The Future of Sustainable Construction

Over the last decade a renaissance in structural timber architecture has taken place with the development of new building systems and design strategies, elevating wood to a rival of concrete and steel construction. Issues surrounding this and more were discussed at the recent Solid Wood Solutions conference and exhibition.

The Oculus building at the University of Warwick formed the magnificent backdrop for the recent Solid Wood Solutions event which featured the UK’s principal engineered timber buildings together with presentations from leading academics who are at the forefront of research in cross laminated timber (CLT), laminated veneered lumber (LVL) and glue laminated timber (glulam).

We are faced with two major issues of our time – climate change and a soaring population. Before us we have immense construction challenges whilst mitigating the environmental impact for a variety of building types. The UK is steeped in conventional construction and for some, it is hard to envisage a future in a different direction. 
Robert Hairstans, Head of The Centre for Offsite Construction and Innovative Structures at Edinburgh Napier University, kicked off proceedings. In his presentation, ‘Mass Timber: an Introduction to Solid Laminate Timber Systems’, Robert offered an international perspective, highlighting the growth of engineered timber manufacturers across Europe to meet the increase in demand.
He discussed how Napier students are encouraged to see the value of mass timber beyond the environmental context and in addition, consider the social and economic benefits, combined with the value and ‘adaptability proposition’. Delivering consistency of process, improved quality and enhanced predictability, means mass timber systems deliver great benefits to the built environment, but it goes beyond that. As offsite systems, solid wood solutions promote a better construction culture, facilitating a safer and cleaner working environment, offering job security for local labour and economic viability.

Robert concluded by highlighting some of the barriers to uptake, which are generated from a lack of understanding of mass timber’s benefits combined with sectoral resistance to change, which are impinging on progress. To overcome these barriers Robert called for greater collaboration between industry, government, trade organisations and academia.  

Neil Eaton, Director of Berman Guedes Stretton – the architects behind The Oculus, with its outstanding roof featuring massive glulam arches – presented a case study on the design and construction journey of the building and described how they created a new civic landmark for the University of Warwick. 

By arranging the structure with a sequence of new striking acoustically excellent lecture theatres, together with teaching and amenity spaces, the University has been totally transformed and modernised. A new public front entrance leads to the triple-height foyer spaces with spectacular views over the surrounding landscape. The £15m project was funded by a grant from the HEFCE, and philanthropic donations and is designed to be BREEAM ‘Excellent’. 

The architects’ approach was to design the internal teaching spaces from the ‘inside out’, looking at the acoustic and theatrical function as the major drivers, whilst addressing the ‘outside in’, through a focus on civic presence and its urban context close to Warwick Art Centre. Neil said the best approach is to consider engineered timber as a pallet of materials and play to the individual system’s strength, to create a lightweight buildings with excellent visual appeal, low embodied carbon which minimises the environmental impact, whilst also considering human wellbeing. 

Timber architecture is more fashionable than ever before and is a trend that has major potential for the future of building design and development. This was clearly demonstrated by David Lomax, Senior Associate, Waugh Thistleton Architects. 

Tall timber skyscrapers are becoming an international phenomenon. By using engineered timber as a construction material for residential developments, nature can re-enter urban spaces.  A highlight of the conference programme – David presented a case study featuring the award winning Dalston Lane project, which has been making global headlines. This high-density, low-carbon mixed-use scheme in East London is thought to be the world’s largest CLT structure in terms of volume. David enthused about the benefits of CLT stating – ‘it even smells nicer’. He described the design process as a book of decisions and how CLT, as a robust yet lightweight material did not negatively impact on the underground infrastructure such as HS1 and Cross Rail – permitting extra storeys, delivering a better return on investment for their client, Regal Homes.
Thinking beyond the panelised nature of CLT – modular CLT construction was the focus of the presentation from Gavin White, Director of Ramboll. Gavin considered future challenges with a retiring workforce and the UK’s impending exit from the EU and the impact this could have on migrant workers. Gavin stressed the urgency of the situation – time is running out and there is a pressing need to improve productivity to help resolve the housing crisis. Modular CLT houses, such as those Ramboll are developing with Stora Enso for Swan Housing Association are a progressive option. Modular CLT construction can be used in any sector where there is standardisation.
Gavin White stated: “Offsite construction using CLT is only in its infancy, but it has so many potential benefits that we see this form of construction becoming more and more prevalent. It is up to the industry to maintain the architectural interest when designing with modular units – a challenge which I am sure we will excel at to help solve the housing crisis.”

Heyne Tillett Steel have been providing early stage options to office developers for timber construction, alongside steel and concrete. Although some have been reluctant, Associate, Kelly Harrison, presented some case studies where they have chosen timber, mainly on refurbishments as more storeys can be justified on existing foundations. Main issues tend to arise from deep structural zones in addition to services dropping below the beams rather than through them. In her presentation Kelly considered how to improve this without spending large amounts in fabrication. 

“We’ve been looking at using the CLT compositely with the glulam beam via inclined screws, to reduce the overall structural depth,” said Kelly. “Initial testing has given no failure to the screws and a tensile failure in the glulam above the calculated failure load. When deflections are plotted against load the results are much improved than the beam only calculation, equating to the results you would calculate for a beam 20% deeper than that used. Parallel research in New Zealand has indicated that full composite action can be achieved by 40 inclined screw fixings on a 6m beam, but the calculation of effective width of the top flange is key, which depends on the specification of the CLT. We intend to continue our testing using their finding on the effective width calculation and assess the effect of using less screws. We hope that our research will inspire the industry to start to use this approach as standard and for a future version of the Eurocode to include a method for calculation for use by the wider industry.”

