Timber Development UK study finds mass timber buildings reduce whole-life carbon by 50%; five UK projects demonstrate lower emissions, improved occupant wellbeing

Measuring Mass Timber is a report – free to download – that convincingly demonstrates the many benefits of mass timber.

It examines five different mass timber buildings, of varying type and purpose, in detail; working with the designers to apply rigorous, consistent analysis to each.

The key takeaways are great headlines for mass timber, proving just what a sustainable and healthy material it is:

• A mass timber building typically has less than 50% of the whole-life embodied carbon of a comparable ‘business as usual’ (LETI Band E) building.
• It has 47% less upfront carbon (A1-A5) than a comparable ‘business as usual’ building.
• Mass timber buildings have powerful biogenic storage potential. For example, the five buildings analysed safely store away the carbon equivalent of over 50,000 journeys from London to Glasgow by car.
• Mass timber provides palpable quality of life enhancements. Occupants reported feeling more relaxed and comfortable, with 76% expressing a satisfying reminder of the natural world.

It all goes to show that mass timber offers a decarbonisation solution right now.

A wide range of mass timber buildings

The case studies are all from the UK, and cover education, infrastructure, worship, residential and commercial. The buildings were designed by  practices Architype, Fereday Pollard, Marks Barfield Architects, Tikari Works and Waugh Thistleton Architects.

Each building underwent detailed life cycle analysis, internal environment monitoring and user consultation over the two-year study. The report demonstrates the abundant benefits of mass timber by evidence-led research. The broad range of buildings showcase how these benefits might be maximised across sectors to cut carbon in construction.

“A key takeaway is that mass timber is a readily available solution that can help achieve ambitious embodied carbon targets today, while the quality of life assessment of the case study buildings has revealed them to be healthy places that help people connect with nature.”

Each building underwent detailed life cycle analysis, internal environment monitoring and user consultation over the two-year study. The report demonstrates the abundant benefits of mass timber by evidence-led research. The broad range of buildings showcase how these benefits might be maximised across sectors to cut carbon in construction.

Carbon storage – keeping it locked away

One big advantage in including such a varied range of buildings is that we start to appreciate the different opportunities. For example, Abbey Wood Station, being key infrastructure, has a 120-year stated lifespan: this really brings home just how securely stored away its biogenic carbon is (all 315 tCo2e of it). Similarly, Cambridge Central Mosque, being a religious building, is unlikely to ever be replaced: it stores 1071 tCO2e.

All told, the five buildings analysed store 5,158tCO2e in total. This is the equivalent carbon of building 161 “business as usual” homes; or 396 years of an average British person’s annual emissions; or flying from London to Hong Kong and back 1478 times. The mass timber case studies store three times more carbon than an equivalent area of UK woodland.

And it’s worth remembering that this biogenic carbon storage is not a factor in the low whole-life carbon and embodied carbon figures quoted at the start of this article. Mass timber buildings achieve much lower embodied carbon than ‘business as usual’ buildings before we even consider the biogenic storage.

This is compelling evidence that mass timber is a valuable tool in decarbonisation. The five case study buildings all perform well against standard industry targets for whole-life carbon.

Occupant satisfaction: wood is good

It’s not just about carbon. The report found that mass timber buildings contribute to quality of life – which was evidenced through evaluation of peoples’ experiences in inhabiting/using mass timber buildings across typologies. The communities using the case study buildings self-reported improved aspects of quality of life.

They collectively reported a sense of being reminded of the natural world by the materials. They also stated feeling more relaxed and comfortable in these buildings compared to others. Furthermore, internal monitors measured healthy conditions overall across the buildings.

“We have seen how mass timber supports lower carbon construction today. We have seen how mass timber and biophilia can help people feel more connected to nature, to feel more relaxed and comfortable and to provide healthier internal environments. So let’s accelerate its use responsibly and efficiently, and support sustainable and ethical forestry practices.” – Kat Scott, Report Co-Author