Heat pump new installation in a self-build or new home

This service is for self-builds, custom builds, conversions of barns or commercial buildings into homes, large extensions with their own heating, and whole-house refurbishments where the heating, emitters and pipework are all being replaced. If you are replacing a working gas or oil boiler in a house you live in and keeping most of the radiators, the page on replacing old heating with a heat pump is the better fit.

The advantage of a new installation is timing. An installer brought in before the floor screed goes down can specify underfloor heating circuits at the right spacing, route the primary pipework the short way and leave a plant space big enough for the cylinder, buffer or expansion vessels and controls. Brought in after the plasterers, the same installer is working around decisions that were made without them.

In England, Approved Document L says that a newly installed wet heating system, or one fully replaced including the appliance, emitters and pipework, should be sized so the whole system can heat the home at or below the maximum flow temperature the guidance sets. For a heat pump that is not a hurdle but the design target, and most installers aim lower still, because every degree less improves efficiency.

The same document asks for heat pumps to be sized from a proper heat loss calculation to meet the full heating load at the design condition, without relying on a built-in electric heater to make up the difference. On a new build that calculation uses the actual U-values and airtightness targets from your plans, so share the SAP calculation or energy statement with the installer as soon as you have it.

Underfloor heating is the natural partner on ground floors, especially under a screed. Upstairs, oversized radiators or low-temperature fan convectors are common. Room-by-room control is expected: thermostatic control in each heated room or zone, and weather compensation or internal temperature control on the heat pump itself.

• heat loss calculation based on the drawings and specified U-values
• emitter schedule: underfloor circuits, pipe spacing and radiator sizes per room
• design flow temperature and the expected seasonal performance
• plant room or cupboard layout: cylinder, controls, buffer if needed, service access
• outdoor unit position, condensate drainage and the planning check
• electrical supply and the network operator notification

Source: gov.uk

The Boiler Upgrade Scheme in England and Wales is built around replacing fossil fuel heating, and most new build properties are not eligible. A new build that a developer is still building does not qualify. A self-build does qualify if you or the original owner built it, or paid a builder to build it, and it has never been owned by a business or organisation; your installer may ask for proof such as the title deeds. There is no biomass grant for self-builds.

Because the installer applies on your behalf and must install and commission within 120 days of the application, the timing on a building site matters. Talk to the installer about when to apply, so the grant does not lapse while you wait for the roof or the screed.

The zero rate of VAT for heat pumps applies to installations in residential accommodation. On a new dwelling, VAT on the construction work follows its own rules, which your builder and accountant should confirm.

Source: gov.uk

The Future Homes and Buildings Standards are due to come into force in England, subject to transitional provisions. They require new homes to be built with low-carbon heating and add a requirement for on-site renewable electricity. A self-build that gets its building control approval before the change may be treated under the current rules; ask your building control body which version applies to your project.

Wales, Scotland and Northern Ireland set their own building standards. In Scotland, check the current building standards with your local authority's building standards service before designing the heating.

Describe the project stage, the size of the house and whether you have drawings or an energy statement. Once your phone number and email address are confirmed, the request is offered without your name or contact details to heat pump installers covering your area. The first installer to buy it is the only one who gets it; it pays Offrano, and you pay nothing.

We email you that installer's name, address and phone number before they see yours. There is no promise that an installer takes every request, and you are free to ask other installers as well. Offrano checks that buyers are registered businesses, not their design work, so look up the MCS certificate number yourself and ask for an example design from a similar build.