Is a Hip to gable loft conversion allowed under PD?

26 Feb 2010
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United Kingdom
I am keen to know your opinions on this. I have a 3 bed semi detached house with no alterations to the original building and want to add a hip to gable loft conversion with a rear dormer. I've been looking into the Permitted Development conditions and am still not clear if my interpretation of this limit is accurate.

"An extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway is NOT permitted development."

I understand that to comply with PD the additional roof space must not exceed 50m3 and that it is not possible to extend beyond the plane of the existing roof slope on the principal elevation (i.e. a dormer on the front). Is a continuation of the existing plane, as would occur when changing from hip to gable, the same as an extension beyond the plane?

I'd be grateful for your opinions or experiences with this,
Thanks, John
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My personal opinion would be your proposal would not fall within PD because the hip to gable conversion is (as you say) happening on the principal elevation, which in effect, you're increasing the volume of the roof space by the addition of what "looks like" a dormer.

Once others have had a chance to look and reply, there's no harm in you approaching your LA to ask the question. Like normal, they'd probably ask for a sketch and that will not be difficult to put together. And at least that way, they'd give you their view (at officer level and not that of the council) and then any other factors that may influence the design (e.g. conservation area, designated land and even if the PD rights have been removed from your property).
Thanks for your response.

I see your point, but the mini guide is unclear on the planning portal. When I read it and view the illustration, it is clear to me that anything which projects past the slope (ie towards the highway, as in a dormer) is not permitted development.

What it doesn't make clear is if it is acceptable to continue the slope for a hip to gable conversion. This would mean surely that nobody who lives in a semi detached or terrace property would be able to carry out a hip to gable conversion under PD, as this type of conversion would always need to continue the slope.

Also none of the others factors you mention would influence the design as they are not applicable in my case.

Sounds to me like you're outthinking yourself. (if that makes sense) Keep it simple.

Changing a hipped roof to a gabled roof is permitted providing you do not change the plane of the roof on the principle elevation. (which you would not do in a normal hip to roof job)

Adding a dormer to the rear roof is permitted providing it is not the principle elevation. Just stay within normal dormer rules and you're OK.

Apply a 50m² maximum to the overall end result.

So it's permitted.

Where you need to be careful is on corner plots where the gable would face the highway. As long as that doesn't apply you are safe.
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Thanks John

I am just trying to get my head around this as I know that if we went for full planning, the local authority would probably say no, as they are reluctant to grant permission for this type of conversion.

You sound like you have some experience in this field. Have you converted a loft recently?

How about going for your basic intention but add a small hip to the gable to keep planning happy?

You might get away with that.
I've not done one myself but I can assure you they are permitted and many have been done since the new rules.

Local authorities hate them and have tried their best to find a way to stop them. A number of certificates of lawfulness have been refused for various reasons. What the local authortiy are trying to achieve is if they can get an inspector to dismiss one for some reason. This would then give them grounds to refuse certificates and issue enforcements on ones that are proceeding.

I read recently of one case for a hip to gable that was refused a year or two ago. The applicant went to appeal and it was dismissed. So that was that. But when the new rules appeared they applied for a certificate of lawfulness, which was refused. And then went to appeal again, and that was allowed.

If you are still unsure you can apply for a certificate of lawfulness. Or alternatively a pre-application opinion - but that has no legal standing so it is ONLY the opinion of the officer.
Im going through this myself and I only submitted a Lawful Development Certificate application. Several of my neighbours have done theirs too and I can see they did the same, none of them got full planning permission.

I was told by planning that as long as you dont change the front elevation (or that facing the highway) by adding a dormer etc you are OK. The dormer on the rear of mine and the hip to gable are under PD as long as its within 50m2.

Hope that helps - my scaffolding is going up on Friday and I am still waiting for the certificate!
definately go for the Certificate of Lawfulness as if nothing else , you will have a piece of paper that has legal standing when you come to sell the property. Another point that if you should be in a conservation area then the rules may be quite different.
I'm a bit late on this but it is PD, there's amended info on the P Portal
BUT planners don't like it, nor full width flat roofed dormers, and they will atempt to resist. Prepare for fireworks
BUT planners don't like it, nor full width flat roofed dormers, and they will atempt to resist. Prepare for fireworks
I can only totally agree :!:

Edit: I have started a new thread as this may have otherwise been easily missed. See Volume calculations - advice required

Hopefully someone will be able to help me. We have planned to have a hip to gable with rear dormer loft conversion done under the permitted development. I have we'll read up on the technical guidance document and my understanding was that my proposed works was covered under PD provided not in conservation or green belt area and we do not exceed the 50m sq rule.

To formally check we were not in a conservation area I submitted a permitted development enquiry (£65) to the local authority, with all the details and sketches of the work.

To my surprise they replied stating that planning permission is required under Class B1(b) due "to the enlargement the roof space on a principal elevation that fronts a highway". I should say here that the principal elevation is the front of the house, it is not a corner plot.

I have rang and disputed this with the planning liaison officer my arguments being:
1. The roof space is being extended to the side elevation, not the principal elevation.
2. The plane of the existing roof slope on the principal elevation is not being altered, merely extended along to the gable.
3. Condition B.2 (b)(i) makes reference to a hip to gable conversion thereby implying that it is by default covered under PD.

He still disagrees, but advised me to write in with my arguments, which I will do. I have a feeling they are just trying to force me down the planning route so they can formally reject it, as it will imbalance the look of the two semis. I am after some advice really on my options if they stick to their guns.

1. If I had not made the PDQ enquiry and just gone ahead with it, can they do anything about it? Would it end up in court?
2. Does anybody have prior experience of this and the process to get formal approval under PD without going to planning

Your help much appreciated

From your description your dormer will be on the gable elevation not facing a highway. As long as you are certain the front of the house is the principal elevation then get on and build your dormer. You don't need any pieces of paper from the council. If you proceed they might initially follow it up but just ignore them. They will eventually take the trouble to look into it properly and then realise they are wrong.
Hip-to-gables are permitted development, as long as the gable does not form the principal elevation, and as long as the property is not on article 1(5) land etc.

It is pointless applying for a LDC for one of these, still less formal planning permission. Aside from the cost, many planning officers are as thick as two short planks and don't understand the legislation they are supposed to be interpreting. This is why several contributors to this thread have had different responses from their LPAs.

Once more; Hip-to-gables are permitted development: Full stop.[/i][/b]

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