July 25, 2021

A potential barrier in the road to reaching net zero carbon targets

The Government’s recent consultation on extending the ban on combustible materials to more building types and lowering the height restriction in England from 18m to 11m closed on 25th May. Andrew Carpenter, Chief Executive of the Structural Timber Association (STA) discusses how this ruling, if adopted, will severely inhibit our ability to decarbonise the UK construction industry.

In late May Roger Harrabin reported on BBC News that the Government is planning to reduce the maximum height of timber framed buildings from six storeys to four to reduce fire risk. Mr Harrabin rightly pointed out that this action would contradict other advice to increase timber construction because trees lock up climate-heating carbon emissions.

But this will not only totally contradict other government advice to reduce carbon emissions but flies in the face of the support that it has shown for offsite manufacturing to deliver the much needed housing –  the most proven of which are timber based systems.

It is clear that the UK is out of step with the approach being taken by leading economies in Europe as evidenced by the actions of President Macron – he has ruled that all new publicly funded buildings in France should be delivered from at least 50% timber or other natural materials by 2022. Another study from Germany’s Potsdam Institute found that a global boom in wood buildings could lock in up to 700m tonnes of carbon a year. And I can only agree with the head of the Committee on Climate Change, Chris Stark when he said: ‘Timber buildings can be tall and safe. Displacing cement, brick and steel with wood means more than double the carbon savings in buildings overall.’

The STA and other timber trade bodies say the Government in England has misunderstood the science behind timber construction. A blanket ban that is not based on building physics, test evidence or scientific facts is seen as a quick fix and as a result, the UK could experience far reaching implications for decades to come. Climate change is not some abstract concept, if not dramatically addressed it will be catastrophic and the biggest crisis of our time. 

The Government’s response to climate change has been to set net zero carbon targets by 2050 but there is no ‘road map’ to navigate this journey if the most sustainable and replenishable of all building products, is potentially banned. With as much as 7% of all global CO2 emissions coming from other less sustainable construction technologies, it is difficult to see how these targets will ever be met if these restrictions come into force.

The blanket banning of products does not address the Hackitt Review findings for more accountability and responsibility of how buildings are constructed. Nor does banning products improve build quality or clarify roles and responsibilities in the decision-making process. I could go on, but the point is made. Height restrictions are not a measurement of safety. Poor design results in inferior and not necessarily safe buildings – regardless of the technology from which they are constructed.

The lack of clarity as to what the ban applies to is creating confusion and the STA and our members firmly believe that any extension to the current 18m restriction should focus on the external cladding and not the structural wall itself. We will only support this height restriction on the proviso that Building Regulations replicate the Scottish model where 18m is still acceptable when supported by evidence of non-combustible cladding and well-designed fire management systems. These views together with robust test evidence has been reflected in the STA’s response to the Ministry of Housing, Communities & Local Government (MHCLG) consultation.