BUILDING REGS CHANGES
How the new building regulations affect windows and glazing
We would like to update everyone with the current information available on the new Part L and Part F Building Regulations which come into effect from 15th June 2022.
These are the first steps towards the introduction of Future Homes Standard in 2025 where building in general will need to meet new high standards.
The new regulations comprise five new documents, with Part L and Part F affecting glazing.
PART L :
HEATING & ENERGY
Currently, U-Values for new-build windows are 1.4W (m2K) and 1.0 – 1.4 (m2K) for doors depending on glazing.
Part L 2022 will require new build to achieve 1.2 W/(m2K) for windows and 1.0 W/(m2K) for doors*.
Replacement windows and doors (existing buildings) will require 1.4 W/(m2K)
*1.0 Opaque doors (less than 30% glazed area, 1.2 for glazed doors (more than 60% glazed area)
These figures are based on desirable values inputted into a SAP calculation when Building Regulations calculate the ‘notional building’. They are used in conjunction with other calculations within the building to allow for flexibility in the building design.
The ‘notional building’ is a digital representation of the actual building and uses fabric values provided by the government through Building Regulations.
These values are entered into the SAP calculations ie. thermal properties, space heating and air tightness. These are compared to the ‘notional building’ and if a window does not meet 1.2 a limiting value can be applied and other areas of the building can be improved to offset the difference.
It will be more difficult to use this option as all energy efficiency rating calculations have changed.
New U-Values will be more difficult to achieve but calculations are not based on individual products
Consideration must also be given in Part L to the fitting of frames to ensure they maintain an air barrier by use of air sealing tape. Compressible seals or gun grade sealant may be used to supplement the taping.
It is the installers responsibility for compliance to the Building Regulations
PART F :
VENTILATION
The new regulations will require most windows and doors to have trickle vents dependant on room type, volume of windows and doors fitted and if sufficient proof can be provided that the installation does not make the ventilation any worse.
Existing windows with trickle vents already in place
• Replacement vents cannot be smaller than the existing being replaced
• If the vent size in the windows being replaced is not known then the following should be used
1. Habitable rooms and Kitchens equivalent area of 8000mm2
2. Bathrooms equivalent area of 4000mm2
3. Vents must be controllable
Replacement windows that do not have existing trickle vents should be installed as below
• Habitable rooms and kitchens equivalent area of 8000mm2
• Bathrooms equivalent area of 4000mm2
If the building has continuous mechanical extract ventilation
• Trickle ventilators with a minimum equivalent area of 4000mm2 should be used in any replacement windows which are not in wet rooms (eg bathrooms, kitchens and utility rooms)
If it can be demonstrated that they comply with the requirements, ‘other ventilation provisions’ may be used
With the change to Part F regulations, approximately 90% of replacement windows will require trickle vents from 15th June 2022
To aid compliance with our current range of windows and doors, we have added as standard (unless otherwise requested) shoot-bolt locking, hinge claws, high security locks. We will now (within the next few weeks) add one or two trickle vents to sashes on each frame (unless otherwise requested) in readiness for 15 June 2022 deadline.
Please note: Aluminium windows and doors will be addressed shortly following a recent seminar and updates by ALUK and we will keep you informed
Table 1.7 minimum equivalent area of background ventilators floor natural ventilation
| Room | Minimum equivalent area of background ventilators for dwelling with multiple floors | Minimum equivalent area of background ventilators for single storey dwellings |
|---|---|---|
| Habitable room (2)(3) | 8000mm2 | 10,000mm2 |
| Kitchen (2)(3) | 8000mm2 | 10,000mm2 |
| Utility room | No minimum | No minimum |
| Bathroom(4) | 4000m2 | 4000mm2 |
| Sanitary accommodation | No minimum | No minimum |
NOTES:
1. The use of this table is not appropriate in any of the following situations and expert advice should be sought.
• If the dwelling has only one exposed façade.
• If the dwelling has at least 70% of its openings on the same façade.
• If a kitchen has no windows or external façade through which a ventilator can be installed.
2. Where a kitchen and living room accommodation are not separate rooms (i.e. open plan), no fewer than three ventilators of the same equivalent area as for other habitable rooms should be provided within the open-plan space.
3. The total number of ventilators installed in a dwelling's habitable rooms and kitchens should be no fewer than five, except in one-bedroom properties, where there should be no fewer than four.
4. If a bathroom has no window or external façade through which a ventilator can be installed, the minimum equiva- lent area specified should be added to the ventilator sizes specified in other rooms.