Do smart thermostats improve your EPC rating?

Smart heating apps like Hive, Nest, tado and Honeywell evohome are now in thousands of Kent homes, and people often ask whether they help their EPC. Some can, a little, but not always in the way people expect, and only if your assessor can see and record them. Here’s what counts, what doesn’t, and what to have ready on the day.

What the EPC actually looks at

An EPC doesn’t measure how clever your heating is. It records how much control the system gives you over where and when the heat goes. For a typical radiator system, the levels run roughly like this:

• No controls at all – the weakest position, and where adding controls makes the biggest difference.
• Programmer and room thermostat – what most homes have.
• Programmer, room thermostat and TRVs – the usual standard, with temperature control room by room.
• A listed smart thermostat – can give a small boost over a standard programmer and room thermostat.
• Time and temperature zone control – the top level for radiator systems, where different parts of the home can be heated at different times and temperatures.

Every step up helps a little, but heating controls are rarely the improvement that changes a band on their own. Exactly what your home would gain is subject to a draft EPC.

Why a smart thermostat only adds a little

A smart thermostat lets you change the heating from your phone, learns your routine and can turn the heating down when you go out. That’s genuinely useful, and it can cut your bills. Under the EPC method (RdSAP 10), a listed smart thermostat can give a small boost over an ordinary programmer and room thermostat. It’s worth having, but don’t expect it to move your home into the next band by itself.

Smart TRVs and zone control

Things improve further when you can heat different parts of the home at different times and different temperatures. The EPC method calls this time and temperature zone control, and it assumes rooms you’re not using sit cooler for more of the day.

There are two main ways a radiator system can qualify. The traditional one is separate plumbing circuits, such as upstairs and downstairs, each with its own timer channel and thermostat. The easier one for most existing homes is smart TRVs: programmable radiator valves that replace the heads on your existing TRVs and give each room its own schedule.

To count, smart TRVs generally need to be on all the radiators outside the room with the main thermostat, not just one or two in the bedrooms. Standard TRVs, however good, only control temperature, not time, so they don’t count as zone control. The gain is real but modest. It’s most useful when a home is close to the next band, and smart TRVs need no building work.

Only listed products count

This is the part most people don’t know. A smart thermostat or smart TRV system only counts on your EPC if its exact make and model is listed on the national product database that EPC software uses. Most well-known brands are on it, including Hive, Nest, tado, Honeywell and Drayton Wiser. If your model isn’t listed, your assessor can’t include it, however good it is.

Tell your assessor: what to have ready

Smart controls are easy to miss. A thermostat on a side table or a small hub by the router doesn’t always look like part of the heating system. We always look, but these things help us record everything correctly:

• Have the app open so we can see your zones and schedules.
• Know the make and model of your thermostat and valves. A photo of the box or the installer’s invoice helps.
• If you have smart TRVs, make sure every radiator outside the thermostat room has one.
• Tell us about any separate upstairs and downstairs heating zones or timer channels.

We can only record what we can see and verify. We’ll never record something that isn’t there, so your EPC holds up if it’s ever checked.

Smart controls, landlords and 2030

Under the government’s stated plans, rented homes will need an EPC of C or above by 1 October 2030. Smart heating controls are rarely enough to get a rental there on their own, but they’re one of the cheapest steps on the way, alongside insulation and solar. See our EPCs for Kent landlords page and our MEES guide for the bigger picture.

Heat pumps, new rules and the bigger picture

Zone control applies to heat pumps as well as boilers. If you’re planning a heat pump, it’s worth talking controls through with your installer at the design stage. Our guide to heat pumps and EPC ratings covers how they score.

Looking further ahead, the EPC method is due to be replaced by the Home Energy Model, now expected from late 2027. The proposals include a measure of how “smart ready” a home is, alongside fabric and heating. The details are still being finalised, so treat any claims about how smart controls will score under the new system with caution.

For most homes, insulation and solar PV still move the rating more than controls do. See our guides to loft insulation and solar panels.

Talk to us first — start with an accurate rating

Every home scores differently, so the honest answer to “how much will smart controls add?” is: it depends on your home and what you have now. A draft EPC gives you an accurate baseline and lets us model the change before you spend anything. Once any work is done, we can lodge your EPC with everything recorded properly.

We assess homes; we don’t sell heating controls or installations, so our only interest is getting your rating right. We cover homes across Kent. Call us on 01304 626457 or get in touch.