| 47
attraction is centred on the ‘three S’s’; its sequestration of carbon from the atmosphere, it’s carbon storage and its capacity to substitute higher environmental impact construction materials.
Built by Nature is currently supporting around £1.3bn of building developments. With leading developers, it has also supported production of the Commercial Timber Buildings Guidebook, a good practice and risk mitigation handbook for mass timber office building in the UK.
SECURING INSURANCE FOR TIMBER BUILDING
A further challenge to UK timber building has been securing insurance. Consequently, Built by Nature has also backed production of the Mass Timber Insurance Playbook, a guide on how to secure cover published by the Alliance of Sustainable Building Products and written by insurance professionals.
One construction project the organisation has supported is Phoenix, a “sustainable neighbourhood” in Lewes. The business behind it is Human Nature, which describes itself as a ‘campaigning development company’. The project covers a 7.9ha brownfield site and will comprise nearly 700 dwellings, all timber based.
Human Nature says the development “seeks to turn the imperatives of the climate and natural emergencies into opportunities for better design, better placemaking and ultimately healthier and better living”. In the session on ‘Drivers of Timber Construction’ at the conference, Human Nature’s Russell Tame said that another ‘bottleneck’ in timber construction developments was planning. How the Phoenix project navigated the complexities had attracted a lot of interest. “We’ve had direct enquiries from other landowners, including local authorities in Liverpool, Manchester, Sheffield, Leeds and London,” he said.
He added that Human Nature saw its role as helping drive investment in timber-based building by “increasing the understanding of less informed groups” about its merits. “Some investors and clients are enlightened, others still ask ‘doesn’t it catch fire and can we get insurance?’,” he said.
The company’s head of sustainable construction Andy Tugby said an aim of the Lewes project was to provide a showcase of the possibilities of timber building. “This is no time for business as usual in construction,” he said. “We have to develop climate friendly solutions and commit to exponential sustainability.”
This, he added, wasn’t just a case of using more timber, but using it better and most efficiently, to get the maximum benefit from the resource.
full timber-frame office, but the other two are concrete frame with cross- laminated timber (CLT) decks,” he said. “It’s important to look at other materials to get the right solution for the project, particularly as their producers are now looking to catch up with timber in terms of environmental impact. In a fourth project we’re also evaluating the option of eco-concrete and steel.” The consensus was that commercial timber developments were 3-5% more costly than the equivalent in concrete and steel. However, developers said this was increasingly offset by speed of build and tenants’ positive view of timber building, which led to faster occupancy rates and a quicker return on investment.
EXPLORING TIMBER HYBRID OPTIONS In the same session, Sam Tame of developer Related Argent highlighted timber’s capacity to work with other building products. “Of three of our recent projects, one is a 148,000ft2
In the conference session on ‘Building Confidence in Timber Construction’, Judith Schulz of engineers Arup highlighted the still greater need to demonstrate the fire performance of timber building since the Grenfell Tower fire in London in 2017. It has produced the guidebook ‘Fire Safe Design of Mass Timber Buildings’.
“This looks at the layers of building safety taking a risk-based methodology, ranging from evacuation strategy, to the extent of exposed timber and types of adhesives used in mass timber,” said Ms Schulz. “We hope to support greater uptake of mass timber building, which has been held back by a lack of [technical guidance]. We should also leverage the approaches taken by authorities in other jurisdictions to develop market confidence.”
Architect Andrew Waugh of UK mass timber building pioneers Waugh Thistleton Architects said the objective of the practice’s New Model Building guidebook was also to plug the knowledge gap and increase confidence in timber building in the post Grenfell context. This effectively provides a template for constructing regulatory compliant mass timber buildings under 18m. “It provides 30 generic details for any residential building under this height, each with three choices of product. It’s effectively a check list for contractors, covering everything from fire safety to moisture management,” said Mr Waugh. “If these are adhered to, developers can be sure of receiving approval from the UK National House Building Council.”
SWEDISH PERSPECTIVES
Lending a perspective from Sweden was Carl Bäckstrand of White Arkitekter. He looked at the development of timber- based residential districts in Swedish
construction, going back to the Sundsvall project of 15 years ago. Their success, he said, has been based on close collaboration of academia, urban authorities and the construction business, including architects, engineers and developers.
“It’s been a process of these three branches working together to drive the timber agenda,” he said.
White Arkitekter’s latest project is its biggest to date, the Wood City in Stockholm, which it is working on with Danish design studio Henning Larsen. In fact, the development will be the biggest mass timber construction project in the world so far, comprising 7,000 office spaces, 2,000 homes and covering 250,000m2
. Due for completion in 2027, Mr Bäckstrand
said Wood City builds on the Nordic construction industry’s already extensive experience of such large-scale urban applications of timber construction. That includes in securing finance and insurance. The reluctance of contractors seen in the UK to shift from what is perceived to be ‘conventional’ concrete and steel construction is also not an issue in Sweden. “Such projects are no longer new in Sweden and contractors have developed expertise in working on them,” said Mr Bäckstrand. He also said the Swedish construction sector shared the experience of its UK counterpart, that timber-based buildings achieve faster occupancy and also higher rentals longer term, so helping to recoup the higher initial build cost.
EXTENDING UPWARDS WITH WOOD Increasing capacity of existing buildings with roof top extensions, as mentioned by Mr Walker of Bywater, was the focus of another conference session. Speakers said it was particularly appropriate for urban development, helping towns and cities grow without extending their boundaries – and timber was the ideal material for such projects. Its strength to weight meant that the height of the building could be increased without having to reinforce the existing structure.
It’s becoming such an area of interest that the Dutch have a word for it, ‘optoppen’, or top up building. Moreover, UK timber building specialist engineer Whitby Wood, with a consortium of European partners led by Built by Nature, has now launched the optoppen website on the topic.
Director Kelly Harrison said the objective of the open-source, interactive site was to “enable city planners and asset owners to quickly understand the vertical extension potential of their buildings” using timber and other bio-material construction solutions. ■
www.ttjonline.com | September/October 2024 | TTJ
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105
