Solar pergola and permitted development?

[kentar]

I want to install around 20 solar panels on top of a pergola. The pergola needs to be constructed first, but i'm not sure on where I stand with planning permission and permitted development.

 

An example of the kind of thing I want.

 

 

 

A few words on the scenario:

I live on a hill, with a main road going in front of my house, and a side road that branches off to the rear of my house. My garden has a slope, roughly 600mm from the top end to the bottom end. My garage is half sunk into the ground, with a driveway that's sloped down to meet with the road behind. The height difference between my patio and the level of the road that runs behind my house is at a minimum 2m. The neighbour to the left is not attached to my property, but has a garage next to mine.

 

 

A picture explains a thousand words:

 

 

 

Firstly, permitted development allows for buildings to be erected with a max height of 2.4m. I believe that this level is taken from the highest point of the surrounding land. As the highest point is the patio, would that mean I can carry this height down the length of the garden? 

Secondly, would this structure be classed as a lean to? It will be attached to the house, although not in the traditional sense, and it won't be enclosed. If it's classed as a lean to, the allowance is a max eaves height of 3m if within 2m of a boundary. There is a 200mm height difference between the alley and the patio, which is why i've labelled it as 3.2m.

 

[Nickfromwales]

45 minutes ago, kentar said:

A picture explains a thousand words:

It would, if we knew where due South was 

[kentar]

 

 

Pic from google. Technically it's SSE, but good enough. There will be no issues with shading.

 

Edited October 9 by kentar

[DevilDamo]

Anything attached to the house would be deemed and treated as an extension, not an outbuilding.

[DevilDamo]

6 hours ago, Nickfromwales said:

It would, if we knew where due South was 

What relevance does that have to do with the OP’s question on PD?

[ProDave]

3 hours ago, DevilDamo said:

Anything attached to the house would be deemed and treated as an extension, not an outbuilding.

So if the pergola went from the outer edge of the patio and stopped just before the garage it would be treated as an outbuilding and PD rules would apply then?

 

Max height 3M at highest point.

[saveasteading]

15 hours ago, kentar said:

kind of thing I want.

That might take off on the wind.

It will need a substantial pergola, with strong connections throughout and fixed down hard to a foundation.

The sort of pergola you see in a garden centre is not made for this use. The solar panels at that angle will create a wing effect and could all end up next door.

Would this be diy or a specialist package?

[saveasteading]

8 hours ago, DevilDamo said:

What relevance does that have to do with the OP’s question on PD?

Mine hasn't either then. 

 

[saveasteading]

14 hours ago, Nickfromwales said:

It would, if we knew where due South was 

A picture saves 999 words?

[sgt_woulds]

2 hours ago, saveasteading said:

That might take off on the wind.

It will need a substantial pergola, with strong connections throughout and fixed down hard to a foundation.

The sort of pergola you see in a garden centre is not made for this use. The solar panels at that angle will create a wing effect and could all end up next door.

Would this be diy or a specialist package?

 

 

Not necessarily.  We used to build them with planters / ballast boxes at the base.  Fill with soil and plants (or gravel for that pub ashtray look!) and they won't go anywhere. 

 

Pergola and frame still needs to be strong enough to keep the panels attached, but properly bolted 4x2 is more than man enough.

 

If mounting microinverters under the pergola remember they can get very hot - keep out of reach of curious fingers

[Temp]

I think I would make sure it looks a bit less like a ground mounted array and more like a building with PV on the roof.... As I can see some jobs worth arguing it's really a ground mounted solar array which I think needs PP close to the boundary.

 

Perhaps give it two or three timber clad walls and a brick BBQ?

[saveasteading]

44 minutes ago, sgt_woulds said:

We used to build them

'We' meaning  a business with insurance?  

Yes agreed that deadweight will work too. Presumably you didn't use the cheap pergolas which form an arch and support a honeysuckle at most. I've seen skinny things made with cheap cedar.

Did you build them from 3 x 2 / 4x2 tanalised? That is the sort of structure this needs in a gale. 

 

I'm not against it, just urging caution and research.

[Nickfromwales]

17 hours ago, DevilDamo said:

What relevance does that have to do with the OP’s question on PD?

Pointless putting the solar in the shade?!

