A week, they say, is a long time in politics, but what a week this has been! So you can be forgiven if you missed Chancellor Philip Hammond’s Spring Statement and in particular his plans to make new homes better for the environment as part of the government’s Clean Growth strategy. The planned introduction of a Future Homes Standard by 2025 will require new-build homes to be future-proofed with low-carbon heating and world-leading energy efficiency, mandating the end of fossil fuel heating systems in new homes from 2025. Though this may have been dismissed in the past as aspirational over recent years, enlightened developers such as First Home who, together with Mecserve, have been working on the design and development of fossil fuel-free, all electric residential developments, have been trying to get closer to low or zero carbon homes.
‘Spreadsheet Phil’ has not ditched his renowned cautiousness, the accelerated decarbonisation of grid electricity over recent years is driving a paradigm shift in the way homes should be designed. However, reducing carbon emissions during operation through design is only part of the solution. The embodied carbon of the building must also be considered. As carbon emissions during operation fall, the role of embodied carbon of the building, in the whole life carbon emissions, becomes more important.
First Home’s solutions for building greener, more economic homes that can also be built more efficiently within significantly less construction time in comparison with traditional developments, is to use Modern Methods of Construction (MMC) and Cross Laminated Timber (CLT) as the main material. Depending on how its end of life is planned, the embodied carbon of CLT could be very low or negative. This is due to carbon sequestration i.e. timber is a renewable material which stores carbon throughout its usable lifespan.
There are other advantages in using MMC in combination of CLT that will reduce carbon emissions during construction further, such as reduced construction time and associated energy use; reduced amount of waste generated on site and also reduction in required transport to and from the site.
Therefore, the total embodied carbon of these developments will be significantly less than that of a traditional development of a similar size and orientation.
For operational energy, Mecserve and First Home have followed the “Fabric First” principles, where the first priority is minimising heat loss through the building fabric by improving the thermal performance the building and reducing the air permeability to the lowest feasible and viable limits. The construction method used enables the development to improve the airtightness significantly while ensuring continuity of insulation which reduces thermal bridging.
Whole-house ventilation systems with high efficiency heat recovery ensures that outside air will be pre-conditioned before it enters the occupied space, thus reducing any heat loss from ventilating the dwelling. The heat demand for each dwellings will be negligible with the internal gains being sufficient to offset the heat losses for most of the year.
The rest of the energy demand from the building will be met by a combination of air source heat pumps and photovoltaic panels. As battery technology improves it is planned to incorporate them into the overall solution.
These solutions are available today and represent a road map to getting closer to a true zero carbon development which also considers the whole life cycle carbon of the buildings i.e. both embodied and operational carbon emissions.
Given the efficiency and the speed advantage of the construction method, and its progressive way of addressing climate change and the need for cutting carbon emissions, the First Home approach may be one solution to the current housing crisis, particularly in London, so why wait until 2025 Chancellor?