Permitted development rules for House extensions Buckinghamshire.

Property space solutions Ltd offer extensions, loft conversions and driveways. We navigate you around the planning issues and guide you on what’s accepted under ‘permitted development’ rights.

This is a basic and uncomplicated guide to Permitted development rules for House extensions Buckinghamshire.

First of all, ‘permitted development rules apply to houses and bungalows. It does not apply to flats and maisonettes.

What is ‘Permitted development’?

Permitted development was introduced by the government several years ago to speed up the process of the standard extensions householders commonly apply for. Most  extensions, namely single storey rear extensions, side extensions, loft conversions, were bogging down the Council planning department. Therefore Permitted development was born to free up the council planners to focus on bigger planning requests.

So how does ‘permitted development’ affect me?

The rules are basic and broken down into segments based on the type of house you live in.

Extensions                                                                                                                                         Loft conversions

Detached property                               8 metres                                                           50 Cubic Metres

Semi detached property                     6 Metres                                                            50 Cubic Metres

Terraced property                               6 Metres                                                            40 Cubic Metres 

It should be noted however that the government increased the size of extensions back in May 2013. Prior to this date ‘permitted development was just  3 metres for terraced and semi-detached houses and 4 meters for detached. So as you can see, the sizes permitted have doubled. The Government although not having made these generous extensions to permitted development permanent, they currently have no date in place to revert back to the original meterage.

Other factors that affect ‘permitted development’.

If your extension comes  within two meters of a boundary, the maximum  eaves height cannot be higher than three meters to in order to remain within ‘permitted development’ rights

If you are proposing a 2 storey extension then the building cannot project more than 3 metres and the extension must be in excess of 7 meters from your rear boundary

Site coverage;

You cannot build on more than 50% of the land around your property. This is based on the original house footprint built by the original developer, or if you have an older house, how your house was in 1948. This is where you calculate your permitted development extension coverage of available land.

Roof pitch

you cannot build higher than your current roof. roof pitches have to follow the line of the existing roof. it is noteworthy to add a flat roof to a single storey extension if need be.

Loft conversions are permitted a ‘dormer’ conversion but not a ‘mansard’ type roof.

Verandas are another build not included under ‘permitted development’ rights.


Finally, If you propose to have windows to the side of your property, they will need to be frosted. Otherwise windows need to be positioned at 1.7 meters above the floor. This is to protect neighbour privacy.

Contact today for advice on Permitted development rules for House extensions Buckinghamshire and get a free quote. Or call 07551756279

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