- Area
- Gwynedd
- Postcode district
- LL55
- Nation
- Wales
- Guide price
- Priced after survey
- Survey
- Free for installation enquiries
Heat loss survey for Caernarfon homes
Every property in Caernarfon 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.
Design outdoor temperatures for Caernarfon and the wider Gwynedd come from local cold-weather data, not a national average. Homeowners in Caernarfon thinking about insulation work can use the survey to see how it would change their heat pump size.
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.
- Self-builders and architects who need emitter and system sizes early
- Anyone getting a heat pump quote, as the first step
- Homeowners planning insulation or building work who want to know the effect on heat demand
What's included
- 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
- Radiator schedule with any upgrades needed for each room
- Recommended heat pump size and design flow temperature
For Caernarfon homes with extensions or loft conversions, each part of the house is assessed on its own construction.
Grants and rules for heat pumps in Wales
Homes in Caernarfon 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.
Guide prices for heat loss surveys in Caernarfon
The ranges below are typical installed prices for homes in Gwynedd, including VAT. A survey sets the exact figure, because two similar-looking houses in Caernarfon 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–£400 |
Inc VAT. A stand-alone report is for homeowners who want the design without an installation quote.
How long is the heating season in Caernarfon?
On the shortest day Caernarfon gets about 7 hours 32 minutes of daylight, with the noon sun around 13° up. The heating season runs from autumn into spring, so a heat pump that is sized correctly and set up with weather compensation does most of its work in steady, cool conditions.
What happens after you enquire in Caernarfon?
- Tell us about your home: postcode, property type and current heating.
- We book a survey in Caernarfon; the surveyor measures rooms, windows and radiators and looks at cylinder space.
- The design and quote arrive in writing, including radiator changes and the outdoor unit position.
- On installation days the old system is removed and the new one fitted and filled.
- We commission the heat pump, show you the controls and register the installation.
Heat loss surveys in Caernarfon: questions
How soon can you survey a home in Caernarfon?
Survey dates depend on how busy installers are in Gwynedd. We offer the next available dates when you enquire and confirm them in writing.
Where would the outdoor unit go on a Caernarfon house?
Usually at the side or rear, on a level base with space around it for airflow and servicing, away from bedroom windows where possible. The surveyor checks positions at your Caernarfon home.
Can you service a heat pump in Caernarfon that someone else installed?
Yes. We arrange servicing and repairs for most air source heat pumps in Caernarfon, whoever fitted them. Tell us the make and model when you book.
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.