There is an aesthetic, economic and environmental case to opt for timber frame construction, and as construction shifts away from concrete and towards natural construction materials, the latter case will become increasingly essential.
The Future Homes Standard prioritises reducing carbon emissions, with a focus on renewable heating, improved insulation and high-quality, low-carbon construction methods.
In all three cases, timber frames make a significant contribution, and to see why, it is important to explore a descendent of Future Homes Standard and low-carbon housing, in the form of the Passivhaus movement.
What Is Passivhaus?
Passivhaus, which is German for ‘passive house’, is an energy efficiency standard for buildings that are specifically designed to not require a lot of energy to heat or cool.
This voluntary standard in turn ensures that they have a very low carbon footprint, something that is increasingly important as energy efficiency standards focus increasingly on whole-life embodied carbon, or the emissions caused from the harvesting of construction materials to its demolition and disposal.
The particular focus is on passive heating and cooling, where a building is designed in such a way that through careful construction, ventilation and insulation principles, they retain a comfortable and consistent ambient temperature without heavy reliance on air conditioning or central heating.
Where Did It Come From?
The initial interest in passive houses initially came from the United States in the 1970s, as the 1973 Oil Crisis made it clear that a standard of housing that focused on roaring open fires that necessitated poor insulation and a wasteful use of resources was no longer sustainable.
The main focus was superinsulation, where existing houses were retrofitted with significant insulation upgrades, but it set the wheels in motion for a much greater evolution of the same principles.
One of the first major research projects that explored the potential for passive houses was the Saskatchewan Conservation House (SCH), which incorporated timber framing and timber siding into a highly airtight, insulated building which relied on hugely ambitious heat recovery and solar energy systems.
Much of this was the product of necessity; one of the reasons why the oil crises were so devastating was that alternative energy research had been neglected to the point that an average house could not be powered using contemporary solar panels.
This is far less of an issue today, partly because solar panels are much more efficient and affordable, but also because the average energy demand of a home is significantly less, with the SCH proving that it was possible even in particularly variable climates.
The Saskatchewan region has incredible temperature variations, which could reach as high as over 40 degrees Celsius in the height of summer and minus 40 degrees in during the deepest part of midwinter.
Whilst not the first passive house, with several houses being made in Denmark, Massachusetts and Illinois, it proved to be highly influential.
How Does Timber Framing Help With Passive Houses?
The key to success with passive houses is that every design decision and choice of materials needs to focus on airtightness, superinsulation, insulated triple or quadruple glazing and controlled ventilation.
Part of the benefits of timber framing is that it can be prefabricated with airtightness and sealing in mind, which minimises the need for heating at all, and allows for any remaining heating needs to be served with ultra-efficient zero-carbon heating technologies.
Most people who have lived in a timber frame home after living in a less efficiently insulated property note that it feels cool in the summer without feeling cold in winter, providing a best-of-all-possible worlds approach that saves money and provides greater comfort.
Added to this is the whole-life aspect of timber that makes it such an attractive prospect for the construction industry as a whole, not just green construction.
It is renewable, is carbon negative when sustainably sourced and harvested, and is so strong that entire skyscrapers have been made with timber as a primary or only support material.
Beyond this, it also reduces carbon emissions whilst in use; concrete has the worst of all possible worlds by both being polluting in mining and manufacturing and also in its use; the process of mixing concrete inherently releases carbon dioxide.
It also slows down construction, as does brick and mortar buildings, as both need significant time to cure and dry, whilst timber is perfectly designed for efficient prefabrication.
It can reduce construction times significantly, which has a far greater effect on overall building costs and carbon emissions, which in addition to its natural qualities being geared towards Passivhaus construction, make it a vital force in a green construction future.