What type of loft conversions need planning permission?

Whether you are dreaming of adding a bedroom, bathroom or an extra chill out space, there are lots of different options for loft conversions and while all of them need to comply to building regulations, not all will require planning permission. In terms of the build and the adjustments to the roof, which type of loft conversion you go for will impact planning permission requirements. 

Dormer loft conversions

Extending vertically from your existing roof slope, a dormer loft conversion doesn’t usually dramatically change the exterior of your home, so in most cases you won’t need to apply for planning permission and the work will fall under permitted development. To ensure that this is the case, the extension will need to be set at least 20cm back from the original eaves and the height should not reach any higher than the original roof, otherwise planning permission will be required. 

Hip-to-gable loft conversions

Through straightening the sloping side of your roof, a hip-to-gable loft conversion creates a vertical wall. While that might sound like a dramatic change, because the height of the roof doesn’t increase, this will usually come under a permitted development, but it is worth checking that your specific conversion does not exceed these rules. 

Mansard loft conversions

Through raising the pitch of your roof until it’s almost vertical and the top is flat, a mansard loft conversion dramatically changes the shape of the roof structure, so will generally need planning permission. 

How long does planning permission take?

If you are based in England, you can apply for planning permission through the planning portal. 

Your local planning authority is obliged to let you know their decision on your work as quickly as possible. If the work is straightforward then as quickly as possible should be no longer than eight weeks. If it’s a more complex or larger application, it may take up to 13 weeks, and up to 16 weeks if an Environmental Impact Assessment needs to be carried out. 

Just because you have the planning permission in place doesn’t mean that you have to get to work straight away. Most planning permission notices are valid for up to three years and the work can be completed after the time period has expired. This can also be beneficial if you are planning to sell, as you have permissions in place for new property owners. You will receive a letter of approval detailing the length of time that planning permission covers.

If you would like to talk through the requirements of your loft conversion and the different options available to you, please get in touch.