Independent savings figures for smart thermostats, weather compensation, and zoned smart-TRV setups. Based on the BEIS Smart Heating Controls trial — not vendor marketing.
Calculates realistic savings from smart heating controls — programmable thermostats, zoning, TRVs, and load compensation. Based on independent BEIS/EST trials, not manufacturer marketing.
Smart thermostats save money by improving control fidelity, not by magic. The savings come from: (1) avoiding overheating empty rooms, (2) load compensation reducing boiler cycling losses, (3) better setback compliance.
Home
Current
Upgrade
Result
Your home and bill
Heating only — exclude hot water and cooking if possible.
1
2
3
4
5+
≤6 hrs (work full-time)
~12 hrs
18+ hrs (WFH / retired)
What controls do you have now?
Manual stat (no programmer)
Basic programmer + room stat
Programmer + some TRVs
Full TRVs (no smart stat)
Basic smart stat (Hive/Nest)
What are you considering?
Basic smart stat (Hive/Nest)
Smart stat with load comp (Tado, Honeywell EvoHome)
Smart stat + smart TRVs (zoned)
Weather-comp + smart stat
Hive/Nest: £180–£280 · Tado V3+: £200–£300 · EvoHome multi-zone: £700–£1,500 · Smart TRVs: £55 each (8 rooms ~£500). Add £100–£200 for installation if not DIY.
How we model this. Baseline = manual thermostat (no programmer). Upgrade saving fractions follow the BEIS Smart Heating Controls Field Trial 2018 (mean 13% over basic programmer for advanced smart stat with self-learning + geofencing) plus EST 2024 update for weather/load compensation (16%) and zoned smart-TRV (18% on irregular-occupancy homes). Occupancy multiplier reflects diminishing returns when the home is occupied >16 hrs/day. Cumulative saving uses 3%/year energy inflation. These figures assume a properly commissioned setup — the savings disappear if you set the schedule once and never tune it.