Permitted Development - Side Extensions

[Randomiser]

I wonder if anyone can help with a query on permitted development rights for side extensions.  I have looked at both the Technical Guidance for Householders (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/830643/190910_Tech_Guide_for_publishing.pdf) and the underlying legislation (http://www.legislation.gov.uk/uksi/2015/596/made) and in both cases I think they are saying the same thing, but my conclusion surprises me, so I thought I would check to see if I am missing something.

 

I am looking at A.1. (j) from the Act which says:

 

Quote

(j)the enlarged part of the dwellinghouse would extend beyond a wall forming a side elevation of the original dwellinghouse, and would—

(i)exceed 4 metres in height,

(ii)have more than a single storey, or

(iii)have a width greater than half the width of the original dwellinghouse;

 

What I expected was that the total width of side extensions would be limited to half the width of the original house.  But that does not appear to be what it is saying, if it were would it not refer to the enlarged parts of the dwellinghouse?  By treating them as singular it suggests (to me at least) that each individual extension needs to comply with the three tests.  In the case of a detached house does that mean an extension of 50% of the width of the house can be built?  If the intension was to limit the total width of the house after permitted development extensions to 150% of the original width why not just say that?  The technical guidance only shows semi-detached examples, so it is no help in answering this question.

 

Has anyone ever come across this question and or point being tested?  Has anyone seen a situation where permitted development rights on both sides of a house has been successful?

 

Many thanks in advance,

Randomiser.

Edited October 22, 2019 by Randomiser

[Ed Davies]

Doesn't this depend on what they mean by “enlarged part”?

 

I'd assume that if you have a 10 metre wide house then you can add a 3 metre extension on one side then extend that by another 2 metres but not add a 5 metre extension then later another 5 metre extension beyond that so it must mean at least the total amount of extension on one side of the house. But is it the total amount of extension on both sides? From the way it's worded I'd assume not (so you could add 5 metre extensions on both sides if it was detached) but the interpretation section doesn't help make that clear.

[Randomiser]

22 minutes ago, Ed Davies said:

Doesn't this depend on what they mean by “enlarged part”?

 

I'd assume that if you have a 10 metre wide house then you can add a 3 metre extension on one side then extend that by another 2 metres but not add a 5 metre extension then later another 5 metre extension beyond that so it must mean at least the total amount of extension on one side of the house. But is it the total amount of extension on both sides? From the way it's worded I'd assume not (so you could add 5 metre extensions on both sides if it was detached) but the interpretation section doesn't help make that clear.

That is exactly how I read it Ed.  If you go either side both are individual extensions and can therefore each be up to half the width of the original house.  I had just assumed that it would be the total additional width, but that does not appear to be what it says.

[bassanclan]

If both sides of a semi can put a side extension on, there no reason why a detached house couldn't on both sides

[Temp]

If I remember correctly side extensions can only be single storey and less than 4m high within 2m of the boundary. 

[Randomiser]

1 hour ago, Temp said:

If I remember correctly side extensions can only be single storey and less than 4m high within 2m of the boundary. 

Only 4m high anywhere and eaves max 3m within 2m of any boundary.

[Randomiser]

1 hour ago, bassanclan said:

If both sides of a semi can put a side extension on, there no reason why a detached house couldn't on both sides

That is a very logical observation.  Not that planning is always logical of course ?