There is a strange anomaly in the householder planning system.
HOUSES have permitted development rights but FLATS do not.
So HOUSES can be extended without the need for planning permission, but FLATS cannot.
Since 2008, permitted development rights have become increasingly generous, meaning HOUSES can be extended in ways that Councils would never normally give planning permission for.
This means that in a row of terraced properties, the HOUSES may be extended in ways that converted FLATS right next door can only dream of.
The classic case is the dormer loft extension, whereby the rear roof of the building is squared off to provide another floor. Permitted development rights allow full-size dormers as long as a 20cm setback is provided from the edge of the roof and there is an increased volume of no more than 40/50 cubic metres. On a standard terraced HOUSE, that’s a pretty big loft.
On a converted FLAT, perhaps located right next door to a large loft extension on a HOUSE, this kind of extension is not possible. Most councils require that the dormers take up less than half the roof and are set away from all sides.
HOUSES can also be extended at ground floor level by up to 6m (subject to the light touch neighbour notification scheme). An extension of this size is virtually impossible on a FLAT.
If you have a HOUSE, but your permitted development rights were removed by condition when your property was granted planning permission, you have the same problem as FLATS.
In the West London boroughs close to our offices, the guidance on lofts is pretty similar. Ealing, for example, recommends that lofts should be modest in size and set in 0.5m from all four sides.
There seems to be little to justify this anomalous system and the householder planning system as a whole is due for an overhaul, particularly where permitted development and householder planning meet.
In the meantime, if you are considering a loft conversion or single-storey rear extension (whether to your HOUSE or your FLAT), get in touch with our lovely planning consultants for some informal, up-to-date advice.