Find out which low impact materials are right for your building project.
We all owe a great deal of thanks to the likes of Greta Thunberg and the millions of children and young adults that have finally started bringing many of us to our senses and waking up to the reality of human induced climate change. Whilst we may not all agree with their methods, Extinction Rebellion have also brought the issue to the front of our minds and forced us to start listening to what climate scientists have been saying for the last 30 years and more.
The atmospheric carbon emissions we’ve been making for the last few hundred years have exponentially increased over the last century and are causing our climate to change. The changes are going to result in the world becoming significantly less hospitable for us unless we drastically change the way we live currently and reduce our carbon emissions, along with the many other gasses that we emit that cause atmospheric warming.
One of the areas that we at Back to Earth have been trying to influence for many years is in construction. By switching construction materials and simplifying designs it is possible to create buildings which are carbon neutral during their construction and then, with the use of renewable energy, carbon neutral during their running.
Many architects are really trying to change the way they work to address this climate concern but are unsure about how to proceed and the lack of familiarity with materials such as wood fibre insulation makes the transition a challenge. These barriers slow the move away from ‘business as usual’ and encourage simple tweaks to existing practices which on paper appear to solve the problem.
Where to start
Firstly, building designs need to improve to reduce heat loss to absolute minimums but still accommodate the hotter summer time temperatures that occur. The obsessive focus on ‘reinventing the wheel’ and coming up with ‘unique’ and ever more extreme designs can have it’s place but should not be at the expense of function and therefore environmental impact.
Large glazed areas look great but lose lots of heat in winter and admit lots of heat in summer, neither of which benefit comfort inside the building. Remember that even triple glazed windows still have 5 times the thermal conductivity of a well insulated wall.
Don’t design using SAP. It is possible to use SAP as a means of just passing the minimum building control thresholds but it is an assessment tool not a design tool and does not necessarily build buildings which are comfortable or healthy. Start from first principles of health and comfort, not what is the bare minimum that can be spent to scrape through the building regulations.
Simplicity in construction is hugely beneficial. It ensures the building is easier to build, produces less waste during construction and also means that it is more likely to achieve the performance targets it was designed to achieve.
Expand your view of cost. Just looking at the construction cost of a building does not give any indication of the actual long term cost and affordability of it. The cost of running the building at comfortable temperatures, with good indoor air quality and all of the other parameters that encompass comfort and health should be factored in. Excluding measures such as airtightness and minimising thermal bridging may prove to be expensive in the longer term.
Overheating is now an issue. With summertime temperatures regularly exceeding 30 degrees celsius, buildings insulated with very cheap, lightweight insulations become prone to overheating. This is not only uncomfortable and stressful for the occupants but can health impacts and also pushes them towards reliance on air conditioning during the summer. This obviously achieves the exact opposite of the original aim of the insulation.
Consider the impact of the materials used and then use more renewable materials. It is easy to design buildings using lots of insulation that look like they will keep the running cost of the building to a minimum but then forget that the insulation may be made from non-recyclable plastics or energy intensive minerals that release lots of carbon dioxide during their manufacture.
A typical house may produce between 50 and 80 tons of carbon dioxide during it’s construction and as this is released in a big ‘carbon burp’ at the beginning of the life of the building. This has a much greater environmental impact than the slow release of carbon dioxide during the lifetime of the building and so carbon neutral construction is an immediate way to minimise the impact of a building.
Timber in construction
Wood is a fantastic construction material for many reasons. It is a good structural material, it has fairly low thermal conductivity, it can be formed into many different products such as wood fibre insulation and importantly, it can be grown and replenished in the timescales that we work around. Wood also absorbs carbon dioxide as it grows and when we build with it we lock this carbon into our buildings.
Locking up carbon in this way is how it is possible to build carbon neutral buildings. This can offset the emissions from the concrete and steel used elsewhere in the building, materials which will always need to be used in some capacity.
Wood fibre insulation also locks up carbon and, on the whole, is either carbon neutral or carbon negative by the time it reaches site. The amount of which depends on what type of product you’re using and where it has come from.
Wood and wood fibre insulation also store lots of heat. This ability to store heat in the structure and the insulation means that buildings can be simply designed but made to stay cool in the summer as well as warm in the winter. Heat can also be stored in the fabric of the building to reduce heating requirements and improve comfort in the spring and autumn when the sun is low and heat gains through windows are high.
Wood and wood fibre insulations are also very good acoustic absorbers too. In areas where housing density is high and where traffic volumes are large, acoustic insulation is very important to reduce stress on occupants. Quietness allows a sense of privacy and relaxation, vital in modern life.
Build with confidence
This is the where we can help. We have nearly 25 years of building experience to draw from and have worked with hundreds of architects to start them down the road towards net zero carbon construction.
Using tried and tested specifications we support architects through the design of new builds and retrofit projects alike. We provide design and detailing guidance to allow a full project specification to be created, one that is simple, practical, thorough and above all, buildable.
Wood fibre insulations can be used in all above-ground areas of new construction and retrofit. They manage moisture very effectively and dry fast, ensuring risk during the construction of timber frame buildings and construction times are minimised.
In conjunction with a timber frame structure the buildings can be carbon neutral or better during their construction.
By switching to these materials it is possible to start addressing the climate emergency immediately and also to build in the necessary resilience for the changes in climate that we are already seeing.