A heat loss survey measures how much heat each room loses at the design outdoor temperature for your area. It takes two to three hours, covers every room, and produces a written report with a room-by-room heat loss calculation, proposed system design, and itemised cost. The survey is no-obligation.
A heat loss survey is the single most important step before installing any heating system, and especially before adding a heat pump. It measures how much heat your home loses at a given outdoor temperature, room by room, and uses that data to size the heat pump, identify radiator upgrades, and estimate running costs. Without a survey, any price or performance claim is a guess. This page explains what the survey covers, how long it takes, and what you receive afterwards.
Last updated: 28 October 2026
Reviewed by the Scottish Energy Efficiency team.
What does a heat loss survey measure?
The survey measures heat loss for every room by calculating the area and insulation value of each external surface — walls, windows, doors, floor, and roof — against the design outdoor temperature for your area of Scotland.
The surveyor visits your home and measures each room, noting external wall area, window sizes and glazing type, door types, floor construction, and ceiling or loft insulation depth. These measurements are used to calculate the heat loss in watts for each room at the design outdoor temperature — the temperature your area is expected to drop to during a cold spell. In most of Scotland this is around -3 to -5 degrees. The total heat loss across all rooms determines the heat pump capacity needed. The surveyor also measures each radiator to check whether it can deliver enough heat at the lower flow temperatures a heat pump uses, or whether it needs upgrading.
How long does the survey take?
The survey takes two to three hours for a typical three or four bedroom home. It covers every room, the loft, the hot water system, the outdoor location, and the electrical supply.
The surveyor needs access to all rooms, the loft if you have one, the boiler and cylinder, and the outside of the property. They measure, photograph, and note construction details for each space. They inspect the loft to check insulation depth and ceiling condition. They assess the hot water cylinder size and condition. They look at potential locations for the outdoor unit — a side or rear wall, or a ground-mounted pad — checking airflow and proximity to the indoor module. They check your electrical consumer unit and supply capacity to confirm it can support the heat pump. After the visit, the calculations and system design are completed off-site, and the written report is prepared.
What do I receive after the survey?
You receive a written report with a room-by-room heat loss calculation, a proposed system design, a list of any radiator changes, an estimate of running costs, and an itemised installation cost. No installation is booked until you review and approve it.
The report is the basis for everything that follows. It sets out the heat loss for each room in watts, the required heat pump capacity, the proposed flow temperature, and the bivalent point — the outdoor temperature at which the boiler takes over. It lists any radiators that need upgrading, with the recommended size for each. It includes a system diagram showing the heat pump, boiler, cylinder, and controller connections. It provides an estimate of annual running costs based on your current fuel type and typical usage. And it includes an itemised installation cost, with each component priced separately so you can see exactly what you are paying for. You are under no obligation to proceed.
Why can you quote without a survey?
We cannot. Any price given before a survey is a rough range, not a quote. The survey is the only way to produce an accurate, itemised proposal that accounts for your specific property.
We can give you a typical cost range over the phone or on the website to help you understand the scale of investment, but that range can vary by thousands of pounds depending on what the survey finds. A home with good insulation and correctly sized radiators may need minimal ancillary work. A home with solid walls, single glazing, and an ageing boiler may need significant upgrades. Without measuring the actual heat loss, we cannot size the heat pump, cannot confirm radiator compatibility, and cannot price the work accurately. This is why the survey comes first, always, and why the written proposal is produced after the survey, not before.
What happens if the survey shows my home is not suitable?
We tell you. If the survey shows that a hybrid system will not perform well in your home — due to poor insulation, no space for the outdoor unit, or an inadequate electrical supply — we will say so and explain what would need to change.
Not every property is suitable for a hybrid system, and installing one that will not perform wastes your money and our reputation. If the survey identifies a dealbreaker — such as no location for the outdoor unit, an electrical supply that cannot be upgraded, or insulation levels too poor for the heat pump to work efficiently — we will tell you directly. In some cases the solution is to address the underlying issue first: insulate the loft, upgrade the consumer unit, or create space for the outdoor unit. In other cases a hybrid system simply is not the right approach, and we will explain why. We do not install systems that will not perform. We install through MCS-certified partners.
Frequently asked questions
Is the heat loss survey no-obligation?
Yes. The survey is no-obligation, takes two to three hours, and you are under no obligation to proceed after receiving the report.
Do I need to prepare anything before the survey?
Just ensure the surveyor can access all rooms, the loft, and the outside of the property. No special preparation is needed.
How soon after the survey do I get the report?
The written report is typically ready within three to five working days. The surveyor confirms the timeline at the visit.
What if I disagree with the survey findings?
The report is transparent — you can see every measurement and calculation. If you have questions, we explain them. You are under no obligation to proceed.
Can I use the survey report to get quotes from other installers?
Yes. The report is yours. It contains the heat loss data any installer would need to price a system for your home.
Fill in the form and we will call you within one working day to arrange a survey. No obligation · We install through MCS-certified partners · Scottish homes and businesses
