Retrofitting the World: Can We Fix Old Buildings Fast Enough?
The technology is not the problem. Heat pumps, insulation and electrification are proven and already deployed - and 2025 was the UK's best year yet, with 125,037 heat pumps sold, up 27% on 2024, according to the Heat Pump Association (13 February 2026).
But the government's Warm Homes Plan wants more than 450,000 installations a year by 2030 - itself a target cut by a quarter from the 600,000-a-year ambition set out in 2021. The Heat Pump Association's own analysis says reaching it needs 33% compound growth every year, far above 2025's 27%.
Behind the sales numbers sits a labour shortage: the Heating and Hotwater Industry Council calculated in January 2023 that the old target needed around 150,000 trained installers; a separate Heat Pump Association projection puts the need at 33,700 full-time installers against current ambitions. Either way, the certified workforce today is estimated at only around 10,000.
Cost is the other wall. A typical installation runs to £11,000-£13,000 before the government's £7,500-£9,000 Boiler Upgrade Scheme grant - enough to lock out any household without savings or room to borrow. And insulation, the cheaper half of the job, is further behind still: the Great British Insulation Scheme closed in March 2026 having reached 100,900 households against an original target of around 300,000.
This video traces the policy history - from Boris Johnson's 2021 Heat and Buildings Strategy through Rishi Sunak's 2023 relaxation of the off-grid boiler ban - and lays out three ways this goes by 2050: sustained acceleration, a plateau that leaves millions of homes undecarbonised, or a further policy retreat. No figure appears without its date and source.
Educational documentary. Not financial or investment advice.
Chapters
- A 29-million-home problem
- Why new is easy and old is hard
- The technology that works today
- The policy history: boilers, grants and U-turns
- 2025's record year
- Why the growth rate still falls short
- The installer bottleneck
- The cost barrier for households
- Insulation first: the other half of the job
- What "enough" would look like
- Three ways this could go by 2050
- What would change the trajectory
Sources and credits
Photo credits (Wikimedia Commons)
- Vaillant aroTherm Plus air source heat pump retrofitted on a terraced house, Southend-on-Sea: Southend-on-Sea Borough Council, UK, CC0 - https://commons.wikimedia.org/wiki/File%3AAir_Source_Heat_Pump_-_Vailliant_aroTherm_Plus_on_a_terraced_house.jpg
- Air source heat pump outdoor unit: Wikideas1, CC0 - https://commons.wikimedia.org/wiki/File%3AHeat_pump_unit.webp
- Large air source heat pump outdoor unit: Wikideas1, CC0 - https://commons.wikimedia.org/wiki/File%3ALarge_heat_pump_setup.webp
- Air source heat pump mounted on a balcony/wall: Wikideas1, CC0 - https://commons.wikimedia.org/wiki/File%3AHeat_pump_on_balcony.jpg
- Wiring and indoor connections for a heat pump's external heat exchanger unit: Wikideas1, CC0 - https://commons.wikimedia.org/wiki/File%3ALarge_heat_pump_setup_2.webp
- Late-1950s terraced houses, Paddockhurst Road, Gossops Green, Crawley New Town: The Voice of Hassocks, CC0 - https://commons.wikimedia.org/wiki/File%3ACrawley_Housing_-_Terraced_Houses_in_Paddockhurst_Road%2C_Gossops_Green.JPG
Primary sources
- Heat Pump Association, 'UK Heat Pump sales reach record high in 2025, but more must be done to meet Government targets', 13 February 2026 - the 125,037 figure, 27% growth, UK manufacturing share, and the 33% compound-growth calculation.
- UK Government (Department for Energy Security and Net Zero), Warm Homes Plan technical annex, published 21 January 2026 - the 450,000-a-year-by-2030 target.
- UK Government (then Department for Business, Energy and Industrial Strategy), Heat and Buildings Strategy, published 18-19 October 2021 - the 2035 gas-boiler phase-out ambition and the original £5,000/£6,000 Boiler Upgrade Scheme grants.
- UK Government press release, 'PM recommits UK to Net Zero by 2050 and pledges a fairer path...', 20 September 2023 - the £7,500 grant increase and the off-grid oil/LPG/coal boiler ban delay from 2026 to 2035.
- CIBSE Journal, 'Warm Homes Plan cuts heat pump target by 25%', January 2026 - the comparison between the 2021 and 2026 targets.
- Heating and Hotwater Industry Council (HHIC) Systems Group research, reported 17 January 2023 (e.g. Specification Online, 'Demand for installers is main barrier to 2028 heat pump target')
- Heat Pump Association, workforce projection report, 2024.
- MCS (Microgeneration Certification Scheme) contractor data, 2024, reported by Cooling Post and pv magazine - the ~5,000 certified contractor businesses and the ~10,000-installer estimate.
- Energy Saving Trust consumer guidance, and UK Government Boiler Upgrade Scheme statistics, 2025/26 - the £11,000-£13,000 typical installed cost.
- Ofgem, Boiler Upgrade Scheme guidance, 2026 - the £7,500/£9,000 grant amounts.
- gov.uk, 'Summary of the Great British Insulation Scheme: May 2026' - the 100,900 households and 139,200 measures final figures.
- edie.net and Utility Week, 2023 coverage of the Great British Insulation Scheme's July 2023 launch - the ~300,000-household original target.
- 3Keel, Global Retrofit Index (commissioned by Kingspan), 2022/2023 interim report.
Not regulated financial advice.