CTI Blog

CTI Blog - Why Build In Wood?

This article is by Paul Brannen, MEP for the North East England Region. It originally appeared on www.northeastlabour.eu

 

Historically timber has been used to build homes, especially one and two storey buildings.  Taller and larger buildings have been possible with timber frames but above 5 or 6 storeys is rare.

However, relatively new engineered timber products such as Cross Laminated Timber (CLT) and Laminated Veneered Timber (LVL) have the structural strength of steel and concrete, enabling wooden framed buildings to now be built to much taller heights and on a much larger scale.  

These new products have enabled the construction of the world’s tallest wooden building, Tallwood House at Brock Commons East, on the campus of the University of British Columbia in Vancouver, Canada.  It is 53m tall with 18 floors - you can watch it being constructed in under 3 minutes here. 

Wooden buildings even taller than this are currently under construction including the HoHo building in Vienna, Austria which will have 24 floors, see here, and a Japanese company are planning on building the world’s tallest wooden skyscraper.  Other wooden skyscrapers are being built or are planned across the globe.

There are many benefits to be gained from building in engineered wood, including:

 

Speed

Building in wood can see a floor a week being constructed on site, as the wooden panels are constructed off site in factory conditions. This is twice as fast as concrete.  Overall wooden buildings can be up to a third faster to build reducing construction site costs i.e. the hired crane is there for less time.

 

Sustainable

Timber is a renewable and sustainable product when managed and produced in an environmentally friendly way.  Construction timbers, such as CLT, LVL and Glulam, are made with a non-toxic adhesive and can be made with little or no burning of fossil fuels unlike steel, brick and block which all need large amounts of heat to produce and they tend to derive this heat from the energy produced from burning fossil fuels.  The actual chemistry involved in making cement for concrete results in large amounts of CO2 being released. Theoretically this could be captured (Carbon Capture and Storage - CCS) but to date it has not happened.

 

Sequestration of Carbon

While trees are growing they sequestrate carbon from the air. In fact trees could rightly be described as CCS ´machines´. When trees are turned into timber products the timber still continues to sequestrate the carbon for the life time of the wooden product, hence timber is a natural “carbon sink”.

Tall and/or large steel and concrete buildings have large carbon footprints.  Comparable wooden buildings can have a reduced carbon footprint of 60-75% in comparison. 

 

The importance of substituting for steel and concrete

Concrete and steel have large carbon footprints.  One of the primary ingredients in concrete is cement and to make cement you need to heat and grind up limestone or a similar material. In addition to the energy required in the manufacturing process, the U.N calculate approximately 1 ton of carbon dioxide is emitted per ton of cement produced.  As concrete is the second-most consumed substance on the planet, after water, cement production accounts for as much as 8 percent of human-produced carbon dioxide emissions.

Concrete and steel are both heavy to transport involving large numbers of lorries that in turn generate exhaust fumes that contribute to poor air quality especially in our cities and they also burn fossil fuels exacerbating climate change.

Wooden buildings can be five times lighter than a steel and concrete equivalent meaning transport costs both financially and environmentally are reduced. Lorry deliveries to the construction sites where wood is the principal building material can be reduced by 80% because wood is lighter and needs fewer lorries to move it. As wood is lighter this can also reduce the groundwork (foundation) costs.

A 125m high building made from wood could have a 75% lower carbon footprint than one made from steel and concrete.

50% less energy is used to manufacture wooden rather than concrete buildings and only 1% of the energy needed to produce steel.

During construction wooden buildings produce less dust and their construction is quieter, which is good news in urban areas.

Following construction in cold climates the estimated energy consumption and carbon emissions for CLT buildings are 9.9% and 13.2% lower than those of reinforced concrete buildings in view of life-cycle assessment; see here for more information. 

Currently using building methods centered around, concrete, steel, brick and block, the building sector is responsible for 42% of final energy consumption, 35% of total greenhouse gas emissions, 50% of extracted materials and 30% of water consumption in the European Union. Construction and housing have a fundamental role to play in enhancing societal goals for sustainable growth, see here.

 

Health/Ambiance

Wooden interiors deliver a multiple of physiological and psychological benefits including:

- reduced blood pressure, heart rate and stress levels

- improvements to a person’s emotional state and level of self-expression

- improved air quality through humidity moderation.

 

Renovation and Refurbishment

As a light-weighted material that can be processed easily, wood is the ideal material for renovation and refurbishment, allowing high flexibility for inhabitants and users to adjust buildings to specific needs. 

