Getting the size right matters. An undersized heat pump struggles in cold weather, while an oversized one costs more to buy and can switch on and off frequently, which wastes energy and wears components. Sizing from a rule of thumb, or simply matching the old boiler's output, is a common cause of poorly performing systems. A measured, room-by-room design avoids both problems and shows the reasoning behind every figure.
Houses in Kent built in different eras can need very different heat pump sizes, which is why each is calculated room by room. For Kent homes with extensions or loft conversions, each part of the house is assessed on its own construction. Design outdoor temperatures for Kent and the wider Kent come from local cold-weather data, not a national average.
Who it suits
- Self-builders and architects who need emitter and system sizes early
- Homeowners planning insulation or building work who want to know the effect on heat demand
- Homes with an existing heat pump that seems undersized or expensive to run
- Anyone getting a heat pump quote, as the first step
Grants and rules for heat pumps in England
Homes in Kent can use the Boiler Upgrade Scheme, which takes £7,500 off the cost of an air source heat pump when it replaces fossil-fuel or electric heating. Replacing oil or LPG heating qualifies for £9,000 for installations from 21 July 2026 to 31 March 2027, and air-to-air systems for £2,500. The MCS-certified installer named in your quote applies for the grant and deducts it from the price.
There is no VAT on installing a heat pump anywhere in the UK until 31 March 2027. In England most houses can have an air source heat pump under permitted development, provided the unit meets the MCS noise and siting standards; the old 1 m boundary limit was removed on 29 May 2025. We flag listed buildings, flats and sensitive conservation-area positions at survey.
Heat loss survey prices in Kent
The ranges below are typical installed prices for homes in Kent, including VAT. A survey sets the exact figure, because two similar-looking houses in Kent 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 | £150–£410 |
Inc VAT. A stand-alone report is for homeowners who want the design without an installation quote.
Towns we cover in Kent
We cover 24 towns in Kent for heat loss surveys. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Broadstairs | CT10 | Margate | 7 h 51 min |
| Maidstone | ME16 | Rochester | 7 h 52 min |
| Gillingham | ME7 | Rochester | 7 h 51 min |
| Royal Tunbridge Wells | TN1 | Tonbridge | 7 h 53 min |
| Folkestone | CT20 | Hythe | 7 h 54 min |
| Margate | CT9 | Broadstairs | 7 h 51 min |
| Ashford | TN24 | Tenterden | 7 h 53 min |
| Canterbury | CT1 | Whitstable | 7 h 52 min |
| Sittingbourne | ME10 | Faversham | 7 h 51 min |
| Gravesend | DA11 | Strood | 7 h 50 min |
| Ramsgate | CT11 | Broadstairs | 7 h 51 min |
| Dover | CT17 | Folkestone | 7 h 53 min |
| Tonbridge | TN9 | Royal Tunbridge Wells | 7 h 53 min |
| Strood | ME2 | Rochester | 7 h 51 min |
| Whitstable | CT5 | Herne Bay | 7 h 51 min |
| Deal | CT14 | Sandwich | 7 h 52 min |
| Sevenoaks | TN13 | Westerham | 7 h 52 min |
| Rochester | ME1 | Strood | 7 h 51 min |
| Herne Bay | CT6 | Whitstable | 7 h 51 min |
| Faversham | ME13 | Whitstable | 7 h 51 min |
| Hythe | CT21 | Folkestone | 7 h 54 min |
| Sandwich | CT13 | Deal | 7 h 52 min |
| Tenterden | TN30 | Ashford | 7 h 54 min |
| Westerham | TN14 | Sevenoaks | 7 h 52 min |
Heat loss surveys questions
Will the survey check noise from the outdoor unit?
Yes. The surveyor identifies possible positions for the outdoor unit and carries out the MCS noise assessment, which estimates the sound level at the nearest neighbouring window from the unit's sound power level, distance and any barriers. In England, meeting the MCS planning standards is one of the conditions for permitted development. Wales, Scotland and Northern Ireland have their own rules, which we check.
How long does a heat loss survey take?
A typical survey takes 1–3 hours on site, depending on the size and complexity of the home. Larger or older houses with mixed construction, extensions or many rooms take longer. The calculations and design are completed afterwards, and the results are included in your quote or stand-alone report.
What is a design flow temperature?
The design flow temperature is the temperature of the water sent to your radiators or underfloor heating on the coldest design day. Heat pumps are more efficient at lower flow temperatures, typically around 35–50°C. Choosing it is a balance: a lower figure improves efficiency but can mean larger radiators in some rooms, so the design shows both.
Is the heat loss survey free?
Yes, for installation enquiries the home survey and heat loss calculation are free, and the results form the basis of your written quote. If you only want the calculation and report, for example for building plans or comparing quotes, a stand-alone heat loss survey has a guide price of £150–£400, including VAT. We confirm which applies when you book.