The construction industry gets a bad rap in the UK and, for the most part, we agree with the criticism. There is no doubt that for too long, the industry has had sloped shoulders in carrying responsibility for both loss of life and malpractice on many levels. The Grenfell disaster highlighted the industry’s practice of just shrugging off common sense and tendency to lean on an outdated and a slowmoving legislative system.
However, in recent weeks, we have seen industry journals flooded with demands for change in the industry that are seemingly irreconcilable with each other:
- Construct without damaging the environment
- Produce less waste
- Create jobs
- Reduce on-site costs
- Reduce on-site traffic
- Create homes that are affordable
- Create homes that are warm
- Create homes that are aesthetically pleasing
- Build safe
- Build fast
- Build cheap
- Build NOW
Is there a way of doing it all successfully? Or is there always going to be a compromise? We all know, or are becoming increasingly aware of the benefits of using timber frame construction over ‘traditional’ materials when it comes to the environmental impact, as well as reduced waste on site.
The Climate Change Committee recently assessed that if 270,000 homes were built each year using timber frame, we could triple the amount of carbon captured in UK homes.
CEI-Bois, the pan-European trade body for the timber supply chain, also confirmed its research concluded that waste from a build could be reduced by up to 90% using a timber framed manufacturing method.
So, it seems that we already have our champion for ‘cleaner’ building in the UK. But what of the other demands?
The Psychological ‘problem’
How can we hope to build safe homes, following disasters like Grenfell, using a material that burns? Surely, we should be heading towards stone, concrete and the old bricks and mortar approach? Let’s face it, that’s what the construction industry in the UK is accustomed to. So, it fits with the narrative of ‘let’s not change what we do – we already work with safe materials’, why would anyone swap to materials that are seemingly flammable?
Can you have the best of both worlds? In the US, timber-based buildings are the norm. In fact, since the 1950s not much has changed on that front – even in 2018 a huge 93% of homes were built using timber. It’s the ubiquitous go-to material for many reasons; its malleable nature, ability to flex but still remain strong for minor earthquakes and tornados, and its natural ability to regulate temperature, and therefore save money on heating and cooling are but a few. And yet, there doesn’t seem to be the same level of fear surrounding its safety.
So why not in Europe? With 43% of the EU covered in trees, producing 470 million m3 of sawlogs every year we seemingly have the means and the information needed to make more rounded choices regarding using timber for construction here. With sales of timber homes set to reach £800m in 2020, the industry is definitely moving towards this way of constructing. But what of the fire risks?
With the Grenfell disaster still in our minds (as it must be), the fears around fire safety are for the first time front and centre. For too long, fire safety has been an afterthought and hopefully, following the Hackitt inquiry, the UK construction industry will move forwards in terms of the knowledge and requirements surrounding fire safety. Having said that, the jury remains out on whether the industry will take it upon itself to move before it is pushed.
In the May 2019 Barking fire, a lit barbecue on a balcony is thought to have caused the wooden cladding to catch alight. This caused the government to re-think timber decking and cladding products, and the new legislation, which mandates non-combustible cladding product above a certain height limit has lodged worry in the minds of people when building with wood.
However, if we think about mass timber frame, wood actually remains more structurally sound than concrete or steel at high temperatures. Steel turns to ‘spaghetti’ and the chemical and physical structure of concrete changes completely. In wood the rate of char, which slows the progression of the fire, is predictable so it’s not as simple as just saying wood burns and steel doesn’t.
Similarly, during a project conducted by International Fire magazine, where they mapped fire incidents in timber framed buildings in Sweden between 1998 and 2014, only one fire could be related to the construction material and, as summarised in the report: “Existing statistics thus show a lower rate of fire incidents leading to the intervention of the fire services in the wooden houses, compared with the national average for all apartment buildings.”
So, maybe it’s time to rethink our perceptions of wood. Our environmental saviour that’s quick to build with and reduces waste whilst also remaining structurally safe, regulating temperature inside and providing the fire resistance required – why wouldn’t we use it?
With the correct legislation adhered to, good design, and a hefty helping of common sense, there is no reason why timber cannot be safe in a fire, as proven by extensive research in the Nordic countries and North America. Wood may even be safer than other methods of construction with the optimum choice of fire treatment, profiles and species.
Innovation, driving the use of fire-retardant treated timber as the norm, and a systematic approach to fire safety from the start of a build rather than as an afterthought, will deliver the best of both worlds and achieve all of the requirements mentioned at the top of this article.
This isn’t a case of setting off environmental benefits against reduced safety – there doesn’t have to be a conflict at all, just re-education.