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With changes to the building regulations, heat pumps become a more automatic choice for housing developers

We’ve just held our second ‘Transforming the Housing Technology Mindset’ seminar which saw architects, specifiers, consultants and heating engineers come together to discuss ways of improving our housing stock in the UK.

These have proved very popular and I believe are part of a growing trend in finding more sustainable ways of delivering the quality homes that people need.

Our first, held in December, saw a forthright presentation from our Ecodan ambassador, TV presenter and architect, George Clarke, who called for the industry to “stop building crap homes”, which seemed to resonate with the audience and which he’s written about here.

A major focus was the need for more modular homes, so that quality can be in-built at the factory level, rather than being reliant on the weather on a building site.

This really spells the end of high carbon fuel such as cumbersome oil and expensive LPG

Max Halliwell Max Halliwell Communications Manager

Factory versus field

Whilst a growth in prefabrication is to be encouraged and applauded as a way of changing the way we do things, the reality, at least for the next few years, is that housebuilders will continue to follow the existing model and build new homes ‘out in the field’. 

So what can be done to ensure that these homes are more sustainable and less carbon intensive than before?

Well this is where a change to the building regulations will really make a difference and is the reason why I believe we are about to see a significant growth in the number of renewable heat pump systems, in use in the UK.

Don’t be a SAP

One of the major changes in the Standard Assessment Procedure (SAP) is to significantly reduce the carbon emissions factors for electricity, in reflection of the rapid decarbonisation of the National Grid.

An amendment to the building regulations, known as SAP10, this sees a significant reduction in the related carbon emissions for electric heating, which makes the case for using renewable air source heat pumps much, much stronger.

It sees electricity related carbon emissions reducing from 0.519 kgCO2/kWh to 0.233 kgCO2/kWh, and means heat pumps are now only slightly higher than mains gas (0.210).

This increase in the production of ‘clean’ electricity for the national grid is something we predicted over a decade ago, when we produced our Green Gateway approach to energy use in buildings.

According to an article in CIBSE Journal: “Current SAP assumes that electricity used produces 2.4 times the carbon emissions of mains gas. The 55% reduction in the CO2 emissions factor for electricity means homes heated by direct electric systems will produce virtually the same CO2 emissions as gas, while heat pumps will produce even less.”

The article also quotes acting head of sustainability development at CIBSE, Julie Godefroy, saying that: “‘SAP 10 has aligned the carbon factors with reality, The new carbon factors and distribution losses will change the appraisal of low carbon heating options.”

A heat pump in every new home

SAP calculations are used to assess the energy performance of dwellings in the UK and are a key part of Building Regulations compliance.

When SAP10 comes into force later this year, it will revise the calculations that house builders use and will mean that a heat pump only needs a coefficient of performance (COP) of 1.1 to produce lower carbon emissions than a gas boiler.

The average heat pump is now producing COPs of 2.5 and more so this makes a stronger argument for easy-to-fit, renewable heat pumps over gas, and really spells the end of high carbon fuel such as cumbersome oil and expensive LPG.

That means a potential increase in heat pump sales nearing the 100’s of thousands each year, based on current levels of house building.

Should we see an increase in council building following the removal of the borrowing cap, then this could climb even higher as we try to get near the 300,000 homes that the country is estimated to need each year.

Don’t forget retrofit

Whilst this is great news that will help reduce the energy use in new-build homes, we mustn’t forget the millions of homes that already exist and, once again, this is where heat pumps can play such an important role.

As we see the thermal efficiency of more existing homes improved with better insulation and double or triple glazing, the case for replacing the old heating with a renewable one becomes even stronger.

All-in-all, we are now seeing the start of the renewable revolution with air source heat pumps now ready to step up and deliver reliable, renewable heating to keep the nation warm and reduce the overall carbon footprint of the country.

Max Halliwell is Communications Manager for Mitsubishi Electric's Heating & Ventilation Systems