Scotland Regional Winner, Heating Installer Awards 2026Highly Commended, Scottish Energy Efficiency Awards 2025
🎉 Scotland Regional Winner at the Heating Installer Awards 2026
Scotland Regional Winner, Heating Installer Awards 2026Highly Commended, Scottish Energy Efficiency Awards 2025
🎉 Scotland Regional Winner at the Heating Installer Awards 2026
Home / Blog / Heat pump survey in Scotland
A heat pump survey is the visit where an engineer measures your house room by room, works out how much heat each room loses on a cold Scottish winter day, and designs the system around those figures. The size of the outdoor unit, the radiators that stay on the wall, the cylinder and where it goes all come out of that one visit.
Sean Hogan · Heat Geek engineer · Updated October 2026 · 12 min read
If you know what a thorough survey covers, you can judge an installer while their engineer is still standing in your hall. A tape measure, a notepad of wall types and questions about the rooms you use are good signs. A glance at the boiler and a price by the end of the visit is a bad one.
A gas or oil boiler forgives a bad guess. It sends water round the radiators at 70°C or more, so a boiler sized by habit still warms the house and burns extra fuel doing it.
A heat pump runs at far lower flow temperatures, and it stays efficient when its output matches the heat your house loses on a cold day.
Our own designs show the range: 35°C through underfloor heating in a Bathgate new build, 45°C through radiators in a 1920s sandstone end-terrace in Mount Florida. An undersized unit leaves the back bedroom cold in January, and an oversized one cycles on and off, which costs you efficiency and wears the compressor.
The survey finds the number the whole design hangs on. MCS calls it the design heat load: the heat your house loses, room by room, at the coldest conditions your area is designed for.
In Scotland that number varies a great deal between houses that look alike from the street. A sandstone tenement flat with neighbours above and below loses heat through one or two outside walls.
A detached stone cottage with the same floor area loses it through four walls, a roof and a solid floor, and often through an open fireplace too. At Aventus Eco a heat pump engineer carries out the survey, and the quote you receive comes from what they measure.
The calculation follows a British and European standard, BS EN 12831-1:2017. MCS requires a room-by-room calculation to that standard for every certified heat pump installation, under its heat pump design standard, MIS 3005-D.
For each room, your engineer records:
length, width and ceiling height
each outside wall, window, door, floor and ceiling, and what it is built from (solid sandstone, cavity brick, timber frame, harled block) with any insulation added since
glazing type, from original single-glazed sashes to modern double or triple glazing
ventilation, including open chimneys, air bricks and extractor fans
the temperature you want in that room, since the standard lets a bathroom sit warmer than a spare bedroom
Each element of the building gets a U-value, the rate at which it lets heat through. The calculation multiplies each U-value by the element’s area and by the gap between the room temperature and the design outdoor temperature for your location, then adds the heat lost through ventilation.
Scottish design temperatures sit colder than most of England’s, which is one reason a heat pump sized on a template from a national sales script can come up short in Stirling or Livingston.
Add the rooms together and you have the design heat load of the house in kilowatts, which sets the size of the heat pump. The room figures matter as much as the total, because they tell the engineer what output each radiator needs at the chosen flow temperature.
The kilowatt figures for typical house types, and what happens when a unit is oversized, are set out in our air source heat pump sizing guide for Scotland.
Sean is Heat Geek Mastery trained, and that training puts this calculation first: the radiator choices, the flow temperature and the weather compensation curve set at commissioning all follow from it.
“We initially had Sean over to provide a quote, and as we didn’t know much about heat pumps, he explained everything clearly and in a way we could easily understand. He emphasized the importance of proper heat loss calculations for our property, which helped us determine which existing radiators we could keep.”
Marie Penrice, ★★★★★ Google Review
With the building measured, the rest of the visit turns to the heating kit, and each check can change the design or the price.
Your engineer notes the type and size of every radiator and compares its output at the design flow temperature with the heat loss of its room.
A radiator sized for 70°C water gives out much less at 45°C, so some stay, some get swapped for a larger or double-panel model, and a cold room may gain a second one. The method behind those decisions is covered in our guide to heat pump radiator sizing.
Heat pumps move more water than boilers, at a lower temperature. The engineer checks pipe sizes and traces the main runs, because narrow microbore pipe feeding several radiators can restrict flow and may need part of the circuit upgraded.
A heat pump heats your hot water through a cylinder. Combi households need a spot for one, and the survey finds it: an old airing cupboard, a utility room, a basement or a cupboard under the stairs. The engineer also checks the route for pipes between the cylinder and the outdoor unit.
The unit needs clear airflow, a solid base, somewhere for condensate to drain and a sensible pipe run to the house. Your engineer also checks the position against the MCS 020 noise assessment for the nearest neighbour and the permitted development conditions, which our heat pump planning permission guide explains in full.
The engineer looks at your consumer unit and incoming supply, since every heat pump connection has to be notified to the local network operator. They also note the system you have now, gas, oil, LPG or electric storage heaters, and ask for your recent energy use.
A heat loss calculation works from standard U-values for each type of wall, window and roof.
A thermal camera shows where your house departs from the standard.
Our engineers use a thermal camera on surveys when conditions allow, and it picks up things a tape measure never will: a patch of ceiling where the loft insulation stops short, cold air round a sash window, a cold corner where a wall meets the floor, or a radiator that is cold across the bottom because of sludge.
Some of those findings change the figures. Others point to cheap fixes worth doing before the heat pump goes in, such as topping up loft insulation or draught-proofing a front door, because each one lowers the heat loss and can bring the heat pump size down.
The camera needs a temperature difference to show anything, so it tells you most when the heating is on and it is cold outside. A survey in January reveals more than one in July, though the calculation works in any season.
