Heat Pumps
Shape Architecture brings its expertise in the sustainable upgrade of existing houses to all its projects. We can advise on simple and cost-effective measures. In addition, we have well established expertise in sustainable technology, from solar photovoltaics to heat pumps and solar thermal panels.
How Does a Heat Pump Work?
A heat pump transfers heat rather than generating it through combustion. It extracts latent heat from the air, ground or water outside the building and upgrades it to a higher temperature suitable for heating and hot water. This process is achieved using a refrigerant cycle powered by electricity.
Even when external temperatures are low, useful heat energy can still be extracted. The system then compresses this energy to increase its temperature before distributing it through underfloor heating, radiators or a hot water cylinder. As a result, heat pumps can achieve efficiencies significantly greater than traditional gas boilers.
Advantages of a Heat Pump
The primary advantage of a heat pump is its efficiency. For every unit of electricity consumed, multiple units of heat can be delivered to the home. This reduces operational carbon emissions and, when paired with renewable electricity, can significantly lower a property’s environmental impact.
Heat pumps also remove the need for on-site combustion, improving air quality and eliminating reliance on gas. They operate quietly, require relatively low maintenance and can provide both heating and cooling in certain configurations. Over time, as the grid becomes greener, the carbon savings associated with heat pumps will continue to improve.
Why Install a Heat Pump?
Installing a heat pump can futureproof a property as the UK transitions away from fossil fuels. Gas boilers will increasingly be phased out, and planning authorities are encouraging low-carbon heating solutions, particularly in new developments and significant refurbishments. For many of our clients, the motivation is twofold: reducing carbon emissions and improving long-term energy performance. A well-designed heat pump installation can provide stable, consistent heat and work particularly well in homes that have been thoughtfully refurbished.
Heat Pumps and the Fabric Upgrade
It is important to understand that a heat pump performs best when the building fabric is improved. Unlike traditional boilers that operate at high temperatures, heat pumps work most efficiently at lower flow temperatures. This makes insulation and airtightness critical.
Before installing a heat pump, consideration should be given to:
• Upgrading insulation in walls, floors and roofs
• Improving glazing performance
• Addressing thermal bridges
• Enhancing airtightness
Underfloor heating systems are particularly well suited to heat pumps due to their large surface area and lower operating temperatures. In retrofit situations, existing radiators may need to be resized to ensure adequate heat output. The integration of fabric improvements and low-carbon technology should always be considered together as part of a coherent design strategy.
Types of Heat Pump
There are several types of heat pump suitable for residential properties:
Air Source Heat Pumps (ASHP)
The most common type for retrofit projects. These extract heat from the outside air and are relatively straightforward to install. They require external space for the unit and careful positioning to minimise visual and acoustic impact.
Ground Source Heat Pumps (GSHP)
These extract heat from the ground via horizontal trenches or vertical boreholes. They offer excellent efficiency but require sufficient external land or drilling capability.
Water Source Heat Pumps
Less common in urban settings but suitable where access to a suitable water body is available. The appropriate choice depends on site constraints, budget, available space and the overall design strategy.
Is There Grant Funding for Heat Pumps?
The UK Government currently supports the installation of heat pumps through the Boiler Upgrade Scheme (BUS). This provides grant funding towards the cost of installing an air source or ground source heat pump in eligible properties.
Grant levels and eligibility criteria are subject to change, so early review is advisable. As part of our design service, we can advise on the suitability of heat pump installation and guide clients towards appropriate funding pathways.