7 Smart Ways to Cut Your Winter Energy Bills in 2025
As we approach winter 2025, homeowners are bracing for another season of high energy costs. This year, however, you don’t have to simply accept rising bills. As an RIBA architect’s practice with Passivhaus expertise, our advice to clients is always rooted in building physics, understanding how heat moves, where losses and gains occur, and how small changes compound over time.
Below are seven smart, technically grounded strategies your home can adopt this winter to reduce your heating and energy bills without compromising comfort.
1. Tune Your Heating System: Lower the Flow Temperature & Use Smart Controls
One of the most underappreciated levers for efficiency lies in your boiler or heating system settings. For condensing (combination) boilers, reducing the flow temperature (i.e. the temperature of water pushed into radiators) to around 60 °C or lower helps the boiler run in condensing mode more often, improving efficiency.
Pair that with a smart or programmable thermostat (or smart radiator valves) so you only heat when and where needed. Many studies show that precise control over timing and zoning can yield savings of 10–15 % on heating bills.
Architect's tip: During design or retrofit projects, integrate heating zones and temperature sensors into every occupied space. Don’t rely on a single “whole-house” thermostat.
2. Seal the Envelope: Attack Draughts & Air Leaks
Even small gaps around windows, doors, service penetrations, skirting boards, or attic hatches can let warm air escape and cold air infiltrate. In a well-insulated home, air leakage may dominate heat loss.
Architect's tip: Use weatherstripping, sealing foam, or acoustic-rated seals. It’s possible to conduct an airtightness test (blower-door test) to find weak spots systematically, something Passivhaus architects do during retrofit and new build projects.
Once sealed, your heating system doesn’t have to “chase leaks,” so less fuel is needed to maintain comfort.
3. Maximise Passive Solar Gain (and Manage Losses at Night)
In winter, daylight is your ally. Open south-facing curtains, blinds, or shutters during sunny hours to let solar gain warm interior surfaces. Then close heavy curtains or insulated blinds after dark to act as a thermal barrier against cold glass.
Also consider secondary glazing or insulated internal panels for older windows, especially in less efficient homes. The goal is to tilt the balance, so solar gain helps you, rather than you simply battling losses.
Architect's tip: Clean your windows. Even a small amount of dirt accumulating on the outside reduces natural daylight within a room resulting in lights being turned on earlier. Dirty windows also reduces solar energy heating the room up in the winter.
4. Bleed & Maintain Radiators; Use Reflection Panels
Radiators that trap air bubbles (i.e. “cold spots”) are less efficient at transferring heat into your rooms. Bleeding your radiators regularly ensures consistent heating performance.
For radiators mounted on external walls, place reflective foil panels behind them (between radiator and wall) to reflect heat back into the room instead of letting it be absorbed by the wall. This is a low-cost, effective trick.
Ensure circulation is not obstructed by furniture or heavy curtains and that radiator valves are functional (thermostatic valves are best).
5. Insulate Strategically: Roof, Floor, Walls & Hot Water
Much of your home’s heat escapes through poorly insulated elements:
Loft/roof insulation
A properly insulated roof is perhaps the single most effective upgrade in many UK homes.
Wall and floor insulation
Especially in uninsulated cavity or solid wall homes, these retrofits pay dividends.
Hot water tank and pipe insulation
A lagging jacket, pipe insulation, and a well-insulated cylinder reduce losses from your water system.
If you’re eligible, look into UK government schemes like the Great British Insulation Scheme or ECO grants to help with the cost.
As an architect’s practice, we always push for an integrated approach: insulation + airtightness + ventilation rather than piecemeal improvements.
6. Use Mechanical Ventilation with Heat Recovery (MVHR)
As airtightness improves, we must still provide fresh air or condensation and mould will result. That’s where MVHR systems come in: they exchange stale indoor air with fresh outdoor air while recovering up to ~80 % of the heat from the outgoing air. In a well-sealed, insulated home this can slash heating demand further.
In a retrofit project, even a simpler heat-recovery ventilation unit (e.g. decentralised HRV in certain zones) can deliver significant gains. Over the year, these systems help maintain indoor air quality without loosing heat unnecessarily.
7. Heat Yourself, Not the Whole House (Smart Habits + Thermal Accessories)
Sometimes the biggest savings come not just from technology, but from clever behaviour. Some approaches worth combining:
Wear insulation: warm clothes, blankets, slippers and reduce the thermostat by 1 °C—you might not even feel the difference.
Use a heated throw, foot warmers, or electric blankets in the evening, heating the person instead of the entire space. Using electric blankets can cost just a few pence per hour compared to heating your entire home.
Close doors to unused rooms; limit heating to zones in active use.
Reduce the flow temperature when running taps or showers (i.e. don’t run hotter than necessary).
Avoid “always-on” devices and vampire loads (appliances in standby) which still draw power. Though not heating, they tax your electricity system overall.
Bringing It Together: A Smart Sequence for Implementation
Baseline audit
Walk through your home (or engage a specialist) and locate insulation gaps, draughts, and inefficient systems. A home energy assessment is a good start.
Essential “quick wins”
Bleed radiators, seal obvious air leaks, reduce thermostat by 1 °C, use reflective panels.
Upgrade central systems
Install smart thermostats, zone control, and adjust boiler flow temperature.
Deep retrofit
Combine insulation and retrofit measures, airtightness, and heat-recovery ventilation.
Behavioural layering
Adopt smart habits and thermal accessories to complement your improved building envelope.
When all seven strategies work in harmony, you could realistically reduce your winter heating demand by 20–30 % (or more, depending on your starting point). That’s not just a financial win, it’s also a meaningful cut in carbon emissions.
If you’re planning to retrofit your home, a large extension or considering a higher-performance new build in the years to come, these strategies are ones we routinely build into client projects. While some require investment, many pay for themselves in a few winters and in an age of volatile energy pricing, lowering demand ultimately supported by renewables is a great investment to make.
If you’d like help evaluating which of these is best for your home and establishing a short- and long-term strategy, we’d be delighted to assist further.