With the long-term aim of achieving the ‘Future Homes 2030’ standard, UK Building Regulations will be undergoing a major change. The Government is initially targeting new construction to achieve a ‘Zero carbon’ target for sustainable construction by 2030 through a planned ongoing series of incremental changes to the building regulations.
The first of these comes into effect on the 15th June 2022, with the tightening up of the Part L (conservation of fuel and power) and F (Ventilation) regulations. It also introduces two new sections to the regulations: Part O (addressing overheating) and Part S (electric vehicle infrastructure). Changes are in progress for parts Q (security), M (access to and use of buildings) and J (Combustion appliances and fuel storage systems). Further changes will follow in 2025, prior to the full Future Homes regulations being adopted in 2030.
How might this affect you? Well, from June, any construction project that has not already been approved under the current existing regulations will be assessed under these new regulations. Projects that have been approved prior to this date under the current regulations will need to be commenced within 12 months to be considered under those regulations. Unlike previous transition periods, the ‘start on site’ will apply only for individual buildings under construction. This means that if a development of two or more buildings is proposed, works have to start on all buildings within the 12-month period in order to be assessed under the current regulations.
The Part L regulations are being tightened to increase insulative properties and air tightness. At it’s most simple, the U-values which assess the thermal transference of a building element are becoming more stringent, as shown on the table below. The current air change rate of 10m3/(h.m2) will be also be reduced with all new buildings to undergo air testing to confirm this.
Target (W/m2K) | ||
U-values | 2016 | 2022 |
Walls | 0.30 | 0.18 |
Roof | 0.20 | 0.11 |
Floor | 0.25 | 0.13 |
Windows | 2.00 | 1.2 |
Doors | 2.00 | 1.2 (glazed) 1.0 (opaque/ semi-glazed) |
Additionally, greater stress is being applied to the continuity of thermal insulation. This means that in the case of junctions between elements (for example window to wall or wall to floor) evidence will be required to show that cold bridging has been minimised as far as practical.
The intention is for gas boilers to be phased out of the UK heating market after 2025. Greater weight will be given to high efficiency alternatives to traditional heating systems, such as heat pumps, renewables, and district heating. For the first time, waste-water heat recovery (WWHR ) can be included in the SAP (Standard Assessment Procedure) calculations and both PV (Photo-Voltaic) and indeed WWHR systems are more likely to be required in order to obtain a good pass. The SAP assessor will be wanting specific details on many other elements including shower flow rates and lighting efficacy.
Limiting values for new fabric elements in existing dwellings. |
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Target (W/m2K) | ||
U-values | 2016 | 2022 |
Walls | 0.28 | 0.15 |
Roof (pitched, insulation at ceiling) | 0.16 (pitched roof, insulation at ceiling level) | 0.15 |
Roof (pitched insulated between rafters) | 0.18 (pitched roof insulation at rafter level or flat roof with integral insulation) | 0.15 |
Roof (flat integral insulation) | 0.18 (pitched roof insulation at rafter level or flat roof with integral insulation) | 0.15 |
Floor | 0.22 | 0.18 |
Windows | 1.4 (or EPC rating B minimum) | |
Doors | 1.4 (or EPC rating B minimum) | |
Swimming Pool Basin | 0.25 | 0.25 |
Limiting values for upgrading existing elements in existing dwellings. | ||
Walls – Cavity insulation | 0.70 threshold/ 0.55 Improved | |
Walls – internal/ external insulation | 0.70 threshold/ 0.30 Improved | |
Roof (pitched, insulation at ceiling) | 0.35 threshold/ 0.16 Improved | |
Roof (pitched insulated between rafters) | 0.35 threshold/ 0.18 Improved | |
Roof (flat integral insulation) | 0.35 threshold/ 0.18 Improved | |
Floor | 0.70 threshold/ 0.25 Improved |
In parallel with this will be the introduction of the new regulation restricting overheating as well as looking to avoid the installation of air conditioning to reduce energy demand. There will be a maximum limit on glazed areas to 21% of the floor area, with a minimum opening area of 12% to allow ventilation for excess heat.
In general, going forward, the construction of any new building project (including extensions to and refurbishments of existing buildings where 50% or more of a thermal element is involved) will be increasingly more vigorously monitored by Building Control. The requirement of a new ‘Building Regulations England Part L’ (BREL) guidance document will feed into an end user guide and will need to be completed with supporting photographs, ensuring that the end product delivers the design parameters targeted.