Single Storey Extension Roof Pitch PD Query

[RichA[2]]

Hi,

I my trying to help my mother who wants to do a rear extension under PD.
She has an CoL for an extension with a flat roof; but now wants to proceed with a pitched/crown roof.

She would like something similar to image below: proposed extension in Blue; proposed roof in Red; proposed flue in Lime
(extension would be <4m deep, with eaves <3m high, total height <4m, it is within 2m of the rear boundary)

- Are there any restrictions to doing a Crown Roof under PD? I can't see anything in the Guidance.

- If she was to go with a pitched roof; would it have to match the existing? And which of the existing pitches (as the front has two pitches)?
[the steeper pitch would be too steep as it would make the extension roof higher than 4m]

- Are there even any restrictions on the pitch of a single storey extension?

- Finally (!), are there any restrictions to moving the chimney flue into the new extension; and on its height.

Many thanks.

 

[RichA[2]]

I have been through the existing (flat roof) LDC and these appear to be the key PD questions; I can't see any reason why any of the answers change by adding a Crown Roof (as per image in OP).

Class A
C~ Would the height of part of the dwelling house enlarged, improved or altered exceed the height of the highest part of the roof of the existing dwelling house? No
D ~ Would the height of the eaves of the part of the dwelling house enlarged, improved or altered exceed the height of the eaves of the existing dwelling house? No
E ~ Would the enlarged part of the dwelling house extend beyond a wall which – (i) Forms the principal elevation of the original dwellinghouse; or (ii) Fronts a highway and forms a side elevations of the original dwellinghouse No, the extension would be to the rear of the property
F ~ Subject to paragraph (g), would the enlarged part of the dwelling house have a single storey and – (i) Extend beyond the rear wall of the original dwelling house by more than 4 metres in the case of a detached dwelling, or 3 metres in the case of any other dwellinghouse, or (ii) Exceed 4 metres in height? No, the proposed extension on the detached dwelling would extend exactly 4m.
H ~ Would the enlarged part of the dwelling house be within 2 metres of the boundary of the curtilage of the dwelling house, and the height of the eaves of the enlarged part exceeds 3 metres? No, the extension would sit 1.5m from the boundary line but only have an eaves height of 2.45m.

A.3 Conditions:
Proposals permitted under Class A must also comply with the following conditions:-
(a) The materials used in any exterior work (other than materials used in the construction of a conservatory) shall be of a similar appearance to those used in the construction of the exterior of the existing dwellinghouse  The submitted plans detail that matching materials would be used
(b) Any upper-floor window located in a wall or roof slope forming a side elevation of the dwellinghouse shall be – (i) Obscure-glazed, and (ii) Non-opening unless the parts of the window which can be opened are more than 1.7m above the floor of the room in which the window is installed  The proposal is for a single storey extension only – N/A
(c) Where the enlarged part of the dwelling house has more than a single storey, or forms an upper storey on an existing enlargement of the original dwellinghouse, the roof pitch of the enlarged part must, so far as practicable, be the same as the roof pitch of the original dwellinghouse.  The proposal is for a single storey extension only – N/A

 

[^woody^]

A combination roof can be done under PD, as long as it meets the general roof criteria. A first storey roof does not need to match the pitch of the main roof, however whether that will look odd is another matter. The type of tiles will govern the required pitch.

A flue more than 0.99m above the roof will not be PD.

A new LDC will be required the design is being altered.

 

[RichA[2]]

A combination roof can be done under PD, as long as it meets the general roof criteria. A first storey roof does not need to match the pitch of the main roof, however whether that will look odd is another matter. The type of tiles will govern the required pitch.

A flue more than 0.99m above the roof will not be PD.

A new LDC will be required the design is being altered.

Many thanks Woody.

She wants to proceed quite quickly (and the council are very slow) so will move forward without an LDC if it should meet all PD requirements; which it appears it does.

Re: chimney, this will be as shorter than in image above. I think 0.99 should be fine for building/flue regs.