Replacement Windows and Doors - building regulations

Since April 2002, all replacement glazing has come within the scope of the Building Regulations. This means anyone who installs replacement windows or doors has to comply with new thermal performance standards. (Just replacing the glass is exempt).

When the time comes to sell your property, your purchaser's surveyors will ask for evidence that any replacement glazing installed after April 2002 complies with the new Building Regulations. There are two ways to prove compliance:

1. a certificate showing that the work has been done by an installer who is registered under the FENSA Scheme

2. a certificate from the local authority saying that the installation has approval under the Building Regulations.

The FENSA Scheme

The FENSA scheme allows window and door installation companies that meet certain criteria to self-certify that their work complies with the Building Regulations. It was set up by the Glass and Glazing Federation, in association with all key stakeholders, and meets with central Government approval. A sample of the work of every installer is inspected by FENSA appointed inspectors to ensure standards are maintained and installers who fail to perform can be suspended or even excluded from the scheme. FENSA also inform local authorities of all completed FENSA installations and issue certificates to householders confirming compliance.

Any installation done by a firm which is not registered by FENSA, including work done as a DIY project by a householder, needs full local authority approval under the Building Regulations. You should note that you, as the house owner, are ultimately responsible for ensuring the work complies with the Building Regulations.

Building Regulations for windows and doors

All replacement windows in both domestic and commercial buildings come within the scope of the Building Regulations. Anyone who installs replacement windows, doors, roof lights and roof windows will have to comply with strict thermal performance standards.

How do I get approval?

Apply to us for Building Regulation approval. This would involve your installer completing a straightforward application form. We make a charge for this service, and your application should be lodged with us at least 48 hours before the work is started.

Installation of replacement windows, doors and rooflights Building Notice Form

Or, your installer may be a registered member of a self-certification scheme known as FENSA. For further information about FENSA approved contractors, please visit the FENSA website .

Do I have to use PVCu windows?

No, you can install wood, metal or PVCu windows providing they are draught-proofed and give reasonable thermal insulation

Do I have to double glaze?

Yes, unless the building is an historic building and you must replace the windows to match the existing to comply with Planning Legislation.

Do I have to use special double-glazing?

Yes, you must use a low emissivity glass such as Pilkington K on the inner pane. The air gap between the panes of glass must be at least 16mm

I don't want to use low E glass, what can I do?

You may be able to use triple glazing, i.e. three panes of glass

What about conservatories?

The glazing in conservatories does not need to be low E glass if the conservatory is separated with a wall and a door from the rest of the house. The heating in the conservatory must have separate heating controls from the rest of the house.

When do I have to use safety glass?

Safety glass, toughened or laminated must be used in all doors. Also all windows within 800mm of the floor must be safety glass to cope with the weight of someone falling against it, further measures may be necessary to deal with the risk of anyone falling from low level window openings

How can I tell if it is safety glass?

The manufacturer will have put a small symbol on the glass

Do I have to have opening windows?

The room will need ventilation, so an opening window is needed. The opening window needs to be at least the size of the existing opening or not less than 1/20th of the floor area of the room. You also need to put in ventilation for any gas fires or boilers in the room. Check to see if the room already has airbricks installed, otherwise you will need to put in some fixed vents in the windows. It is also necessary to have "trickle ventilators" to avoid condensation

What other things do I need to consider?

You need to talk to the Building Control Officer about fire safety and means of escape in case of fire. You may need to have "means of escape windows" especially upstairs or from rooms that do not have direct access to a hallway or external door.

You need to consider the means of cleaning the windows - can a ladder be used outside by a window cleaner, or will "tilt and turn windows" be better.

Do the regulations apply to new doors?

The same regulations apply if more than half of the door and frame, including the fanlight, is glazed. Any glazing in the door or door side panel should be safety glass, unless the panes are less than 250mm wide.

Care must be taken with the threshold of the door. An upstand can be particularly difficult for people with wheelchairs and pushchairs. Many modern homes have a ramped or level entrance and in these cases a door threshold with an upstand should not be used.