Building regs

[saint]

I can't find this anywhere. Is there minimum distances pv can be fitted on the ridge, side and bottom of a roof?
Thanks

 

[JulianC]

For your usual domestic installations I remember reading some guidance somewhere that stated that the PV should be mounted in from the edge of a roof a distance of 3 x the distance it sits above the roof. The NICEIC crappy PV course mentions 300mm all round and that's what I tend to stick to (modules sit about 100mm above the roof anyway, so it sort of ties in nicely). All to do with the wind whipping up the back of the array and trying to pull the roof off. Apparently our German friends tend not to bother and my gaffer saw plenty of systems out there mounted right to the edge and even overhanging the ridge tiles!!!

 

[dansk]

Also for permitted development im sure its no higher than 200mm from the ridge.

 

[TedM]

Permitted development is a max of 200mm perpendicular above the slope of the roof and no part can be higher than the highest part of the roof excluding chimney.

 

[Energetic]

From: The Town and Country Planning (General Permitted Development) (Amendment) (England) Order 2008


Permitted development

A. The installation, alteration or replacement of solar PV or solar thermal equipment on—

(a)a dwellinghouse; or


(b)a building situated within the curtilage of a dwellinghouse.

Development not permitted

A.1. Development is not permitted by Class A, in the case of solar PV or solar thermal equipment installed on an existing wall or roof of a dwellinghouse or a building within its curtilage if—

(a)the solar PV or solar thermal equipment would protrude more than 200 millimetres beyond the plane of the wall or the roof slope when measured from the perpendicular with the external surface of the wall or roof slope;


(b)it would result in the highest part of the solar PV or solar thermal equipment being higher than the highest part of the roof (excluding any chimney);


(c)in the case of land within a conservation area or which is a World Heritage Site, the solar PV or solar thermal equipment would be installed—

(i)on a wall or roof slope forming the principal or side elevation of the dwellinghouse and would be visible from a highway; or

(ii)on a wall or roof slope of a building within the curtilage of the dwellinghouse and would be visible from a highway; or


(d)the solar PV or solar thermal equipment would be installed on a building within the curtilage of the dwellinghouse if the dwellinghouse is a listed building.

Conditions

A.2. Development is permitted by Class A subject to the following conditions—

(a)solar PV or solar thermal equipment installed on a building shall, so far as practicable, be sited so as to minimise its effect on the external appearance of the building;


(b)solar PV or solar thermal equipment shall, so far as practicable, be sited so as to minimise its effect on the amenity of the area; and


(c)solar PV or solar thermal equipment no longer needed for microgeneration shall be removed as soon as reasonably practicable.

 

[njcuk]

Seems conflicting information on this and other threads, but I have always thought 200mm. Can anyone confirm this for sure?

 

[JulianC]

No conflicting information, just confusion in terminologies.

200mm is the max distance the panels can sit above the roof surface, in the same plane as the roof surface.

Not the same as the distance of the panels in from the edges of the roof, whether that be from the ridge, eaves or gables - for this distance there is no hard and fast rule, although the recommendation from a variety of sources (NICEIC, C&G etc.) is 300mm.

 

[mmccx]

also any closer to the roof edges and you will struggle taking any tiles out to fix the hooks. You also DO NOT want to disturb the concrete ridge or edge tiles!

 

[MCS Renewables]

Apparently you can do what you want !

anyone for a free motorcycle shelter .....Appalling Solar PV installations - Part 1 : Solar Panels & Photovoltaic Cells

 

[Zach Halley]

Is it 3 x the distance from roof to the face of the panels or 3 x the distance to the rear of the panel? There's about a 35 - 50 mm difference that will change the calculated distance a lot!

 

[Worcester]

Don't know where you got those figures from, the reasons for the spaceing from the edge are

a) Practical
b) Structural.

We generally work on 450mm from the edge / ridge / eaves

Ridge: The third row of tiles is the first one that you can move to insert a roof hook without damaging the ridge tile bedding, also the panels must not be higher that the ridge (planning rules)

Edge, it is at least the third tile in that you can lift / move as with the ridge without damaging the edge tile mortar bedding, additionally the closer to the edge you go the more wind uplift you have to consider, so the greater the forces on the rafter / truss / purlin.

Eaves, to close to the eaves and a) rain water will run off the panels and miss the gutter and b) as for the edge you will get much greater uplift forces.

 

[SolarCity]

We generally work on 300mm. However, with deep tiles (pan tiles for example), you can't even get 300mm from the ridge without disturbing the ridge tiles. We generally fit 500mm from a ridge.