Under Building Regulations Part L (England and Wales), zoning is required in new dwellings with a floor area over 150m², with a minimum of two independently controlled heating circuits (typically separating upstairs sleeping areas from downstairs living areas). For smaller homes, a single zone with room thermostats and TRVs (Thermostatic Radiator Valves) on radiators is still required for efficiency.
Zoning means that a home’s heating system is divided into independently controlled areas, allowing each zone to be heated to different temperatures at different times. For example, living areas may require heating during the day while bedrooms only need warmth in the early morning and evening.
The benefits of zoning are:
- Energy efficiency: heating only occupied spaces when needed.
- Comfort: different temperatures in different parts of the home.
- Cost savings: reduces unnecessary energy usage.
Scotland and Northern Ireland follow similar zoning requirements aligned with a strong focus on reducing energy consumption.
With modern insulation and airtightness in newbuilds, zoning ensures heating systems operate efficiently, aligning with the UK’s net zero goals while providing homeowners with better control over comfort and energy bills.
A zoned heating system requires reliable, compliant controls to ensure efficient and effective operation. These include:
Room thermostats
- Required to control each zone independently
- Programmable for time and temperature schedules
- Can be wired or wireless, and smart thermostats add further flexibility
Zone valves
- Motorised valves (typically two-port) controlled by thermostats
- Open/close to direct flow to specific zones based on demand
TRVs (Thermostatic Radiator Valves)
- Required on radiators in rooms without a thermostat
- Allow fine-tuning of room temperatures
Time controls/ programmers
- Set heating schedules for each zone to match occupancy patterns
Smart Controls
- Multi-zone smart systems can automate heating based on presence, weather compensation and remote control
- Ensure efficient boiler or heat pump operation, reducing cycling and optimising flow temperatures.
With heat pumps:
- Advanced controls are recommended to maintain low flow temperatures while allowing temperature adjustments for different zones
- Weather compensation and load compensation help maximise efficiency
By ensuring the correct controls are specified and installed, heating engineers and contractors can deliver systems that comply with Building Regulations Part L, enhance energy efficiency, and provide optimal comfort for homeowners.