 

Cost; Timber/CLT v concrete/block/steel

A question often posed is whether building in wood is cheaper than building in a material such as concrete. To help answer this question, Building magazine undertook a price comparison in June 2017 and noted:

“We have prepared two detailed cost models, one each for a CLT and concrete design for a seven-storey private residential building. The scheme has been designed with both a timber and concrete solution in mind at the outset, with a structural layout to suit both.

“…the construction cost variance between timber and concrete for this hypothetical scheme is minimal. The higher CLT superstructure costs are offset by the ability to reduce pile quantities because of a lighter frame, hence a saving on substructure. The CLT programme for the frame and upper floors is around 10–15% shorter than the concrete option, resulting in a lower preliminaries cost.”

The cost of wooden buildings can be kept down by pre-fabricating panel sections in factory conditions where they can be made to the millimetre, meaning that there’s little to no waste.  Doors and window apertures can be pre-cut in the factory.  Government figures show about a third of the materials that arrive on a construction site using concrete tend to get sent to landfill resulting in more lorries on the road.

In April 2018 Alinea Consulting produced an influential report that highlighted the advantages of using CLT over concrete. The report, Residential Timber: Cost Model, suggests CLT is a viable alternative and uses two detailed exemplar cost models to demonstrate the point.

Wooden buildings are more energy efficient meaning longer term the owners will both use less energy and pay smaller energy bills.  If the CLT used is thick enough then an energy saving of 14% could occur. This is because wood has a natural thermal efficiency which means timber systems can be more cost effective in constructing energy efficient buildings than concrete, block or bricks.

Additionally, In a recent (July 2018) independent study produced by Rider Levett Bucknall (rlb.com) a comparison was made between the cost of timber frame v masonry build methods in order to determine which is more economical for affordable housing.  The study found "the overall situation ... results in the timber frame solution being more economical to construct" p16.  It was also "quicker".  

 

Fire

But aren’t wooden buildings more prone to hazards and natural disasters?

Buildings made from CLT have no inherent fire risk.  When brought into contact with fire the outer surface of the wood chars and then acts as a very effective insulator for the wood below.  When the heat source is removed the fire goes out. Furthermore, CLT remains more structurally stable when subjected to high temperatures.

See demonstration of an attempt to set fire to CLT with a blow torch in this Economist video on wooden skyscrapers here.

Further, Silvia Melegari wrote in Revolve that CLT buildings, “have the flexibility to handle the world’s strongest earthquakes with no loss of life or structural change”.

 

Who is designing and building big in wood already?

Architects

Waugh and Thistleton, London: http://waughthistleton.com/

White arkitckter, Sweden: http://whitearkitekter.com/project/skelleftea-cultural-centre/

Bob BBL, Norway: https://www.bob.no/

Acton Ostry, Vancouver, Canada: http://www.actonostry.ca/

LEVER, Portland, USA: https://leverarchitecture.com/

 

More Information: Interesting Links and Articles

Videos

What is Cross Laminated Timber?  https://www.youtube.com/watch?v=YuAya0hRjwU

The world’s tallest wooden buildings: https://www.youtube.com/watch?v=v3JqSsc8ZKk

TED talk by architect Michael Green, ‘Why we should build wooden skyscrapers’:  https://www.youtube.com/watch?v=Xi_PD5aZT7Q

 

Articles

Innovative Wood Products Collaborative, ‘Why build with wood?’ http://www.themostnaturalresource.com/why-build-with-wood/

New Statesman, “Why wood is making a comeback in house building”, http://bit.ly/2PEXq4s

Building, ‘Cost model: residential timber’ http://bit.ly/2yPDguQ

Sustainability Open Access Journal, “A Comparison of the Energy Saving and Carbon Reduction Performance between Reinforced Concrete and Cross-Laminated Timber Structures in Residential Buildings in the Severe Cold Region of China” http://www.mdpi.com/2071-1050/9/8/1426

Revolve Magazine, Spring 2018 Issue: https://issuu.com/revolve-magazine/docs/revolve_27_digital

Benefits of Urban Trees, a FAO infographic: http://www.fao.org/3/a-c0024e.pdf

The contribution of wood-based construction materials for leveraging a low carbon building sector in Europe: https://www.sciencedirect.com/science/article/pii/S2210670716305923

Adoption of unconventional approaches in construction: The case of cross-laminated timber: https://www.sciencedirect.com/science/article/pii/S0950061816313514

Cost gap between CLT and concrete is narrowing: https://www.trada.co.uk/news/cost-gap-between-clt-and-concrete-is-narrowing/

Cement Industry Urged to Reduce Invisible Global Emissions http://bit.ly/2OtyYOE

 

[News URL: http://cti-timber.org/content/cti-blog-why-build-wood]

CTI Blog - Timber is set to be a vital, dynamic part of UK industrial future

This blog post is by Roy Wakeman OBE, CTI Chairman

This feature is also included in CTI response to the Industrial Strategy Green Paper

 

Timber; flexible, structurally strong and having the lowest embodied carbon of any commercially available commodity; contributes $600 billion to the global economy around 1% of global total GDP.

