Domestic EPC Changes: What Tradespeople Need to Know

Quick Answer: The current minimum EPC rating for privately rented properties in England and Wales is band E under the Minimum Energy Efficiency Standards (MEES). The Labour government has proposed raising this to band C — required for new tenancies from 2028 and all tenancies by 2030 — with a landlord spending cap of £15,000. Final regulations are expected but not yet enacted as of April 2026. Approximately 3.5 million rented homes currently sit below band C.

Summary

Energy Performance Certificates have been a legal requirement for properties being sold or let since 2008, and the EPC rating has become central to both regulatory compliance and retrofit funding decisions. The trajectory since 2020 has been clear: the minimum rating floor is rising. In September 2023 the Conservative government abandoned its proposed EPC C requirement for rented properties, citing cost pressures on landlords. The incoming Labour government reversed course, reinstating a similar target — EPC C for all rented properties by 2030, with new lettings required to comply from 2028.

As of early 2026, those targets represent firm policy but are not yet enacted in secondary legislation. The current legal floor remains EPC E. However, the direction of travel is firmly established, and many landlords are already commissioning retrofit work in advance of the deadline. For tradespeople working in insulation, heating, glazing, and renewables, this policy represents the largest sustained demand driver in residential retrofit for a generation.

The scale of the problem is substantial. Approximately 3.5 million privately rented homes sit below EPC C in England alone. Government funding schemes — ECO4, the Great British Insulation Scheme, and the Boiler Upgrade Scheme — are already directing money into this work for eligible households. Understanding how EPCs are assessed, which measures move the needle most, and how the funding frameworks operate is now core commercial knowledge for any tradesperson working in the retrofit space.

Key Facts

Quick Reference Table

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Measure Typical SAP Improvement Cost Range Funding Route
Loft insulation (top-up to 270mm) 2–8 points £300–£800 ECO4, GBIS
Cavity wall insulation 3–10 points £500–£1,500 ECO4, GBIS
External wall insulation (EWI) 5–15 points £8,000–£20,000 ECO4
Internal wall insulation (IWI) 4–12 points £4,000–£12,000 ECO4 (limited)
Air source heat pump 10–20+ points £10,000–£18,000 BUS (£7,500 grant)
Replacement double to triple glazing 1–4 points £4,000–£12,000 Rarely funded
Solar PV (3–4kW) 5–15 points £5,000–£8,000 None currently
Smart heating controls 1–3 points £200–£600 ECO4 (with other measures)
Underfloor insulation (suspended floor) 1–4 points £1,000–£3,000 ECO4
Draught proofing 1–2 points £100–£400 ECO4 (combined with other measures)

Detailed Guidance

How the SAP Scoring System Works

SAP (Standard Assessment Procedure) is the government's methodology for modelling a dwelling's energy performance. The DEA visits the property, records the construction type, approximate dimensions, glazing type and area, heating system, hot water provision, ventilation, and any existing insulation or renewables. This data is entered into accredited SAP software, which models the estimated annual energy costs and outputs a score from 1 to 100.

Each improvement adds SAP points depending on the property's baseline. The same loft insulation upgrade adds more SAP points in a property with no existing insulation than in one already reasonably efficient. This non-linearity is why tradespeople should never guarantee a specific EPC rating improvement: the assessor calculates the final figure from a whole-property model, not from individual measures in isolation.

For a property hovering at the D/C boundary (SAP 62–68), relatively modest improvements — loft insulation plus cavity wall insulation — can be enough to cross the line at SAP 69. For properties at E or F, significantly greater investment is typically required, often including wall insulation and sometimes heating system replacement.

DEAs assess what they can observe and measure. If cavity wall insulation has been installed but is not registered with CIGA (the Cavity Insulation Guarantee Agency) or otherwise documented, the assessor may not credit it. Encouraging customers to commission a new EPC after any improvement works — and to provide documentation — is good practice and protects the value of the work.

What Moves the EPC Rating Most

Space heating typically accounts for 60–70% of a residential property's energy consumption, so measures that reduce heat demand or improve heating system efficiency produce the greatest SAP gains.

Loft insulation is consistently the most cost-effective first measure. Topping up from an inadequate depth (50mm or less) to 270mm of mineral wool costs £300–£800 for a typical semi-detached and can move the rating by several points for a very modest outlay. For properties already at EPC D, loft insulation alone is unlikely to reach EPC C, but it is almost always a prerequisite and is often fully or substantially funded through ECO4 or GBIS for eligible households.

Cavity wall insulation is the second most impactful measure for the majority of UK housing built between 1920 and 1990. A standard semi-detached cavity fill takes half a day and typically moves the EPC by 3–10 points. Properties with no cavity — solid brick or stone, typically pre-1920 — require external or internal wall insulation, which is considerably more expensive and disruptive. See internal wall insulation and its damp risks for the specification considerations.

Heating system efficiency is the other major lever. Replacing an aged G-rated boiler with an A-rated condensing unit adds SAP points, but not as many as moving from a gas boiler to a heat pump. Heat pumps have a Coefficient of Performance (COP) typically exceeding 2.5, meaning they deliver more than 2.5 units of heat per unit of electricity consumed. The SAP methodology reflects this. As the electricity grid decarbonises, heat pump SAP ratings improve further in future SAP updates without any physical change to the installation.

