ECO4 (Energy Company Obligation) is a government scheme requiring large energy suppliers to fund insulation and heating improvements for low-income households. To qualify, you must: own your home (or be a private tenant with landlord consent), have an EPC rating of D, E, F, or G, and receive certain means-tested benefits (e.g., Universal Credit with relevant component, Income Support, Pension Credit). The scheme covers free or subsidised insulation measures including cavity wall, loft, and room-in-roof insulation.

Cavity walls have two brick layers with a gap between them — this gap can be filled with insulation (typically mineral wool or foam beads). Solid walls have no cavity and are thicker; they require either external or internal wall insulation systems. Solid wall insulation is more expensive (£8,000–£15,000+) but can achieve better results. Properties built before 1920 typically have solid walls; post-1920 properties usually have cavity walls. Cavity wall insulation costs £400–£1,500.

Yes. Uninsulated lofts lose around 25% of a home's heat. Adding 270mm of loft insulation is one of the most cost-effective energy improvements available. It costs £300–£600 for a typical semi-detached home and can save £135–£250 per year on energy bills. Even top-up insulation from 100mm to 270mm provides meaningful savings. Loft insulation should be combined with insulating the water tank and pipes in the loft.

Savings depend on property size, current insulation levels, and heating system. Typical annual savings: loft insulation (270mm): £135–£250/year; cavity wall insulation: £135–£260/year; solid wall insulation: £235–£490/year; room-in-roof insulation: £125–£225/year. These figures are from the Energy Saving Trust and assume a gas-heated semi-detached home. Older, larger, or detached properties typically save more.

EPC ratings run from G (worst, most expensive to heat) to A (best). From April 2018, landlords cannot let properties below EPC E. By 2030, privately rented properties must achieve EPC C. The average UK home is rated D. Improving from EPC E to EPC C is an achievable target for most properties through insulation, glazing, and heating improvements. The cost of upgrading depends on the property's current condition.

It is usually better to insulate and heat the main house properly before extending insulation to the conservatory. If you use your conservatory year-round, solid or tiled roof insulation can make it more comfortable and reduce heat loss. However, an uninsulated conservatory acts as a buffer zone — insulating it fully changes this thermal dynamics. Always ensure adequate ventilation to prevent condensation.