth decking was used at the retail park development, creating a linear length of around 40km. Gary Wilburn, director of design and standard for the retail and leisure experience, but furthermore, meet the wider objective sustainability at HPW Architecture, which and as such, we required a decking solution of the development project to ensure led the design and development of the which would not only deliver enduring we used the highest quality specialised masterplan for the 244-acre site, explains antislip properties, but one which would materials throughout.” why, when selecting a decking solution to also seamlessly fit in with the wider The timber decking boards are specifically meet the bespoke needs of the project, JB natural surroundings. designed to provide a durable and effective Antislip Plus Smooth, was the obvious choice. “Having used JB Antislip Plus Smooth external anti-slip surface to minimise He says: “The unique nature of the Rushden previously, we were already reassured that any risk of slipping – even in adverse Lakes development is setting an entirely new the product could meet our bespoke needs weather conditions. JB Antislip Plus uses a unique formula of resin-based aggregate inserts, which are injected into the deck board grooves. For the smooth boards required by this project, grooves are specially machined into the boards to receive the inserts. They are treated to either Use Class 3 (MicroPro®) or Use Class 4 (Naturewood®) to protect the decking and suit the project requirements. Emily Dix, Marketing Executive at Marley Eternit, adds: “For a project, such as Rushden Lakes, where huge numbers of visitors are expected, JB Antislip Plus Smooth decking is an ideal solution, as it offers anti-slip properties which exceed HSL guidelines, but also seamlessly blends with the surrounding environment, making it the perfect choice for retail and conservation areas alike.”
01283 722588 www.marleyeternit.co.uk/decking
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Design Flexibility & Performance from Scotframe
® al-U-Therm PLUS wall panels Denwell Cottage achieve 0.08 W/m2K – probably the Vbest U-value wall in the world. Couple this with Scotframe’s expertise & track record and the sky really is the limit when it comes to design of buildings that tick all the boxes on your clients’ wish lists. Key to achieving this extraordinary performance is that the insulation is injected in off-site, quality-controlled factory conditions. The foam expands into every nook and cranny, providing a best-in-class BR443 U-value correction factor of zero. As well as excellent thermal insulation performance, details are available to minimise thermal bridging and give excellent airtight fabric levels. The Scotframe Val-U-Therm® building system was originally launched in 2011 and has been used in over 8,500 homes with an excellent track record. A UK market leader in full cost-effective way for architects to hit energy Rocking Horse Nursery at the University of timber frame packages for new housing and efficiency, air permeability and other Aberdeen, which caters for 78 pre-school commercial projects, Scotframe exclusively environmental targets. It offers a fit-and- children. achieved an air tightness of offers the Val-U-Therm PLUS® closed panel forget, future-proof solution, whatever level 0.475 ACH. building system. This is accepted by financial of environmental specifications are required Hence Scotframe homes and buildings are institutions, NHBC, Premier Guarantee and – for example, ‘A’ rated Energy Performance warm and draught-proof in winter, cool and Checkmate – the panels have a 60-year Certificates, PassivHaus or the highest levels well ventilated in summer, healthy for all the minimum service life. of energy saving and carbon neutrality. family and enjoy remarkably low energy Because it’s a hybrid of the best aspects of The patented Val-U-Therm PLUS® is bills. Scotframe Val-U-Therm PLUS® allows SIPS and timber frame technology, coupled also inherently sustainable due to careful the construction of typical family homes that with the latest advances in material science, it sourcing of raw materials with a minimal can cost less than £95 a year to heat. offers much flexibility and innovation in environmental impact. Scotframe’s timber is The great news is that building to these the design and build process. The unique sourced from FSC and PEFC sustainably high standards is not necessarily more combination of design opportunities includes: managed forests and the insulation in Val-U- expensive or time consuming using Scotframe •Can be used for walls, roofs and floors Therm PLUS® panels is based on renewable Val-U-Therm PLUS ®. Edinburgh Napier •All types of design and architecture, even vegetable oil, has zero ozone depletion University compared the cost per square curved walls and roofs potential and is CFC, HFC and HCFC-free metre of superstructure using 10 different •Can be thermally engineered to perform with a Global Warming Potential of less than building systems. as an optimum combination 5. This means it has a BRE Green Guide Scotframe Val-U-Therm® cost £1092 when •Unrestricted elevational treatments – A/A+ Rating – the same as straw bales built to PassivHaus standards, whilst the brick, stone, render, cladding, tile, or sheep wool yet is hydrophobic offering other nine systems ranged from £711 to timber, etc. flood mitigation. £1138 when built only to existing Building •All interior finishes and treatments From the UK’s first PassivHaus for rent Regulations. It took 65 days to build a •Large-span roofs with vaulted ceilings, (which won a Green Apple Award) to Scotframe home to PassivHaus standards; the if required examples that significantly exceed the other 26 homes ranged from 49 to 126 days •Dramatic open-plan layouts offering PassivHaus standard, Scotframe has to build, again only to Building Regulations. lifestyle flexibility been leading the way using Val-U-Therm® So, if you are looking to design a dream •Extensive glazed features and technology in energy efficient building for home or superlative building – think uninterrupted roof-space living areas many years. Scotframe Val-U-Therm PLUS®. •BBA accredited building system, including The Maryville PassivHaus delivered a total Scotframe Timber Engineering and Val-U- in-fill panels in other building systems primary energy demand of 69 kWh/m2a Therm are proud to be part of the Saint Couple this with its exceptional thermal (exceeding the PassivHaus requirement of Gobain Group of Companies. performance and sustainability, Val-U-Therm 120 kWh/m2a). This ‘Fabric First’ approach PLUS® provides a straightforward and is also suitable for commercial buildings – the 01467 624 440 www.scotframe.co.uk
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