Building & Other Regulations / Restrictions
As a FENSA registered company, Installations 4U is authorised to certify that installations of windows and doors comply with relevant Building Regulations. Non-FENSA registered contractors and homeowners installing windows and doors on a DIY basis must first apply for Building Regulations approval from their local council.
For full details of the FENSA scheme, and the non-FENSA requirements, visit www.fensa.org.uk.
Disclaimer
The following information is intended only as a layman's guide to those parts of the Building Regulations that apply to the replacement of windows and doors in domestic dwellings under normal circumstances. Links are provided to contact the statutory authorities controlling Building Regulations and Planning Permission.
The information was reviewed and correct as at 01/04/2002 (the introduction date of Approved Document L1, Conservation of fuel and power in dwellings) and is based on the law as it applies to England and Wales. Similar but different regulations apply in the Channel Islands, Eire, Northern Ireland and Scotland.
In all cases your first point of contact should be your local authority.
As well as complying with the relevant Building Regulations, you must check your property deeds for any restrictive covenants. If you are a leaseholder, or your property is a flat with a shared freehold, you must get the freeholder's permission before starting work. For flats with shared freeholds you will almost certainly have to comply with restricted design and colour options (usually to match the originals), and sometimes with restricted material options, such as timber only.
Listed buildings and conservation areas
Additional regulations apply to replacing windows and doors in listed buildings and conservation areas.
A listed building is protected by law, and Listed Building Consent must be obtained before any changes are made. Carrying out unauthorised work to a listed building is a criminal offence punishable by a fine or a prison sentence, and the local council can require you to put the building back as it was.
If your property is in a designated conservation area (covered by an Article 4 Direction), planning permission must be obtained before windows or doors are replaced. Work without permission may lead to an Enforcement Notice from the local authority. If the work was carried out acceptably, a retrospective planning application will usually be invited. If not, reinstatement (rarely practical) or replacement with approved products will be required. Failure to comply with an Enforcement Notice is a criminal offence.
Always check with your local authority Building Control department before starting work of this type. Responsibility for compliance lies with you, the householder, not the contractor. To find your local authority, go to www.lga.gov.uk and search from there.
Building Regulations summary for replacement windows and doors
L1: Conservation of fuel and power in dwellings
Approved Document L1, effective from 1 April 2002, introduced the requirement that all replacement window and door installations must have Building Regulations approval from your local council.
The main thrust of L1 is compliance with strict legal requirements for the conservation of fuel and power in dwellings. This is achieved by limiting heat loss through windows and doors, requiring them to meet set levels of insulation (thermal transmittance). Thermal transmittance, the U-value, measures how much heat passes through one square metre of a window or door when the air temperatures on either side differ by one degree. The lower the U-value, the better the insulation.
uPVC replacement windows and doors must have a U-value of 2.0 or less.
N1: Glazing safety in relation to impact
Approved Document N, Part N1, deals with protection against impact, defining areas of critical (high risk) glazing and the type of glass to use there. Glazing that people are likely to come into physical contact with must either break safely if broken on impact, resist impact without breaking, or be shielded or protected from impact.
High risk areas are:
- Windows where the bottom of the glass is within 800mm of floor level
- All glass within doors, from floor level up to a height of 1500mm
- All glass within door side panels, and windows adjoining doors, from floor level up to 1500mm and to a width of 300mm
Safe breakage is defined in BS 6206:1981, paragraph 5.3. In practice, compliance is achieved by using toughened or laminated safety glass to BS 6206 in all critical areas.
Although not specifically covered in Document N, windows next to baths or showers, and windows on stairs or landings, should also be considered critical areas if there is any risk of impact. Safety glass may look a slightly different tint to normal glass because of the manufacturing process, so good industry practice is to fit safety glass in every pane of a door or window that needs any safety glass.
Replacement windows and doors must comply with the sections above. For the sections below, replacements must be no less suitable than the existing windows and doors.
B1: Fire safety
For a typical domestic dwelling (storeys not more than 4.5 metres above ground level), Approved Document B requires all habitable rooms (living rooms and bedrooms, but not bathrooms or kitchens) on and above the first floor to have emergency egress. Ground floor rooms whose only fire escape is through another room also need suitable escape windows.
An external door (above ground floor) or window used for escape should have an unobstructed openable area of at least 0.33 square metres, at least 450mm high and 450mm wide, with the bottom of the openable area no more than 1100mm above the floor (section 2.11 of the Document). In practice this is achieved by fitting an Egress brand fire escape hinge to a designated casement opening in each habitable room on and above the first floor.
Because of the original construction of some properties (particularly post-war bay fronted houses) it is not always possible to meet the section 2.11 specification, which was introduced in 2000.
Senior representatives of FENSA, GGF and BBA have agreed their understanding that where a window used as a means of escape is replaced with the same proportional fenestration (the same transom, mullion and sash layout) in modern materials, the casement openers may create a slightly smaller aperture because of larger sections. In their opinion, such a window will still be acceptable to FENSA as a fire escape provided it has a modern fire-escape type hinge allowing the window to open fully to 90 degrees. This applies only to refurbishment work, and the three organisations were to discuss it with the appropriate authorities.
F1: Ventilation
Approved Document F1 sets requirements for the type and amount of ventilation. Replacing like for like in the amount and size of opening casements, top-lights and sashes will usually comply. If replacements are not like for like and openings are reduced, measurements and calculations are needed to comply with the table below.
| Room | Rapid ventilation (e.g. openable window area) | Background ventilation (trickle vents) |
|---|---|---|
| Habitable room | 1/20th of the floor area of the room served | 8000mm² |
| Kitchen and utility room | Opening window (no minimum size) | 4000mm² |
| Bathroom and shower room | Opening window (no minimum size) | 4000mm² |
| Bathroom and shower room | 1/20th of the floor area of the room served | 4000mm² |
Where alterations are made, such as replacing a door and side window with a patio or French door, an approved type and size of trickle ventilator in the head of the new door will achieve compliance. The same applies if a door being replaced provides the only ventilation in a room.
K2: Protection from falling, collision and impact
For replacement windows, Approved Document K requires restrictor stays to limit the opening of casements and sashes in windows above the ground floor that are within 800mm of floor level.
A1: Structure
Approved Document A (structure) will not usually apply to replacement windows and doors. However, installers must make sure all work meets all relevant Building Regulations, and the contractor should assess the suitability of the support or lintel above the replacement window or door.
Bay window replacements must not compromise the load bearing ability of the bay, so all appropriate poles and spreader plates must be in place. Depending on the original construction and current condition of some bay windows, the head (top section of frame) should be propped and left in place during replacement to prevent structural movement or collapse.
If there is a structural alteration, for example replacing a lintel, you will need approval from your local authority Building Control department.
Health and safety legislation
All work must comply with statutory health and safety requirements to protect the health, safety and welfare of operatives, customers and members of the public. Examples include:
- Safe handling and removal from site of all debris, especially broken glass
- Protecting passers-by when working above public thoroughfares, with scaffolds, netting, signs and look-outs
- Appropriate safety equipment when working above first floor, such as harnesses, scaffolding, safety cradles and lifting devices
Building Control and Planning Permission
Windows and doors for any new construction must comply with all of the above, including extensions to existing dwellings and forming new door or window openings within the original building. Planning permission may be required, and you will always need approval from your local authority Building Control department. To find your local authority, go to www.lga.gov.uk. Copies of the regulations can be obtained from HMSO at www.thestationeryoffice.com.
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