Cheapest Ways to Improve Your EPC Rating: Top 5 Under £500

The five cheapest improvements — LED lighting, draught-proofing, a hot water cylinder jacket, heating controls and loft insulation — are inexpensive relative to fabric or heating work, permanent, and credited in every future assessment. For a property near the top of its band, they are often the whole job.

Why cheap improvements matter

Most of the marketing attention around EPC improvements focuses on heat pumps, external wall insulation, and solar panels, measures that cost £5,000–£20,000. These are important for reaching band B or A, but for the majority of London landlords and homeowners who need to move from E to D, or D to C, the cheap measures are where to start.

The logic is simple: do the cheap things first. They often deliver enough points. If they don't, you've made the building more efficient before the expensive measures, which maximises their effectiveness.

The five best improvements under £500

1. LED lighting throughout

RdSAP 10 credits the proportion of light fittings that are low-energy. If all your fixed fittings are LED, you get maximum lighting credit. If none are, you get minimum credit.

The more of your fixed fittings are already low-energy, the less there is to gain — which is why this measure matters most in a house still running halogens.

Tip: The assessor counts fixed light fittings (ceiling roses, wall lights, downlights). Plug-in lamps on tables don't count. Ensure all fixed fittings have low-energy bulbs in place at the time of the assessment.

The effect is largest where you are replacing halogens (GU10 spotlights), which are treated as high-energy fittings.

2. Loft insulation to 270mm

If you have an accessible pitched loft with less than 270mm of insulation, topping it up is the highest-impact of the cheap measures — and may be funded under ECO4 or GBIS, see below.

The assessment credits insulation depth, measured at the time of the visit. Ensure the loft is accessible for the assessor and the insulation is freshly laid and at depth.

Free routes:

• ECO4: Fully funded for benefit-receiving households in D–G properties
• GBIS: Funded for properties in council tax bands A–D without benefit requirement

If you qualify for either scheme, this is effectively free and should be your first action. Apply through your energy supplier.

3. Draught-proofing

Draught-proofing reduces the measured air leakage rate used in the SAP calculation. Gaps around windows, doors, skirting boards, loft hatches, and pipework all allow cold air in and warm air out.

RdSAP 10 doesn't separately survey draught-proofing as an installation item, it's captured as part of the overall air permeability assessment. However, draught-proofing is listed as a recommended improvement on most EPCs for pre-1980 properties, and its presence is noted by an assessor.

What to tackle:

• Loft hatch: fit a 25mm insulated board cover (£15–£30 DIY)
• External doors: fit brush or rubber seal strips (£5–£10 per door)
• Sash windows: fit brush strip around the frame (£15–£25 per window)
• Chimney (if unused): fit a chimney balloon or draught excluder (£20–£30)
• Letterbox: fit an insulating cover (£5–£10)

Draught-proofing is largely DIY-able, which is what keeps it cheap; an installer costs more but covers the whole property properly.

4. Hot water cylinder jacket

If your property has a separate hot water storage cylinder (rather than a combi boiler which heats water on demand), a well-insulated jacket dramatically reduces standing heat loss.

An uninsulated cylinder loses useful heat continuously to the surrounding air. RdSAP records cylinder insulation type and thickness separately, so an adequately insulated cylinder is credited where a bare one is not.

Check:

• Does your cylinder have a jacket? (A white or silver foil-wrapped jacket around the outside)
• Is it 80mm thick? (Check by feel, a thin jacket is 25mm, a proper one is 80mm+)

If it is uninsulated or thinly insulated, a jacket is inexpensive, widely available and takes about half an hour to fit. Pound for pound it is the best-value item on this list.

5. Heating controls

RdSAP 10 separately credits three control types:

• Room thermostat: the main heating is controlled by a thermostat in the living area, not just a timer.
• Programmer (timer): heating runs on a timed programme rather than manual-on-permanent.
• Thermostatic radiator valves (TRVs): each radiator can be controlled individually.

Each is recorded separately, so a property missing all three has more to gain than one that already has a thermostat.

If all three are already present, there's nothing to add. If any are missing, adding them contributes points.

Smart thermostats (Nest, Hive, tado) qualify as room thermostats in RdSAP 10, they don't receive additional credit beyond standard room thermostat credit, but they do qualify.

Installation:

• Smart thermostat + programmer: DIY, or fitted by a heating engineer
• TRVs (replacing manual valves): inexpensive per radiator as a DIY job, or a modest plumber cost for the whole house

Combining the five measures

Working through the list in order — lighting, then loft, then controls, then draught-proofing and the cylinder — is the cheapest sequence, because it puts the least expensive measures first and leaves the fabric and heating work until it is genuinely needed.

What that sequence is actually worth on your property is calculated from the whole dwelling, and your EPC recommendation report shows an indicative rating after the recommended measures for that specific home.

This example crosses into C with just loft insulation and LEDs, the additional measures provide margin and comfort benefits. For a property already at D65 or above, LEDs and loft insulation alone are likely enough.

If loft insulation is funded through ECO4 or GBIS, the remaining measures comfortably fit a small budget.

What won't make the list cheap enough

These are commonly suggested but won't fit under £500 in most cases:

• New boiler: one of the biggest levers where the existing unit is an older non-condensing type, but well above a £500 budget.
• Cavity wall insulation: usually just over a £500 budget, but close — and potentially free under ECO4 or GBIS.
• Solar PV: £5,000–£9,000. Transformational for band B, not cheap.
• Double glazing: expensive, and changes little where the property already has double glazing — which most London stock does.

For a full ranked list of all improvements with costs and point gains, see our complete EPC improvement guide. For landlord-specific compliance planning, see our EPC for landlords 2026 guide.

Book an EPC assessment to get your exact SAP score and a personalised improvement plan. We cover all London boroughs, including Hackney, Islington, Ealing, Bromley, Enfield, Croydon, and 28 others, with guide prices from £65 and your exact quote confirmed before booking.