Energy bills in the UK are still running significantly higher than most households were used to before 2021, and for anyone living in an apartment, the options for cutting costs can feel limited. You can’t just add loft insulation or install solar panels if you’re on the third floor. That leaves many renters and flat owners wondering what they can actually do. Here’s what you actually need to know.
I’ve been writing about UK household costs long enough to notice a pattern. People in apartments tend to assume they’re stuck with whatever the landlord provides and whatever the energy company charges. That’s not entirely true. There are practical, low-cost changes that genuinely move the needle on your monthly bill, and they don’t require structural changes to the building. Before you resign yourself to another winter of expensive heating, it’s worth understanding what your lease says about utilities — because some of the best savings start with knowing what you’re actually paying for.
What energy efficiency actually means in a flat
The biggest difference between a house and an apartment is that you share boundaries. Heat from your flat escapes into the hallway, through the walls, and out of single-glazed windows — and you’re paying for all of it. The core idea behind energy efficiency in a flat is simple: stop paying to heat the outside. Every change you make should aim to keep the warmth you generate inside your four walls for longer.
What I’d do first is look at the things that cost almost nothing to change. Lowering your boiler flow temperature takes about ten seconds on the control panel. Swapping a few bulbs takes an afternoon. Those two actions alone can cut your energy use noticeably, and they don’t require permission from anyone.
Why this matters more than you think
The UK is pressing ahead towards its net zero 2050 target, and energy prices in 2026 are still significantly higher than many households were used to before 2021. That means the cost of doing nothing is real. A gas or oil boiler more than 10–12 years old is likely to be less efficient than modern models, so if you’re in a flat with an older system, you’re burning more fuel than necessary for the same amount of heat.
Consider this scenario: you live in a top-floor flat with single-glazed windows and an old combi boiler. Your heating comes on twice a day, but the rooms never feel properly warm. You turn the thermostat up, which costs more, and the heat still escapes. The fix isn’t a new boiler — that’s the landlord’s job. The fix is draught-proofing, radiator reflector panels behind radiators on external walls, and well-fitted, lined curtains closed at dusk to reduce heat loss through glass. Those changes cost a fraction of a heating bill and work immediately.
I’ve seen this pattern repeatedly: people in flats assume they have no control, so they don’t try anything. That assumption is costing them. First-time renters especially often don’t realise how much small changes add up over a year.
Where people go wrong
Most mistakes come from assuming that energy efficiency requires major work or spending. It doesn’t. Here are the three most common errors I see.
Ignoring the boiler settings
A combi boiler flow temperature should be lowered to around 55–60°C for better efficiency. Most installers leave it set at 70°C or higher, which wastes gas. If you have a hot water cylinder, it must be kept at least 60°C to prevent legionella — but that’s a different setting. People often confuse the two and leave both too high. The fix: find your boiler’s manual or look up the model online, then adjust the flow temperature yourself. It takes seconds.
Heating empty rooms
Smart TRVs control individual rooms so you only heat the spaces you use. Without them, you’re heating the entire flat to the same temperature even when you’re only in the living room. Smart heating controls can cut gas use in many UK homes by avoiding unnecessary heating. If you can’t install smart TRVs because you rent, at least turn the radiator valves down manually in rooms you don’t use. It’s not as precise, but it still saves money.
Overlooking draughts and heat loss
Draught-proofing doors, windows and floors can make rooms feel warmer at a lower thermostat setting. Open chimneys can be a major source of heat loss — if you have one, get a chimney balloon. Radiator reflector panels behind radiators on external walls reduce heat loss through solid walls. These are all cheap fixes that people skip because they don’t look dramatic. But a room that holds heat better needs less energy to stay warm.
→ Scroll right to see all columns
| Change | Typical saving | Upfront cost |
|---|---|---|
| LED bulbs | Up to 80% less electricity per bulb | Low (few pounds per bulb) |
| Lower boiler flow temp to 55–60°C | Moderate gas saving | Free |
| Draught-proofing | Noticeable warmth improvement | Low (strips, sealant) |
| Smart TRVs | Reduced gas use in unused rooms | Moderate (£20–40 per valve) |
What I’d do if I were in a flat right now: buy a pack of LED bulbs, a draught excluder for the front door, and a roll of self-adhesive foam strip for the windows. That’s about £20 total and will make a difference before the end of the week.
Writing about topics like this takes real time and research. If you buy something through an Amazon link on this page, I may earn a small commission — at no extra cost to you. It’s one of the things that makes it possible to keep BritWealth free to read. I only link to products that are genuinely relevant to the article.
Practical steps to cut your energy use starting today
These are the actions that actually work in a UK apartment. They’re ordered from quickest to most involved, so you can start with what’s easiest.
Swap your lighting to LEDs
LED lighting uses up to 80% less electricity than old halogen or incandescent bulbs. If your flat still has halogens in the ceiling spots or table lamps, replace them. A pack of LED light bulbs costs very little and will pay for itself within months. Check the fitting type before you buy — most UK flats use bayonet (B22) or screw (E27) bases.
Adjust your heating controls
If you have a combi boiler, lower the flow temperature to around 55–60°C. If you have a hot water cylinder, keep it at 60°C minimum for safety. Smart heating controls can cut gas use by avoiding unnecessary heating — a smart thermostat or smart TRVs let you schedule heat only when and where you need it. If you rent, ask your landlord before changing any fixed heating equipment, but adjusting the boiler flow temperature is usually fine.
Draught-proof and insulate what you can
Draught-proofing doors, windows and floors can make rooms feel warmer at a lower thermostat setting. Use self-adhesive foam strips for windows, a brush strip for the bottom of the door, and sealant for gaps in floorboards. Well-fitted, lined curtains closed at dusk help reduce heat loss through glass. Radiator reflector panels behind radiators on external walls reduce heat loss through solid walls — these are cheap and easy to install.
Use smart plugs and energy monitors
Smart plugs with energy monitoring can show real usage from devices. You’ll quickly see which appliances are drawing power when they shouldn’t be. Turn off standby devices at the plug. Wash clothes at 30°C where possible. These are small habits, but they add up over a year. Your apartment leasing checklist probably didn’t cover energy habits, but they matter just as much as the terms of your tenancy.
Frequently asked questions
Can I install smart heating controls if I rent? ▾
Will lowering my boiler flow temperature make my flat colder? ▾
What’s the cheapest way to reduce heat loss from windows? ▾
Do radiator reflector panels actually work? ▾
Should I turn my heating off when I’m out all day? ▾
Can I get paid for generating solar energy in a flat? ▾
Energy efficiency in a flat isn’t about big renovations. It’s about the small, cheap changes that stop heat escaping and stop you paying for energy you don’t use. Start with the bulbs and the boiler setting. That alone will save you money this month. If this was useful, you might also want to read apartment hunting in the UK — avoid these common tenant traps.
Sources and Further Reading
Guarantor-free renting in the UK — A practical guide for tenants who want to lease without a guarantor, covering the options available and what to watch out for.
Warm Homes Plan. Department for Energy Security and Net Zero, 2026.
UK home energy cost saving tips for 2026. Energy Plus, 2026.
