There is no set number of times you can extend your home. Some properties we have worked on have already had multiple extensions built in the past but the layouts of these do not work for the current owners. In some cases additional bedrooms or home offices are required which could be achieved with a first floor addition above an existing garage or previously built extension.
Loft conversions can be built under permitted development guidelines which may not have been an option in the past. Over time our day-to-day requirements from a property change, in the past there was a push for an increased number of rooms whereas now there is a greater focus on open plan living.
There are a lot of properties that have had previous extensions built, particularly loft conversions, that at the time were approved under a householder planning application. In a lot of cases the scale of these had to be limited to reduce the bulk and mass of the extensions, you will see a lot of homes that have converted the existing loft space and inserted rooflights or small dormers into the roof slopes.
Now a large percentage of loft conversions will be designed to comply with permitted development where the main focus is matching materials, ensuring the ridge height is not increased and making sure you do not exceed the volume requirements. On a typical three-bedroom semi-detached house it is possible to re-design the roof and build a large dormer to create an impressive master suite.
One of the common requirements for extensions is that they do no breach a 45-degree line drawn from the centre of the nearest neighbouring window, there will likely be some dimension set by the local authority for the depths of extensions but it can be possible to extend past these limits if it can be proved that you will not impact on the neighbours.
Another option with the planning on homes that have already been extended is to look at prior approval, which is an extended form of permitted development, a detached house under permitted development can be extended by 4m from the rear wall of the original house, on semi-detached and terraced properties you can extend out 3m.
Here is an example of a build project which included an extension on a home that had already been extended
During our first consultation with clients a commonly asked question is ‘our house has already been extended 50% of the footprint, does this mean we can’t extend further?’ under permitted development guidelines this used to be one of the main requirements but under the new rules each extension is covered under its own set of guidelines and there is no limit to the amount of extensions you have providing that you meet all the constraints.
We have worked on homes that have had a ground floor extension or conservatory which we have proposed to remove and rebuild an extension larger than what had existed. These applications will often be submitted under a householder planning application, there is more emphasis on the size of the extension and the impact it will have on the look of the existing property but also the effect it has on neighbouring properties light along with outlook.
This home in Surbiton had an extension on a home that had already been extended by us in 2017
Under the Prior Approval scheme these distances can be increased to 8m on a detached and 6m on the other types. With the permitted development applications these can be built without the need of any planning permissions, but we would always recommend applying to the council for a Lawful Development Certificate, so you have proof that the extension is lawful which is helpful if you sell the property.
With extensions that fall within the prior approval distances you will have to seek permission before you build, it is really important to seek advice before building an extension to ensure that the works do comply with all the requirements set out in the permitted development technical guidance. If the extension is built and the council are informed that there is a breach it will likely result in retrospective planning applications being needed. In the worst-case scenarios extensions have had to be reduced in size to comply with the local authority’s policy on depths of extensions.
