- Area
- Greater London
- Postcode district
- SM5
- Nation
- England
- Guide price
- Priced after survey
- Survey
- Free for installation enquiries
Heat loss survey for Carshalton homes
Every property in Carshalton is different, so the design starts from measurements rather than a rule of thumb. That keeps the system the right size and the running costs predictable.
Houses in Carshalton built in different eras can need very different heat pump sizes, which is why each is calculated room by room. Design outdoor temperatures for Carshalton and the wider Greater London come from local cold-weather data, not a national average.
Every heat pump we quote starts with a room-by-room heat loss survey, free with installation enquiries and also available as a stand-alone report.
- Landlords comparing properties before deciding where to switch first
- Homes with an existing heat pump that seems undersized or expensive to run
- Anyone getting a heat pump quote, as the first step
What's included
- Radiator schedule with any upgrades needed for each room
- Written results in your quote, or a stand-alone report if you order one
- Electrical supply and network operator notes
- Hot water cylinder sizing for your household
- Room-by-room heat loss calculation using the MCS method
Homeowners in Carshalton thinking about insulation work can use the survey to see how it would change their heat pump size.
Grants and rules for heat pumps in England
In England the Boiler Upgrade Scheme gives £7,500 towards an air source heat pump (£9,000 if it replaces oil or LPG, from 21 July 2026 to 31 March 2027), and since 28 April 2026 a valid EPC is no longer needed. The grant is applied for by the MCS-certified installer and shown as a deduction on your Carshalton quote.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Since 29 May 2025, permitted development in England allows up to two air source heat pumps on a house, each up to 1.5 m³, with no blanket 1 m boundary rule — the installation must still meet the MCS planning standards, including the noise check. Listed buildings, flats and some conservation-area positions need extra consent, which we check at survey.
Guide prices for heat loss surveys in Carshalton
The ranges below are typical installed prices for homes in Greater London, including VAT. A survey sets the exact figure, because two similar-looking houses in Carshalton can need quite different radiators and pipework.
| Survey | Guide price |
|---|---|
| Home survey and heat loss calculation with an installation quote | Free |
| Stand-alone heat loss survey and report | £170–£450 |
Inc VAT. A stand-alone report is for homeowners who want the design without an installation quote.
Designing for Carshalton's winters
Carshalton sees roughly 7 hours 51 minutes of daylight in late December against 16 hours 37 minutes in June. Milder southern winters suit heat pumps well, though the system is still sized for a cold snap rather than an average day.
How installation works in Carshalton
- Start online with a guide price or call us.
- A home survey in Carshalton gives us the room-by-room heat loss.
- Your written quote sets out the design, the price and the grant position where you live.
- Installation is booked for dates that suit you; most homes take 2–4 days on site.
- After commissioning you get a handover of the controls and settings, plus the certificates.
Heat loss surveys in Carshalton: questions
Do I need new radiators for a heat pump in Carshalton?
Often some, not all. Heat pumps run best at lower water temperatures, so rooms with small radiators may need larger ones. The survey of your Carshalton home gives a room-by-room list.
How long does a heat pump survey take in Carshalton?
A home survey in Carshalton usually takes one to two hours. The surveyor measures every heated room, checks windows, walls and radiators, and looks at where the outdoor unit and cylinder can go.
Do you cover Sutton as well as Carshalton?
Yes. We arrange surveys and installation in Sutton, which is about a mile west of Carshalton, and across Greater London.
Can I use the heat loss report to get other quotes?
Yes. A stand-alone heat loss report is yours to use, including sharing it with other installers so their quotes are based on the same figures. Comparing quotes like for like makes it easier to see differences in equipment, radiator upgrades and workmanship terms. The report states the assumptions used wherever construction could not be confirmed.
Why can't you size the heat pump from my boiler?
Boilers are often much larger than a home's real heat loss, because they are sized for fast hot water and quick warm-ups. Matching a heat pump to the boiler's output usually means an oversized unit that costs more and switches on and off too often. A room-by-room calculation finds the actual heat demand, which is what the heat pump needs to meet.