The decades old practice of using the fabric first approach to improve the energy efficiency performance of our homes is not the only solution to achieving zero carbon goals according to scientists at Oxford University.
Researchers at the Environmental Change Institute (ECI) at the University say we should not assume the regularly adopted fabric first approach which prioritises heat conservation over heat generation is the right one for every home.
We all want to reduce our homes’ heat loss and at the same time achieve a low carbon, sustainable house that’s affordable to heat and maintains healthy comfort conditions. For new builds installing energy saving measure from scratch is patently the best approach: insulation, good windows, airtightness and capturing as much of the sun’s heat as possible all reduce a building’s energy needs.
However, when it comes to retrofitting older homes, one size does not fit all.
Prof Nick Eyre, Emeritus Professor at the ECI, and lead author of Fabric first: is it still the right approach? said:
The imperative to decarbonise buildings completely implies a shift away from fossil fuels for heating. If this is to be done quickly, it challenges the idea of fabric first, where this involves complex and expensive deep retrofit.
In many individual buildings, decarbonisation can be achieved by changing to a zero-carbon fuel, in most cases a heat pump using decarbonised electricity. In some cases, this will be the least-cost approach to decarbonisation; in others, notably where there are lower-cost insulation opportunities, some fabric improvement will still be needed.”
In the article, published in the journal Buildings & Cities, the researchers say that as domestic properties are all different, the journey towards zero carbon emissions needs to be bespoke.
Working alongside Prof Eyre were ECI colleagues; Dr Tina Fawcett, Senior Researcher and Associate Professor; Marina Topouzi, Researcher; Dr Jan Rosenow, Honorary Research Associate; and Kay Jenkinson, Knowledge Exchange Specialist.
Dr Tina Fawcett, Senior Researcher and Associate Professor, added:
Our research suggests taking an ‘understanding first’ approach for individual buildings, taking into account the costs and savings for different building types and conditions, but also the needs of occupants for a comfortable and healthy home.
For the UK as a whole, to get to net zero delivery on time, for many homes the solution will be to put in a heat pump first. We don’t have the time or available workforce to take a universal fabric first approach, and the increased availability of low carbon heating options can offer some buildings a faster and cost-effective way of reducing emissions.”
The researchers highlight that retrofitting fabric first may not be feasible across the whole housing stock on timescales necessary for rapid decarbonisation and could therefore slow housing decarbonisation.
Their study found that in many cases, no additional fabric improvement is needed to decarbonise heating; a heat pump, or other zero-carbon heat supply, will be enough.
Installing heat pumps sooner needn’t mean ignoring other heat saving measures though, and insulation will bring more benefits through reduced electricity usage and lower costs. Good practice in today’s heat pump industry is to install lower-cost fabric insulation measures (if not already present) at the same time as the heat pump.
Prof Eyre added:
Fabric improvement will continue to have an important role. Energy use in buildings with a ‘heat pump only’ retrofit will be higher than if insulation were also improved. Fabric should continue to be prioritised in new buildings and where low-cost insulation measures are available.”
Read the report in full: Fabric first: is it still the right approach?