Flat roof or pitched roof?

[BruceB]

I have been asked to quote for about 7 kW PV on a single storey commericial building in a town. The x4 roof areas all slope at about 10 degrees to the horizontal. It has many characteristics of a flat roof rather than a pitched roof (no apex). No time for planning permission so want to meet non-domestic PD rules. A pitched roof means I can come 200 mm from surface; a flat roof means I can come a metre above, which might be useful for an east/west array.

Has anyone seen any guidance on (or got any experience of) how sloping a roof has to be to no longer be considered flat under SI 2012/748?

 

[Gavin A]

0-10 degrees is classified as flat in HSE guidance, so I'd go with that in the absence of anything else.

 

[Bryan McGrory]

Hi Bruce,

Any roof with a pitch less than 5 degrees is considered flat in the BSEN1991 and the BS6399 therefore the roof with a 10 degree pitch is a pitched roof.

If you need any structural reports (includes static, wind & snow loads) please do not hesitate to contact us.

Kind Regards,

Bryan McGrory
BMG Surveys Ltd
BMG Surveys Ltd. - Home
0141 532 2322

 

[Somecamel]

I was under the impression that commercial installations were not covered under permitted development rights?

 

[Worcester]

They are permitted development and have been since March 2012, subject to 50kWp limit and other parameters.

On 25th March 2015, non-microgeneration (>50kW) then also got a load of dispensations and so also got permitted development, subject to a load of conditions.