EPC Rating C by 2028: What UK Landlords Need to Do Now

2026-09-29

The Regulation That's Coming — and Why Most Landlords Aren't Ready

Under proposed legislation, all new tenancies will need an EPC rating of C or above from 2025, with existing tenancies required to meet the standard by 2028. While the exact timeline has shifted with political cycles, the direction of travel is clear: energy-inefficient rental properties will become unlettable.

Currently, the minimum standard is EPC E. Properties rated F or G can't legally be let unless they have a valid exemption. Raising the bar to C affects a massive portion of the rental stock — an estimated 55% of privately rented homes in England currently fall below EPC C.

If your property is rated D or E, the question isn't whether you'll need to upgrade. It's whether you do it now, when you can plan and budget, or later, when every contractor in the country is booked and prices have doubled.

What Is an EPC Rating, Really?

An Energy Performance Certificate rates a property from A (most efficient) to G (least efficient) based on its energy use per square metre. The assessment covers the building fabric (walls, roof, floor, windows), the heating system, hot water, lighting, and ventilation.

The rating is calculated using a standardised methodology called SAP (Standard Assessment Procedure). Crucially, it measures the building, not the occupant. It doesn't matter how carefully your tenant uses energy — if the walls leak heat, the rating is low.

Each EPC comes with a list of recommended improvements, each showing the estimated impact on the rating and the cost range. Not all recommendations are equal, and not all are worth doing. Understanding which improvements give you the most rating uplift per pound spent is the key to making this affordable.

Which Improvements Actually Move the Needle

Based on SAP methodology and real-world EPC assessments, here are the improvements ranked by typical cost-effectiveness:

High Impact, Lower Cost

• Loft insulation (270mm mineral wool): £300 to £600. Can add 5 to 15 rating points if the loft is currently uninsulated or has old, thin insulation. This is almost always the first thing to do.
• Cavity wall insulation: £500 to £1,500. Adds 5 to 12 points on properties with unfilled cavities. Not applicable to solid-wall properties.
• Smart heating controls and a programmable thermostat: £150 to £400. Adds 2 to 5 points. Cheap and easy.
• LED lighting throughout: £50 to £200. Adds 1 to 3 points. Minimal cost for a free improvement.
• Hot water cylinder insulation (80mm jacket): £20 to £50. Adds 1 to 2 points if the existing jacket is thin or missing.

Medium Impact, Medium Cost

• Condensing boiler replacement: £2,500 to £4,500. Adds 5 to 15 points if replacing an old non-condensing boiler. The single biggest improvement for gas-heated homes with ageing boilers.
• Double glazing (replacing single glazed): £3,000 to £8,000. Adds 3 to 8 points. Expensive per point gained, but often necessary.
• Floor insulation: £800 to £2,000. Adds 2 to 5 points. Practical on suspended timber floors, less so on solid concrete.

High Impact, High Cost

• External wall insulation (solid walls): £8,000 to £15,000. Adds 10 to 20 points. The nuclear option for solid-wall Victorian terraces. Expensive but often the only way to reach C on older properties.
• Internal wall insulation: £4,000 to £8,000. Adds 8 to 15 points. Cheaper than external but reduces room sizes and requires refitting skirting boards, sockets, and radiators.
• Air source heat pump: £8,000 to £14,000. Adds 10 to 25 points. Transformative for the EPC rating but requires suitable property, potentially new radiators, and a well-insulated building to work efficiently.

The Cost-Effective Path from D to C

Most D-rated properties need 10 to 20 additional SAP points to reach C. A typical upgrade path:

• Top up loft insulation to 270mm: £400 (+8 points)
• Install smart thermostat: £250 (+3 points)
• LED lighting throughout: £100 (+2 points)
• Upgrade boiler to condensing combi: £3,200 (+10 points)

Total: approximately £3,950 for roughly 23 SAP points. That's enough to take most D-rated properties into C territory.

For E-rated properties, the path is harder and more expensive. You're typically looking at £5,000 to £12,000 depending on the building type and which improvements are applicable.

The Cost Cap and Exemptions

The current minimum energy efficiency regulations include a cost cap: landlords don't have to spend more than £3,500 (including VAT) to reach the required standard. If you can demonstrate that you've spent up to the cap and still can't reach the target rating, you can register an exemption.

Under the proposed EPC C regulations, the cost cap is expected to increase — potentially to £10,000. The exact figure will depend on the final legislation. Budget for the higher number.

Even with a cost cap, exemptions aren't a get-out-of-jail-free card. They expire after five years, they require documentary evidence, and they may not protect you from tenants who prefer to rent energy-efficient homes. An exempt D-rated property competes poorly against a C-rated property next door.

Does the Investment Pay for Itself?

This is the question that matters. If you spend £4,000 to move from D to C, do you get that back?

Three ways it pays:

• Rental premium: Energy-efficient properties command 3-5% higher rents in many markets. On £800/month, that's £288 to £480 per year. Payback in 8 to 14 years on a £4,000 investment.
• Reduced voids: Tenants increasingly filter by EPC rating. A C-rated property lets faster than a D, especially in competitive markets.
• Property value: Studies consistently show a 5-8% value premium for properties at EPC C compared to EPC D. On a £200,000 property, that's £10,000 to £16,000 — far more than the improvement cost.

The maths almost always works, especially when you factor in the certainty that the regulation is coming. The question is whether you invest now at a reasonable cost or wait until demand for contractors and materials spikes.

What to Do This Month

Check your current EPC rating. If it's D or below, get a fresh EPC assessment done — the recommendations tell you exactly what to prioritise. Then cost each improvement against the SAP points it delivers and start with the highest-return items first.

Don't wait for the legislation to be finalised. The work needs doing regardless. The landlords who act early will get better prices, better contractors, and better tenants.