South London homeowners can access thousands of pounds in government grants for energy improvements in 2025. A PAS 2035 retrofit assessment is the essential first step to unlocking ECO4 and Great British Insulation Scheme funding.
If you own a home in South London and are thinking about improving its energy efficiency, 2025 is an excellent time to act. Government grant schemes are still open, energy bills remain high, and a well-planned retrofit can significantly reduce your running costs while improving comfort. The starting point for almost all grant-funded work is a PAS 2035 retrofit assessment, and this is something our ABBE-accredited team carries out across Lambeth, Wandsworth, and Southwark.
A retrofit assessment under PAS 2035 is a detailed survey of your home that goes far beyond a standard EPC. While an EPC in South London gives you a snapshot energy rating from A to G, a retrofit assessment analyses the building fabric, heating system, ventilation, and how the property is used. The output is a formal Improvement Measures Report that sets out recommended upgrades in the correct sequence, ensuring they work together safely as a system.
The fabric-first principle is central to PAS 2035. This means insulation and draught-proofing should be addressed before upgrading the heating system. Installing a heat pump in a poorly insulated Victorian terrace, for example, would be both inefficient and potentially damaging. A retrofit assessment prevents costly mistakes like this.
A large proportion of properties across Lambeth, Wandsworth, and Southwark are Victorian and Edwardian terraces or converted period flats. These homes typically have solid walls rather than cavity walls, which requires different insulation approaches. They may also have older heating systems, sash windows with single glazing, and limited roof insulation. Our assessors are experienced with South London housing stock and understand the challenges these properties present.
Several government schemes remain open in 2025 and can fund significant improvement work. ECO4 (Energy Company Obligation 4), running until March 2026, provides fully funded insulation, heating upgrades, and other improvements to eligible households. Eligibility is based on means-tested benefits or a low EPC rating of D or below. A PAS 2035 retrofit assessment is required to access this scheme.
The Great British Insulation Scheme provides single insulation measures such as loft or cavity wall insulation to homes in Council Tax bands A to D, or to households receiving qualifying benefits. The Boiler Upgrade Scheme offers grants of up to 7,500 pounds towards an air source heat pump, with no income threshold - open to any homeowner replacing a fossil fuel boiler.
A standard EPC is valid for 10 years. However, if you carry out significant energy improvements, it is worth commissioning a new assessment to reflect the updated rating. The EPC cost in London in 2025 is typically between 79 and 140 pounds depending on the type, and at Carn Energy our prices are published clearly with no hidden fees.
Our ABBE-accredited assessors cover all of South London, including Brixton, Clapham, Balham, Battersea, Peckham, and Dulwich. We carry out both standard EPCs and PAS 2035 retrofit assessments, giving you a complete picture of your property and the improvements available to you. Find out more about our retrofit assessment service or check your area.
ABBE-accredited, TrustMark-registered PAS 2035 Retrofit Assessments across Lambeth, Wandsworth, and Southwark.
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Most South London homes have solid walls, not cavity walls. A PAS 2035 retrofit assessment identifies the right insulation approach and unlocks grant funding.
ABBE-accredited EPC assessments across Lambeth, Wandsworth, and Southwark.
