A PAS 2035-aligned budget for a sequenced retrofit. Fabric-first ordering, BUS grant included, and a realistic stage breakdown so you don't buy a heat pump for a leaky house.
Estimates the realistic budget for a whole-home retrofit — fabric first, services second — and shows the order to do them in. Uses PAS 2035 staged approach.
A retrofit done in the wrong order is one where you buy a heat pump for a leaky house. We use the standard fabric-first sequence: airtightness + insulation → ventilation → heat → renewables. Costs are 2026 mid-range trade pricing.
Home
Current state
Goal
Result
Tell us about your home
Terrace
Semi-detached
Detached
Bungalow
Pre-1919 (solid wall)
1919-1944 (mostly cavity)
1945-1980 (cavity)
1981-2002
2003+ (modern)
Current state of the home
A
B
C
D
E
F
G
Don't know
None
Some (<200mm)
Full (≥270mm)
None
Cavity wall filled
Solid wall — uninsulated
Solid wall — externally insulated
Solid wall — internally insulated
Gas combi (≥10 yrs old)
Gas combi (<10 yrs)
Oil
LPG
Direct electric
Heat pump (existing)
What's your goal?
Comfort + cheaper bills
Make it heat-pump-ready
Net-zero (full retrofit)
EPC C (mortgage requirement)
All at once (12 months)
Staged (3-5 years)
Opportunity-led (next decade)
How we model this. Costs follow PAS 2035 / EST 2024 mid-range trade pricing for England/Wales. Heat pump cost includes BUS grant (£7,500 deduction). MVHR/MEV cost banded by property type. Annual saving estimated from EPC uplift bands (E→C ~30% heating saving). 25-year lifetime applies a 1.4× multiplier for energy inflation. This is NOT a quote. Get a PAS 2035 retrofit assessment for your specific home before committing to anything beyond stage 1.