Permitted development Class E: buildings etc size

FizzerUK

Hi,

Have been reading posts and literature and tried to understand the Class E: buildings etc

I have my main things worked out.

It is within 2 meters of boundary so eves will not be more then 2.5m.
It will not be made of combustible material being metal clad on the boundary side  (whole lot will be because it is cheap TBH). I think this applies if the building is more than 15m2???
I am not in any of the special restriction areas like conservation / listed etc..

BUT.. and here I have searched re-read posts of builds on other forum's / social; media and there is such conflicting things!!

What exactly is the largest area to build.
I know it can not cover more than 50% of the area, not including the house (curtilage?).
This is not an issue having a rear garden 28m x 9m (252m2)

I have seen 2 main figures. Not bigger than 30m2 (30 square meters) or not bigger than 15m2 (15 square meters).

The only thing on government site I can find that relates to size is...

(j) the capacity of the container would exceed 3,500 litres
A container with a capacity greater than 3,500 litres will not be permitted development and will require an application for planning permission.
I "ASSUME" that this applies to containers maybe like fuel oil??

So does that apply to garden sheds?  or does it apply to things like swimming pools.
Because that would not allow for a building of 15m2 with a eves height of 2.5m2

I have seen YouTube (i know social media) of builders erecting workshops that they say are within permitted development being 6m x 4m or more (24m2)

What is the restrictions regarding size..  Just getting confused reading stuff.

My building will be.......

• Total area of 24m2, a little less in floor area
• Within the 2m boundary
• Is not over 50% of the curtilage (including other buildings of the rear)
• It will be metal clad on the boundary.
• The eves will not be above 2.5m
• Will not have any raised platform above 0.3m (I have seen a LOT of raised decks bigger than this??)
• Will be using spanning tables C16/C24 and appropriate fixings etc. to stay within building code.

Was thinking about putting in an Lawful Development Certificates (LDCs)??  Peace of mind I guess. Helps with re-sale of house????


Can anyone confirm the the actual building area restrictions?
 (I can only find, but not officially that if it is above 15m2 then boundary has to be none combustible).

Thoughts on the LDC?

Also, regarding working out the curtilage. Do you need to include a garage on the side of the property that was not part of the original build, and has had planning permission.
Assuming not as the 50% rule I think applies to the rear??  Again confused on this...

Please help / advise.

Thanks
(Stay Safe, Stay Sane)

casper_gutman

You're mixing up two things here: planning permission, and building regulations. The points you raise about C16/C24 spanning tables, appropriate fixings and non-combustible cladding facing a boundary are issues to do with building regulations and not planning.

Planning permission regulates whether the type and size of building is appropriate in terms of planning considerations - e.g., what will the building be used for? How big is it? It's entirely unconcerned with how the building is constructed. Some works are effectively pre-approved, as "permitted development", and many of the points you mention are part of deciding whether your proposed outbuilding falls in that category. You should look up the rules in your area, but the ones applicable in England are here: Permitted development rights for householders: technical guidance - GOV.UK

Building regulations control how the building is constructed. They don't care how big it is, just that it shouldn't fall down or otherwise be hazardous to people in it, and that it meets certain other requirements e.g., for insulation.

The 15 m² and 30 m² limits relate to building regulations. In England, if your proposed outbuilding is under 15 m² and doesn't contain sleeping accommodation then "building regulations will not normally apply". If it's 15-30 m² then "you will not normally be required to apply for building regulations approval providing that the building contains NO sleeping accommodation and is either at least one metre from any boundary or it is constructed substantially of non-combustible materials." More info can be found at: Is building regulations approval needed for an outbuilding? - Outbuildings - Planning Portal

casper_gutman

Oh, and the 50% area rule applies to the whole of the "curtilage" on all sides of the house. The curtilage is usually the whole area of land associated with the house: the garden, driveway, outbuildings, and the land under the house itself. If the house is built in the grounds of a larger house - e.g., an estate cottage or annex - then rules may be a bit more complicated.

To find whether permitted development applies you need to check the area of the curtilage excluding the original* house. This must be more than double the total area of existing and proposed outbuildings and any existing or proposed extensions built under permitted development or granted planning permission.

*For houses built before 1948, the "original house" is the house as it was in 1948, including any attached extensions added before that.