Technical Director for Buro Happold, Jonathan Roynon discussed the benefits of hybrid timber structures. He advocates that timber should be considered as a palette of materials and viewed on an equal basis to all other construction materials. Benefits of various structural timber systems should be taken into account and used to their full advantage, such as the lightweight nature, longer span capability and low embedded carbon. By taking a holistic approach, each material ought to be selected for its particular benefit and by combining the best solutions, as hybrid timber systems can achieve the optimum aesthetic and performance, as well as minimising the environmental impact.
Dyson is name primarily associated with vacuum cleaners and electrical appliances but the entrepreneur, Sir James Dyson has turned his attention to developing the next generation of engineers. The Dyson Institute of Engineering and Technology is unlike any other educational establishment – it is for those with a passion for solving problems and a fascination for how things work.

Max Garcia, Design and Engineering Manager for Carbon Dynamic – who design and manufacture beautiful timber modular buildings – enthusiastically presented an inspiring case study on the Dyson Student Village. Designed by Wilkinson Eyre, Carbon Dynamic recently delivered the prototype, the first of 78 cross laminated volumetric modules to be manufactured.  The volumetric modules were developed using the same prototype approach as Dyson used to develop their technological products: cutting-edge DfMA engineering was combined with a 1:1 loading test. In this way, the buildability of the connection details for the three-storey module stack with cantilevers was tested and optimised to maximise efficiency on the building site.

Austrian timber construction specialist Wiehag is constantly pushing the boundaries of what can be done with timber. This time with a project to build the largest and most complex timber roof ever built in Scotland. Wiehag, who hit the headlines for their massive glulam gridshell roof for the Canary Wharf Crossrail station, has now completed a 200m long glulam timber roof for the prestigious Macallan Distillery in Scotland. John Spittle of Wiehag detailed the design and construction challenges. Located in the Scottish Highlands the new distillery is partly inserted into the landscape and features an undulating green roof. This unique design is reference to the region’s mountainous topography and acts to preserve and enhance the unique landscape.

The roof itself is not really curved but based on a triangulated 3m matrix. Its complex geometry was modelled using parametric software to ensure stability and load-bearing capacity. Austrian timber specialist Wiehag, converted this geometry into 1800 individual glulam beams and 2,500 triangular timber elements that make up the roof’s surface. As no two components of the roof are alike, they were numbered and assembled individually.

Other presentations focused on inspiring projects which have featured in previous issues of the Structural Timber Magazine, including ZÜBLIN Timber’s impressive Maggie’s Oldham – the renowned centre providing practical and emotional support for people living with cancer. Daniel Kreissig presented a case study on the world’s first building made from hardwood cross laminated timber – this pioneering use of engineered tulipwood is a trailblazer for future CLT adoption.

The challenges that faced the Blackdale Student Residences project team were not insignificant. Nic Clark, Managing Director for KLH UK detailed how the specialist subcontractor delivered the project on time, within budget and to such a high standard of design and construction. This development has proven that when the client, designers and contractors work together, any challenge can be overcome and great things can be achieved.

Using BIM Level 2, the ‘one team‘approach with early involvement of KLH lead to a cost-effective solution. The project team collaborated from the outset, fully co-ordinating and clash detecting the CLT superstructure and maximising the benefits of 3D logistics modelling. Nic stressed that the mass customisation approach is a viable alternative to standardisation.

Giancarlo Torpiano, structural engineer for Arup presented an excellent case study on the Warner Stand at Lords Cricket Ground. The unique dramatic fan-shaped timber and fabric roof supported by cantilevered glulam beams makes a dramatic statement befitting this iconic sporting arena. The elegant stand roof features the first use of American White Oak beams of this scale in Europe.

The Solid Wood Solutions programme featured a range of case studies of completed projects, but Fernando Perez, from Smith and Wallwork Engineers, shared the vision for the proposed 300m high Oakwood Timber Tower 2 (The Lodge) – which will provide a mix of functions to create a vibrant new area of the City of London. This is another project that has grabbed headlines across the world. 

The intension is to create new WELL Certified office space, a first for the region. The WELL Building Standard® is the world’s first building standard focused exclusively on human health and wellness. It marries best practices in design and construction with evidence-based medical and scientific research plus it harnesses the built environment as a vehicle to support human health and wellbeing. The building will also contain high quality residential space and numerous shared amenities to support the community. 
The Oakwood Tower 2 is an attempt to discover the wider possibilities of the aesthetics of wooden structures. It is recognised anecdotally that people respond in a positive way to exposed wood. While there is no direct evidence that people distinguish between structural and non-structural wood in this regard, it is hard not to feel that exposure to the working material is rather more interesting, and more authentic, than exposure to purely decorative timber finishes.

Solid Wood Solutions appeals to a wide range of construction professionals and is relevant to all those with an interest in future developments in offsite construction. Solid Wood Solutions will be back in 2019 and next year there are plans to take this event to another level. Keep an eye on developments at www.solidwoodsolutions.co.uk

Share this content