“What really stood out was the additional guidance Sean provided about how we could improve our home’s insulation and reduce drafts. He explained how making these simple DIY improvements would help lower the heat loss in our home, ultimately reducing our energy bills in the long run.”
Tony McCole, ★★★★★ Google Review
Penny and Monique’s sandstone end-terrace sits a short walk from Hampden Stadium. The house was old, draughty and short on insulation, and they had been told a home like theirs could not run on a heat pump. We started with a detailed heat loss survey, and the design came out of it:
a 7kW Vaillant aroTHERM plus running at a 45°C flow temperature
four radiators replaced with modern high-output models, one added upstairs and two new ones for the rear extension
a 250 litre Vaillant cylinder and the main system components housed in a 1.2 metre high basement, keeping the living space upstairs clear
poor plumbing from an earlier job found and put right along the way
The house now holds a steady 21°C throughout, all year round. Our heat pump installations in Glasgow start with the same survey, whatever the age of the building.
“The house is warm all the time, the new radiators look great, and we love that the whole system is neatly hidden away in the basement.” Penny & Monique, Mount Florida, Aventus Eco case study
After the survey Aventus Eco sends a written proposal with the system design and the costs, and helps you with the Home Energy Scotland grant paperwork. From a survey done to MCS standards, expect to see:
the heat loss of each room and the design heat load of the whole house
the heat pump model and size, with the design flow temperature
a radiator schedule showing which radiators stay, which change and any being added
the cylinder size and where it goes
the outdoor unit position
an MCS performance estimate for the system
A price given over the phone, or worked out from floor area and the size of your old boiler, has none of that behind it. Home Energy Scotland’s own checklist for heat pump quotes tells homeowners to expect an explanation of how the installer calculated the property’s heat demand.
If you collect two or three quotes and the heat pump sizes differ by several kilowatts, ask each installer for their heat loss figure and design flow temperature. The installer who can show you the room-by-room calculation has done the survey.
“They took the time to get the design right for my home, including properly working out our power use and heat loss and sizing everything accordingly.”
Duncan Livingstone, ★★★★★ Google Review
In Scotland, heat pump funding comes through Home Energy Scotland: a grant of up to £7,500, or £9,000 in remote rural, island and off-gas accessible rural areas, plus an optional interest-free loan of up to £7,500. The heat pump has to supply all of your heating and hot water, so hybrid systems are not eligible, and a heat pump that replaces an existing heat pump qualifies for loan funding only.
The survey sits early in the process. Home Energy Scotland’s published steps run in this order:
Contact Home Energy Scotland on 0808 808 2282 for advice. An adviser checks your eligibility and refers you on to the online application.
Get itemised quotes from MCS-certified installers. Home Energy Scotland suggests three, and each quote has to be dated, on headed paper, addressed to you, show the installation address and break down the work and costs.
Submit the application with your chosen quote. Home Energy Scotland aims to process complete applications within 10 working days.
Wait for the funding offer in writing. No installation work can start before it arrives, and Home Energy Scotland does not fund work that has already started.
Complete the installation and submit the final claim within nine months of signing the funding agreement.
An MCS installer cannot produce a compliant design, or an honest itemised quote, without the heat loss calculation, so the survey comes before step 2. We help customers with the grant paperwork and write the quote in the format Home Energy Scotland asks for. The eligibility rules and loan terms are covered in more depth in our heat pump grants in Scotland guide.
The visit runs as long as the house needs. A two-bedroom tenement flat has fewer rooms, walls and radiators to measure than a four-bedroom villa with a rear extension and a converted loft, and the time slot is confirmed when you book.
You will get more from the visit if you have these ready:
your energy bills or usage for the last 12 months (kWh of gas or electricity, or litres of oil)
your EPC, if you have one
clear access to the loft hatch, the consumer unit, the utility room and any airing cupboard
a note of rooms you keep warmer or cooler than the rest, and any room that never heats properly
plans for the next few years, such as new windows, an extension or a loft conversion
Your plans for the house count too. A kitchen extension adds heat loss, and new double glazing takes some away, so telling the engineer lets them design for the house you will be living in.
A survey gives you the heat loss of your house, room by room, and a design you can check line by line against any other quote. Book one and you will know what your house needs and what it will cost after any grant funding.
Aventus Eco’s heat pump survey costs £0, and the heat loss calculation is part of it. Independent energy assessors charge for a standalone heat loss report, but an MCS installer needs the calculation to design the system, so it comes with the survey and quote.
In practice, yes. Home Energy Scotland asks for an itemised quote from an MCS-certified installer with your application, and an installer cannot price a compliant design without a heat loss calculation. Contact Home Energy Scotland first for advice, then have the survey, then apply with the quote.
It depends on the size and layout of the property, since the engineer measures every heated room, checks each radiator and looks at the pipework, cylinder space and outdoor unit position. A small flat takes less time than a large detached house, and the time slot is confirmed when you book.
No. An EPC rates the whole property on a standard scale using broad assumptions. A heat loss survey measures each room and calculates its heat loss at your area’s design temperature, which is the detail a heat pump design needs. An EPC is still useful to have ready for the survey.
Yes. The engineer compares each radiator’s output at the design flow temperature with the heat loss of its room. The proposal lists which radiators stay, which get replaced with larger models and whether any room needs an extra one.
An installer can put a number on it, but without a room-by-room calculation the number is a guess. MCS requires a room-by-room heat loss calculation to BS EN 12831-1:2017 for certified installations, and a Home Energy Scotland grant needs an MCS-certified installer. A size worked out from floor area or the old boiler risks a unit that runs cold in winter or cycles on and off.
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