 

Plus….

 

I was curious. 🧐. So “there”. 

[sgt_woulds]

15 hours ago, saveasteading said:

Presumably you didn't use the cheap pergolas which form an arch and support a honeysuckle at most. I've seen skinny things made with cheap cedar.

Did you build them from 3 x 2 / 4x2 tanalised? 

 

 

 

Yes!  Application of common sense is required... 🙂

 

Properly designed and nicely planted they can form an attractive addition to any garden.  We actually had problems with people who wanted to close the pergola sides in, as they then required more ballast to prevent uplift.  Generally a couple of extra concrete slabs in the trough bases before adding soil was enough. 

 

Wind uplift is easy enough to calculate.  We had a structural engineer create a calculator for us that took account of average wind speeds accross the country + a margin of error for the 100 year storms that seem to happen every year now!   You can find similar calsulators free on the interwebs now.

 

When calculating the ballast, we used concrete slabs as the main ballast, with the soil (dry weight, not wet) as our margin of error.   

 

+ Pergola, PV rails, Inverter(s), water, plants, worms etc. they ain't goin' knowhere!  Plus you can easily take the array with you if you move house. 

 

This was 15 to 20 years ago when PD for solar panels was still being worked out.  We installed maybe 10 pergolas accross the country and never had any issues with gaining permission, except with West Oxfordshire Council, which was seemingly staffed by the sort of NIMBY's that make 'normal' NIMBY's groan and look away.  We had problems with every PV system we installed in their remit, ground or roof mounted!   

 

Their objection to the pergola, (with lovely green oak frame and surrounded on all sides by hedges and garden walls) was that it could be seen by someone looking out from the top of the church tower at the edge of the village...

 

[DevilDamo]

On 09/10/2025 at 09:03, ProDave said:

So if the pergola went from the outer edge of the patio and stopped just before the garage it would be treated as an outbuilding and PD rules would apply then?

 

Max height 3M at highest point.

Correct but a maximum height of 2.5m when positioned within 2m of a boundary.

[JohnMo]

Does a pergola need planning - no generally. Think most of what is posted is for a building.

 

When does a pergola become a building - when you enclose roof and sides. So now the question is does it become a building if you only cover the roof and leave all sides open? That is the question 1

 

Question 2 is, can I install solar panels at the front of my house that are not on my roof, but on a garden structure. Generally no, without prior planning permission.

 

So can you install a solar pergola at the front of your house without planning - no.

[saveasteading]

5 minutes ago, JohnMo said:

can you install a solar pergola at the front of your house without planning - no.

Agreed, it isn't really a pergola but a structure for solar panels.

[JohnMo]

2 minutes ago, saveasteading said:

Agreed, it isn't really a pergola but a structure for solar panels.

this a cut and paste out of English permitted development rights 

 

Development not permitted

B.1  Development is not permitted by Class B if—

(a)in the case of the installation of stand-alone solar, the development would result in the presence within the curtilage of more than 1 stand-alone solar;

(b)any part of the stand-alone solar—

(i)would exceed 4 metres in height [F7or, in the case of stand-alone solar on land in a conservation area which would be installed so that it is nearer to any highway which bounds the curtilage than the part of the dwellinghouse or block of flats which is nearest to that highway, 2 metres in height];

(ii)would, in the case of land F8... which is a World Heritage Site, be installed so that it is nearer to any highway which bounds the curtilage than the part of the dwellinghouse or block of flats which is nearest to that highway;

(iii)would be installed within 5 metres of the boundary of the curtilage;

(iv)would be installed within the curtilage of a listed building; or

(v)would be installed on a site designated as a scheduled monument; or

(c)the surface area of the solar panels forming part of the stand-alone solar would exceed 9 square metres or any dimension of its array (including any housing) would exceed 3 metres.

[sgt_woulds]

Sorry, I missed a word in my sentance:

 

'We installed maybe 10 pergolas accross the country and never had any issues with gaining PLANNING permission...'  

 

PD for ground mounted or wall mounted PV didn't exist back then, had to go for PP each time.  Should be much easier today.

 

PD is obviously the cheapest option, but having to get PP shouldn't cause issues unless you are in a conservation area, listed property, or have to get PP from West Oxfordshire Council!