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 1 October 2026. Ofgem cap for 1 October to 31 December 2026 applied (gas 7.97p, elec 26.32p, gas standing 29.68p, elec standing 54.83p). Next scheduled review 25 November 2026 (January cap announcement). [ref M5.1]
By Oliver Wakefield-Smith, Founder, Digital Signet. Corrections to oliver at digitalsignet dot com.