The World Bank forecasts the global demand for timber will quadruple by 2050. The timber supply chain is a key part of the manufacturing and construction industries in the UK adding an annual value of over £10 billion to the UK economy. It provides jobs across a wide spectrum of skills, directly employing over 150,000 people across the country (with over 350,000 jobs reliant on timber).

Recognising that skills are critical to productivity, there are currently over 10,000 apprentices currently working towards a woodworking, carpentry or joinery qualification and it is predicted that approximately 4,000 apprentices are required to be recruited each year for the next four to keep up with demand.

The industry is constantly evolving and through the Confederation of Timber Industries (CTI) we are developing our core qualifications to ensure that they embrace latest and future requirements. The supply chain is attracting investment in manufacturing and logistic capacity, developing new products and innovations in a variety of sectors and applications. If this growth is to be maintained in a rapidly changing economic and political environment, we need to work together with Government to ensure the right policy and market frameworks are developed.

The CTI was formed in 2015 to do just this, acting as an umbrella organisation across the Timber supply chain. With the support and leadership of the Timber Trade Federation (TTF), Builders Merchant Federation (BMF), British Woodworking Federation (BWF), and the Structural Timber Association (STA), as well as a network of individual companies and organisations, the CTI is lobbying to put the Timber Industries at the heart of the new industrial strategy.

The CTI will focus on several key themes to influence the development and expansion of the Timber supply chain: Sustainability; Value & Growth; Skills, Jobs and Training; and meeting our Housing needs. In these areas, we will work collaboratively to stimulate growth and productivity, providing pan-supply chain representation across the industry to ensure that timber is not just seen as a vital element of our industrial heritage, but that it remains a vital, dynamic part of our industrial future.

 

[News URL: http://cti-timber.org/content/cti-blog-timber-set-be-vital-dynamic-part-uk-industrial-future]

CTI Blog - CTI launches largest ever survey on skill shortages in timber supply chain

This blog is by Dirk Vennix, CTI Chief Executive

I am really pleased to announce that the Confederation of Timber Industry (CTI) has published the largest employer skills questionnaire ever undertaken in the UK's Timber Industry Supply Chain. The views of businesses on skills and education will be summarised in a policy report to be published in the Spring of 2016. The CTI will present the findings to Government and key stakeholders in order to shape the political agenda on education and skills as indicated in our recently published strategic plan.

As I said in my previous blog about skills the CTI strongly believes that Education and Skills development is critical to ensure that Timber leads the way in 21st Century Construction. On the 23th of September 2015 the CTI network set up a specific working group on this subject involving a range of organisations and companies across the Timber Industry. We agreed that to start with we need to answer some basic questions: where are the skills shortages? Where will the supply come from? What is needed in terms of funding and infrastructure? How do we get the next generation to want a career in the timber sector?

The last major employers’ survey for the timber sector was conducted by Proskills in 2011. We now need up to date research which identifies the current level of skills shortages and gaps in education provision within the whole Timber Industry Supply Chain, from timber traders to timber frame manufacturers and builders’ merchants. It will be distributed to businesses through trade associations, training providers and other interested parties operating in the UK.

The CTI has commissioned Proskills to map current education providers delivering to the sector, highlighting gaps between supply and demand. Similarly, the research will identify areas of strength and excellence offering a catalyst for the engagement of the industry in improving skills, recruitment and training. 

Succession planning for an ageing workforce and gaps in provision are issues which need to be addressed. Few young people decide to choose timber as a career option, as repeatedly outlined by trade organisations, training providers and companies. This issue is exacerbated by the limited offer of further Education courses, apprenticeships and craft qualifications that affects the growth of the whole sector. It is time to turn the page addressing the problem with focused measures.

The launch of the survey represents a great opportunity for the timber industries to express their views about skills needs. Everyone is keen to encourage young people to go for a career in the timber sector. Depending on the outcomes of the survey the CTI could raise the profile of the industry with young people by supporting the launch of new timber related courses as well as helping increase the number of apprenticeships and developing an ambassadorial schools network across the supply chain. But first of all we need to hear your views so please help us to reflect what you need in the workplace by filling in the survey below.

The survey is accessible online or through a printable version, downloadable here.

Deadline for submissions: 5 February 2016