Start with your own certificate
Do not begin with a generic list of upgrades. Find the property's current certificate and read its recommendation report. The recommendations are specific to the features recorded by the assessor and show a modelled score after each step.
First check that the description is accurate: floor area, wall construction, glazing, heating system, controls and insulation can materially affect the assessment.
A sensible decision sequence
- Confirm the problem — check the certificate, recent bills, comfort issues, damp or ventilation concerns.
- Reduce avoidable heat loss — consider draughts, accessible insulation and heating controls where appropriate.
- Plan fabric and ventilation together — insulation and airtightness work can change moisture and ventilation behaviour.
- Review the heat source — only after understanding heat demand, emitters, controls and hot-water needs.
- Consider generation — solar electricity can improve the score, but roof suitability, shading and household use still matter.
- Reassess when useful — a new EPC is needed if you want the official register to reflect completed work.
Low-disruption checks
- Replace remaining inefficient fixed lighting.
- Understand and programme heating controls correctly.
- Check accessible loft insulation depth and condition.
- Draught-proof appropriate gaps without blocking required ventilation.
- Insulate an accessible hot-water cylinder where the existing insulation is inadequate.
These measures are not equally valuable in every home. The certificate and a competent installer should guide the choice.
Larger measures need design, not guesswork
Cavity-wall, solid-wall, floor and roof insulation can be effective but must suit the construction and exposure. Window replacement may improve comfort but is not always the first or most cost-effective route to a better score. Heat pumps require proper heat-loss calculations, emitter sizing and controls.
For older or traditionally constructed buildings, seek advice from someone who understands moisture movement and ventilation. A poorly designed retrofit can create condensation, mould or fabric damage.
Grants and finance change
Schemes, eligibility and funding levels change. Use the current GOV.UK energy-efficiency service rather than relying on an old article or a contractor's generic claim.
Before approving work
- Get a written scope and performance assumptions.
- Check installer accreditation where a scheme requires it.
- Confirm planning, listed-building, building-control, lease or freeholder requirements.
- Ask how ventilation and moisture risk have been addressed.
- Keep invoices, guarantees, commissioning records and photographs.