By Malcolm Thomson, Sales Director, Scotframe.
Sustainable building used to be the exception rather than the rule. However, thanks to shifting client attitudes due in no small part to increased energy prices, together with stricter building regulations across the UK, designers, builders and developers are under more pressure than ever to consider long-term energy efficiency measures right from the outset of their projects.
This is what the timber frame sector has championed for many years – a ‘fabric first’ approach to building design. ‘Fabric first’ simply involves maximising the performance of the building’s external envelope, rather than relying on ‘add-ons’ to improve a building’s energy efficiency and sustainability credentials.
So rather than using things like photovoltaics or energy-saving technology such as smart home gadgets, designers of ‘fabric first’ buildings concentrate instead on maximising air tightness, eliminating thermal bridging, and optimising insulation, solar gain and natural ventilation. Using ‘fabric first’ can lead to significant energy cost savings over a building’s lifetime – it can deliver an overall energy reduction of up to 33 per cent.
One major advantage the ‘fabric first’ approach has over renewable energy systems is that it doesn’t require the occupant of the building to master complicated new tech or adjust their energy consumption habits – the building does all the hard the work for them. Also, a building’s fabric can’t be easily tampered with, so it will continue to perform as intended for decades, essentially ‘future-proofing’ a design as technology advances and more stringent building standards are introduced.
Timber frame lends itself perfectly to a ‘fabric first’ approach, due to its natural energy efficiency – it really is the most environmentally friendly way to build. Wood is effectively a carbon-neutral material, even when you take transportation into account. The amount of energy taken to produce timber components – their “embodied energy” – is much less than that of plastic, steel or concrete alternatives, and in fact structural timber has the lowest overall CO2 cost of any building material.
In Scotland – and indeed most of the rest of the developed world – timber frame is currently the most popular construction method for domestic low-rise properties, and for good reason. By using timber within the fabric of a building you can reduce energy consumption through improved thermal performance, air tightness and better insulation. Timber has a low coefficient of thermal conductivity; requiring less insulation than other materials, such as steel frame, to achieve the same U-value.
It is easier to make a timber frame building airtight than a masonry one, as timber is ideally suited to offsite construction in quality-controlled factory conditions, with its associated benefits of higher quality, increased speed and reduced labour costs. Closed panel building systems, manufactured off-site, are particularly effective in terms of thermal performance, as they have insulation which is injected into the panels and expands to fill every space.
I’m seeing a clear shift in attitudes across the construction industry towards off-site solutions as more and more people begin to fully understand these advantages.
There are numerous other benefits to fabric first. It’s essentially a “fit and forget” approach, so once the building is complete, the job is done. Very little maintenance is required, avoiding the long-term need for regular upkeep and cleaning of renewable tech like solar panels.
Energy efficient, fabric first buildings also have health benefits, because thermal comfort and indoor air quality both play a large part in our health and wellbeing. A fabric first building constructed using timber frame delivers a warm, draft free, comfortable environment. Timber has also been shown to improve indoor air quality by moderating humidity.
It also has a calming influence on a building’s occupants, lowering the human sympathetic nervous system activation and reducing blood pressure and heart rate. According to the Wood for Good campaign, a study conducted in 2010 in an Austrian school compared two timber-built classrooms with two standard classrooms. Children studying in the timber classrooms had significantly lower heart rates, were noticeably more relaxed and performed better.
The construction industry must take sustainability, cost and wellbeing into consideration if it wants to keep clients happy and meet building regulations, so to me, designing using a fabric first approach is a no-brainer. Forget relying on expensive add-ons or assuming occupants will adapt their energy consumption habits – just design it in from the start, and then forget about it.