Considerations for kitchen and bathroom windows

When replacing windows, it’s easy to forget that some rooms in the home should be treated differently to others.

Kitchens and bathrooms are unique in that more moisture is produced in these rooms than any others and therefore special consideration must be given to:

• Ventilation
• Meeting building regulations
• Additional measures for preventing damp.

Ventilation

According to Planning Portal, the general rules for ventilating a room are as follows:

Purge

This is achieved by opening the window. The opening should have a typical area of at least 1/20th of the floor area of the room served, unless it is a bathroom which can be any openable size.

Trickle ventilation

This can be incorporated in to the head of the window framework, or by some other means. The area varies with the type of room:

• Habitable room - 5,000 mm² equivalent area
• Kitchen, utility, bathroom (with or without WC) - 2,500 mm² equivalent area

Both these forms of ventilation are normally required, however alternative approaches to ventilation, such as mechanical extractor fans, may also be acceptable but would need agreement from the building control body.

Meeting building regulations

With any home alteration, including replacing windows, it’s important to check you are meeting the government’s building regulations. For kitchen and bathroom windows, these will mainly concern maintaining adequate ventilation to maintain indoor air quality.

The building regulations around ventilation in England can be accessed here.

If you’re adding new windows to your kitchen or bathroom, such as a rooflight, which will in theory create extra ventilation, you should firstly check whether you need planning permission, in addition to checking whether you’ll be meeting ventilation requirements.

Tips for preventing damp

Condensation is the most common form of damp to be found in the home – particularly in kitchens and bathrooms, where moisture is often in the air from cooking, running the washing machine or dishwasher, and showering or bathing.

If not addressed, condensation can create mould growth, which can lead to health issues, not to mention causing damage to walls and looking unsightly.

So here are some small measures you can take to reduce condensation levels in your home: