UK Renovation Budget Planner
Estimate central heating, gas combi boiler replacement and heat pump installation costs in pounds sterling (GBP) with regional UK Gas Safe installer labour factors.
UK Cost Benchmarks
Average installed costs across typical specifications. Figures include materials and standard UK tradesperson labour.
| Specification / Option | Typical UK Fitted Range | Characteristics & Considerations |
|---|---|---|
| Direct Combi Boiler Swap (Gas) | £3,200 – £4,500 fitted | Replacing existing combi in same location with flue and chemical flush |
| System to Combi Conversion | £4,200 – £6,500 fitted | Removing hot water tank and cold cistern, replumbing pipework |
| Air Source Heat Pump (ASHP) Installation | £8,500 – £14,000 fitted | Low-carbon heating, includes cylinder, radiator upgrades, eligible for BUS grant |
HomeProjects.money editorial team reviewed this page on 6 August 2026. HomeProjects.money is an independent planning tool, not a contractor, surveyor or building-control body. Listed sources inform the context and checking process; calculator ranges remain editorial planning assumptions that must be tested against written local quotes.
Planning assumptions
A complete standard replacement system with normal controls and commissioning. Heating and cooling equipment should be selected from a heat-loss or load calculation, not by copying the old unit's label. Distribution, controls, electrical supply, ventilation and commissioning frequently determine the real project scope.
Oversized equipment can cycle inefficiently and undersized equipment may not maintain comfort. Insulation, glazing, airtightness, climate and occupancy affect the design load.
Radiators, pipework, ducts, returns, zoning and airflow balancing may need alteration even when the main appliance is replaced.
Electrical upgrades, condensate, flues, gas work, refrigerant lines and smart controls require compatible design and qualified trades.
Scope decisions
Cost comparisons are useful only when every contractor prices the same performance, preparation and finishing requirements.
Can limit disruption when the distribution system is sound and a new load check supports the approach.
Requires careful load, emitter or duct, electrical, hot-water and outdoor-unit assessment rather than an appliance-only quote.
Appropriate where comfort problems, additions, poor zoning or obsolete distribution make simple replacement a false economy.
Country requirements
The calculator never mixes UK and US prices. The guidance below also follows the selected country; local authorities and code officials remain the definitive source.
Boiler replacements require Gas Safe certification and Building Regulations compliance notification. Heat pumps can be installed under Permitted Development in England provided MCS microgeneration standards are met.
Looking for US project planning in USD? Browse our US States & Cities Cost Directory or review our US Home Improvement Planning Guides.
Quote checklist
Common questions
No. Correct sizing, distribution, controls and commissioning matter more than maximum nameplate capacity.
The base range assumes normal connection work. Major replacement, resizing or zoning needs a separate measured scope.
No. The estimator is pre-incentive because programmes, tax treatment and eligibility change by location and date.
Sources and checks
These sources support regulatory and market context. They do not publish the calculator's exact range and are not presented as contractor quotations.