Windows and Building Regulations

New windows bring several great benefits to any home, like helping you to save on your energy bills and improving the comfort of your home.

One of the most important things you need to do when altering or installing new windows is to make sure you adhere to window Building Regulations.

Whether you seek building regulations approval yourself or not, it’s worth knowing what Building Regulations are and how they apply to your windows.

What are Building Regulations?

Building regulations are a set of design and construction requirements that most buildings need to meet. Their goal is to ensure the health and safety of everyone in and around these buildings. They’re also designed to make sure that buildings are relatively energy efficient, and meet the needs of people with disabilities.

Do Building Regulations apply to windows?

Building Regulations do apply to windows. Your windows need to meet certain standards in 4 different areas:

1. Heat Loss

New window glazing and frames need to be good heat insulators. This will reduce the amount of heat that escapes from your home and lower your energy bills. If you want to install new windows, they need to be at or below a certain level of energy efficiency, which is measured as a U-level. For more information on this maximum U-level, take a look at Approved Document L-1B, Table 1, of the Building Regulations.

2. Safety Glazing

Windows in certain areas of your home have to be fitted with safety glazing. These include any windows that are:

  • Below 80cm from floor level
  • 30cm or less from a door and up to 150cm from floor level
  • Within any glazed door up to 150cm from floor level

So any new windows you install need to be safety glazed in these areas.

3. Ventilation

All rooms in a property should have sufficient ventilation, and windows are part of ensuring this. In some rooms smaller windows and trickle ventilators are enough. But in rooms where large amounts of steam are produced, like kitchens and bathrooms, a certain amount and size of windows and extractor fans are required.

4. Fire Safety

There are 2 ways in which windows have to promote fire safety. Some windows close to other properties need to have fire resistance and be fixed shut in order to avoid the potential spread of fire between buildings. Which windows these are depends on how close your property is to another building.

New windows also need to be considered as fire exits. If you’re replacing a window that is big enough to be a means of escape, then the new window also has be big enough for this, even if it might actually be a bit smaller than the original window. Escape windows should have:

  • A width and height of at least 45cm
  • A clear openable area of at least 33cm square
  • A cill no higher than 110cm from the floor

You don’t normally need more than one escape window per room.

How can I comply with Building Regulations?

You have 2 options when it comes to complying with Building Regulations and applying for approval if necessary. You can:

1. Hire a ‘competent person’

If you hire a contractor who’s on the Competent Persons Register, they’ll make sure than any window work they do complies with Building Regulations. They have the power to self-certify their work, and will contact your local authority if approval is needed. When the work is complete, they will give you a certificate to say all the work complies with Building Regulations.

2. Use a building control body

If you don’t hire a ‘competent person’, you can use a building control body. Building control bodies (BCBs) can be either run by your local authority or privately. If you use a BCB they will check if your planned window work complies with Building Regulations, and apply for approval for you if necessary. When your window work is finished, they’ll provide you with a certificate which proves it’s all in line with Building Regulations. To find either a local authority or private BCB you can use the government’s Planning Portal website.

As with anything you don’t want to fall foul of the law. With windows, if you fail to adhere to Building Regulations then you risk needing to remove the full installation, which nobody wants. So to be on the safe side, you should make sure you use one of the two options above.

To learn more about regulations that may apply to your window work, take a look at our information on planning permission. Or to find out about possible window options, see our information on uPVC, wood and aluminium frames.

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