A new-build heat pump is an air-to-water system designed into a home while it is on the drawing board or being built, rather than retrofitted later. Because walls, floors and glazing are being chosen at the same time, heat loss can be calculated from the drawings, and the emitters, pipework and cylinder can be planned for a low flow temperature from day one.
Small developments near South Glamorgan can be designed plot by plot, with heat loss worked out from each house type's drawings. New homes in South Glamorgan designed with underfloor heating downstairs get a low flow temperature that suits a heat pump. Plots in South Glamorgan with tight boundaries benefit from fixing the outdoor unit position before landscaping is finalised.
Who it suits
- Replacement dwellings and major conversions treated as new homes
- Homes designed with underfloor heating on one or more floors
- Small builders and developers working on one-off homes or small groups
- Architects and builders who want a heat loss design from the drawings
Grants and rules for heat pumps in Wales
Homes in South Glamorgan can use the Boiler Upgrade Scheme, which applies in Wales as well as England: £7,500 towards an air source heat pump, or £9,000 when it replaces oil or LPG heating for installations from 21 July 2026 to 31 March 2027. The MCS-certified installer named in your quote applies and deducts the grant.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Wales has its own permitted development rules for air source heat pumps, so we check what applies to your property, including listed building and conservation-area constraints, at the survey.
New-build and self-build heat pumps prices in South Glamorgan
These are guide prices for South Glamorgan, installed and including VAT. Your final price is fixed in a written quote after the survey and depends on the heat loss of the house, the radiators that need changing and where the unit goes.
| Home | Typical size | Installed guide price |
|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,500–£12,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,500–£13,500 |
| 3 bedroom semi or small detached | 6–9 kW | £12,000–£15,500 |
| 4 bedroom detached | 8–12 kW | £14,000–£18,000 |
| 5+ bedroom or larger older house | 11–16 kW | £16,500–£22,500 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning. Most new builds are not eligible for grant funding, so no deduction is shown.
Towns we cover in South Glamorgan
We cover 6 towns in South Glamorgan for new-build and self-build heat pumps. Each links to local guide prices and the grant position for Wales.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Cardiff | CF10 | Penarth | 7 h 50 min |
| Barry | CF62 | Dinas Powys | 7 h 51 min |
| Penarth | CF64 | Dinas Powys | 7 h 50 min |
| Cowbridge | CF71 | Llantwit Major | 7 h 50 min |
| Dinas Powys | CF64 | Penarth | 7 h 50 min |
| Llantwit Major | CF61 | Cowbridge | 7 h 50 min |
New-build and self-build heat pumps questions
Where should the outdoor unit go on a new build?
Somewhere with free airflow, a solid base and drainage, away from bedroom windows and boundaries where possible, and positioned to pass the MCS noise assessment. On a new build this can be planned into the landscaping, such as a side return or screened area near the plant room, which keeps pipe runs short. Planning rules differ by nation, so we check the position at design stage.
Is underfloor heating worth it in a new build?
For many new homes, yes, because underfloor heating runs at low water temperatures that suit a heat pump, and laying pipes during the build is far easier than adding them later. It also frees up wall space. Radiators cost less and respond faster, so some self-builders combine underfloor heating downstairs with radiators upstairs. The design shows the flow temperature each option needs.
Can a self-build get the Boiler Upgrade Scheme grant?
In some cases. In England and Wales the scheme is aimed at existing homes and most new builds are not eligible, but some self-builds can qualify depending on circumstances, so check eligibility before including a grant in your budget. If the scheme can apply, the MCS-certified installer named in your quote handles the application. Scotland and Northern Ireland are outside the scheme.
When do you need to be involved in a new build?
Ideally before the drawings are finalised, so the plant space, outdoor unit position and emitters are agreed with your architect. At the latest, the design should be done before first fix, when pipework goes in under floors and inside walls. Late involvement usually means compromises, such as a cylinder in an awkward space or pipe runs boxed in afterwards.