Working file M5.1
Smart thermostat retrofit cost (UK 2026)
Tado, Nest, Honeywell Evohome installed cost ranges in 2026, plus where load compensation actually saves on a heat pump.
Cost in 2026
Smart thermostat installed cost in 2026. The published installed range in 2026 is £350 to £950 supplied and fitted (publisher rates from Tado and Honeywell ranges; MCS-compatible controls). Both ends of that range are stated rather than collapsed to a midpoint, because the spread reflects real differences in scope, access and grant eligibility rather than installer mark-up.
What drives the spread
- Hardware: single zone vs multi-zone Evohome.
- Boiler / heat-pump compatibility plug-ins (OpenTherm vs eBUS).
- Smart-meter linkage and weather-comp curve setup.
- ECO4 measure-table eligibility where coupled with a heating change.
Where it sits in the PAS 2035 sequence
Set at the same time as the heating change, not bolted on later.
Surveyed 22 June 2026. Ofgem Q3 2026 cap applied (gas 7.33p, elec 26.11p, gas standing 29.04p). Next scheduled review 26 September 2026 (Q4 cap publication). [ref M5.1]
By Oliver Wakefield-Smith, Founder, Digital Signet. Corrections to oliver at digitalsignet dot com.