Solar PV generates a significant SAP improvement for properties with suitable roof orientation, adding estimated generation that offsets consumption. A 4kW system facing south at 30–45 degrees pitch can add 5–15 SAP points. However, solar PV does not reduce fabric heat loss and is not a substitute for insulation.

The Retrofit Funding Landscape

ECO4 obligates large energy suppliers (British Gas, E.ON, EDF, Octopus, and others) to fund retrofit works for fuel-poor households — those on means-tested benefits or referred through local authority flex routes. ECO4 covers insulation and heating upgrades. For eligible customers, works can be fully or heavily subsidised. Tradespeople access ECO4 by working through a Managing Agent holding a supplier obligation, or by partnering directly with a supplier. TrustMark registration and PAS 2030/PAS 2035 compliance are mandatory.

GBIS (Great British Insulation Scheme) targets properties in Council Tax bands A–D (A–E in Scotland and Wales) rated EPC D–G. It funds single-measure insulation improvements and is simpler to navigate than ECO4. Both schemes run through the same energy supplier obligation mechanism.

Boiler Upgrade Scheme (BUS) provides a £7,500 grant toward an air source heat pump or biomass boiler. The grant is claimed by the installer — who must hold MCS (Microgeneration Certification Scheme) accreditation — not the homeowner. The property must have a valid EPC with no current recommendations for loft or cavity wall insulation that have not been acted upon. This effectively means a heat pump installation often goes alongside addressing those insulation recommendations first.

PAS 2035 framework applies to all publicly funded retrofit projects. A Retrofit Assessor produces a full property assessment including ventilation, moisture risk, and structural condition. A Retrofit Coordinator oversees the project design, installer appointment, and handover documentation. Installers must hold PAS 2030 accreditation for the relevant measure. Tradespeople with Gas Safe, NAPIT, or NICEIC registration are already familiar with scheme accreditation; PAS 2030 follows the same model with additional documentation requirements.

What the 2030 Target Means for Landlords

If the EPC C requirement is enacted in secondary legislation — which remains the likely outcome given the strength of government policy signals — landlords will face a hard deadline. The proposed structure is:

The 2028 new-tenancy trigger is the most commercially significant near-term date. Landlords re-letting a void property from 2028 will need a current EPC C to market it. For properties that need EWI or IWI to reach the required standard, the procurement, design, and installation process can span 3–6 months. Combined with compressed installer availability as the deadline approaches, there is a strong commercial case for landlords to commission work in 2026–2027.

For tradespeople, the most effective position is to help landlords understand what their current EPC says — particularly the recommended improvements section in the full DEA report — and to quote for those specific works. The DEA's recommended improvement list is an independent assessment that functions as an informal specification and provides both landlord and tradesperson with a clear brief.

Qualifications and Business Preparation

For tradespeople wanting to access ECO4/GBIS work ahead of the private demand surge, the preparation pathway is:

  1. Register with TrustMark — free, requires adherence to the TrustMark Code of Conduct and consumer protection obligations
  2. Obtain PAS 2030 certification for relevant measure(s) through an approved certification body (CIGA for cavity wall, Kiwa or BBA for other insulation measures)
  3. Partner with an ECO4 Managing Agent or GBIS delivery chain to receive referrals

For heat pump installation specifically, MCS certification is required in addition to TrustMark. MCS covers design calculations, system sizing, F-gas handling where applicable, and commissioning documentation. The accreditation process is more demanding than standard domestic installation schemes but opens access to the BUS grant mechanism.

Frequently Asked Questions

Does a tradesperson produce the EPC?

No. EPCs are produced exclusively by Domestic Energy Assessors (DEAs) accredited through government-approved bodies including Elmhurst Energy, Stroma, and ECMK. The tradesperson carries out physical improvement works; the DEA assesses the property before and after and issues the certificate. A tradesperson cannot certify the EPC impact of their own work.

Can I guarantee a customer their property will reach EPC C?

No, and tradespeople should be clear about this. SAP scoring depends on the entire property, and the final certificate is the assessor's output based on a whole-building model. You can advise that a specific measure typically adds a given number of SAP points for a property of this type and construction, but the actual outcome depends on the full assessment. Promising a specific rating creates legal exposure and is practically unreliable.

Do the EPC C requirements apply to owner-occupiers?

No. The MEES regulations and the proposed 2030 target apply only to privately rented properties. Owner-occupiers have no legal obligation to meet any minimum EPC standard, although ratings affect mortgage availability — some lenders offer preferential green mortgage rates for EPC A/B properties — and increasingly affect resale values.

What is the penalty for a landlord letting below the minimum rating?

Under the current EPC E minimum, fines reach up to £30,000 per property for breaches exceeding three months. When the EPC C requirement is enacted, equivalent enforcement through local authorities is expected. The civil penalty is in addition to any inability to let the property legally.

How long does it take to get a new EPC after improvement works?

A DEA assessment can be commissioned as soon as works are complete — there is no mandatory waiting period. A typical house assessment takes 1–2 hours on site; the certificate is normally issued within 24–48 hours. Landlords should commission a reassessment promptly after works are finished, before re-marketing the property, to update the official rating.

Regulations & Standards