When you decide to get your extension built you will probably choose your doors and windows based on whether they fit in with your existing home and by how thermally efficient they are. You may give very little thought into whether these choices will affect your requirement for Planning Permission. But if you make the wrong choice you may find yourself having to go down that route.
For the vast majority of cases, you will not usually need to apply for Planning Permission for the doors and windows on a permitted development extension. If the extension itself has been carefully planned to avoid planning then you are normally home and dry. If you stick to the following rules, your chances of needing planning are greatly reduced.
- You are simply repairing or maintaining the existing windows – you may do this as part of a general refurbishment during your extension build
- The new doors and windows look similar to those already on the house
- Side windows are made from obscured glass, if they face towards neighbours
- Upper windows need to be at least 1.7 metres above floor level or non-opening
Roof lights or skylights
If you want to add a skylight to your extension you can normally do so without the need of Planning Permission as long as they protrude no further than 150mm beyond the roof slope, they are no higher than the current roof and the adhere to the obscured glass and opening restrictions detailed above.
When will I need Planning Permission?
In some cases, your new extension may not be eligible for permitted development because it is too large or your home is listed or in a conservation area. If this is the case you may need to apply for Planning Permission that will include some restrictions on the type of windows and doors used. This will also apply if you live in a flat.
Doors and windows, whether replacement or new are almost always subject to buildings regulations approval. These rules ensure that you meet the regulations surrounding thermal performance, safety, air flow and fire escape rules. If you use a builder who is part of the Competent Person Scheme, they will ensure you comply with the guidelines and will be able to provide a certificate to show the work was carried out correctly.
If you do it yourself you will need to get a buildings regulations inspector out to check the windows and the work. They will then issue you with a certificate.