Planning Question: Flat roof extension & eaves

bemak · 21-02-2016 12:58pm #1

Generally for single storey extensions under 40sqm to qualify as exempted development the following must apply (according to CoCo)

What height can I build my extension without permission?

(a) The highest point to which the wall of an exempt extension can be built is
eaves level.

(b) If the proposed extension has a flat roof, it must not exceed the eves or
parapet level.

(c) If the proposed extension has a pitched roof, it must not exceed the ridge
of the existing pitched roof.

In relation to point 'B' highlighted above - how much tolerance applies? For instance, if you're designing a single storey flat roof extension to the rear of a bungalow, and if you want to maintain ceiling line between existing and new, taking the necessary requirements for a parapet into consideration, you're probably going to have to go a small bit higher than the existing eaves; maybe 200-400mm higher depending on existing ceiling line and detailing of new etc.

Just wondering if this is a major deal? or do you have to strictly comply with the existing eaves line resulting in a lower ceiling in the extension? I would imagine it would be ok considering point 'C' above.

Gumbo · 21-02-2016 1:42pm

It's as strict as you want it to be. Who is signing off on the extension? They technically cannot sign off in it and if you ever need to sell a surveyor will ask for the planning grant or a copy of the certificate of exemption which cannot be provided as you have gone above the eaves.

Usually there's some tolorance for building methods but for somethings that's as clear cut as an eaves you need to remain below it in my opinion.

Alternatively, you could get planning for the extension.

bemak · 21-02-2016 3:54pm

ya planning would be the best option really

BryanF · 21-02-2016 10:20pm

bemak wrote: »

ya planning would be the best option really

Section 5 declaration

bemak · 22-02-2016 9:53am

BryanF wrote: »

Section 5 declaration

That had crossed my mind but would the planners just see that the flat roof exceeds the eaves and say that it then triggers planning.

Worth a go though. Thanks!

Gumbo · 22-02-2016 6:24pm

bemak wrote: »

That had crossed my mind but would the planners just see that the flat roof exceeds the eaves and say that it then triggers planning.

Worth a go though. Thanks!

Worth a go if you have the time.
Where is the house located?

bemak · 23-02-2016 9:49am

Carbury in Kildare. Out in the countryside.

Gumbo · 23-02-2016 10:59am

bemak wrote: »

Carbury in Kildare. Out in the countryside.

Sorry, if in Dublin i could have asked someone in the know close to the coal face

bemak · 23-02-2016 12:09pm

kceire wrote: »

Sorry, if in Dublin i could have asked someone in the know close to the coal face

ah thanks! I find it a bit odd that you'd need planning for the extra 200-300mm but if you made the roof pitched you'd be ok (as long as it's under the ridge).

I'll have a chat with KCC - I'll post up what they say

Gumbo · 24-02-2016 4:37pm

bemak wrote: »

ah thanks! I find it a bit odd that you'd need planning for the extra 200-300mm but if you made the roof pitched you'd be ok (as long as it's under the ridge).

I'll have a chat with KCC - I'll post up what they say

Wouldn't the pitched roof have to be under the eaves too?

bemak · 24-02-2016 5:10pm

No the pitched roof just has to be below the ridge. see point (c) in the original post. That guidance is from the CoCo.

As it's a bungalow, the eaves are only at +3m (approx).

Gumbo · 25-02-2016 2:13pm

bemak wrote: »

No the pitched roof just has to be below the ridge. see point (c) in the original post. That guidance is from the CoCo.

As it's a bungalow, the eaves are only at +3m (approx).

Don't forget that even with a pitched roof, the block work must stop below the existing eaves level. You can indeed continue the pitch of the roof and do not exceed the ridge height, but the gutters/eaves of the new extension must match or be below the existing eaves level.

bemak · 25-02-2016 2:16pm

I think that's why it makes more sense to have a pitched roof in this instance because linking in with existing eaves and fascia line is easier and allows the ceiling height inside to be maintained

lore83 · 21-02-2017 8:51pm

Hi, I realise this is an old thread, but was wondering what reply you got of the County Co regarding the flat roof height?
Am having a similar problem. Building a small rear extension to a bungalow (in an estate) & a neighbour behind us (not directly) is complaining. We were told before we started that everything was fine and the roof height would be grand. But now everyone seems to be not so sure. We have stopped works and put in for a section 5 declaration. Not feeling very hopeful

Gumbo · 21-02-2017 9:17pm

lore83 wrote: »

Hi, I realise this is an old thread, but was wondering what reply you got of the County Co regarding the flat roof height?
Am having a similar problem. Building a small rear extension to a bungalow (in an estate) & a neighbour behind us (not directly) is complaining. We were told before we started that everything was fine and the roof height would be grand. But now everyone seems to be not so sure. We have stopped works and put in for a section 5 declaration. Not feeling very hopeful

What height is your blockwork at? It cannot,exceed the eaves of the existing house.

lore83 · 21-02-2017 10:15pm

kceire wrote: »

What height is your blockwork at? It cannot,exceed the eaves of the existing house.

Hi, its my understanding that the wall can't exceed the height of the rear wall. Which actually goes a block higher than the eaves. As the eaves hang over it. The walls right now are just under the eaves. But the plan was to go up to the height of the rear wall (a block higher than the eaves) & have our roof under that, the wall height being the parapet.

Gumbo · 21-02-2017 10:16pm

lore83 wrote: »

Hi, its my understanding that the wall can't exceed the height of the rear wall. Which actually goes a block higher than the eaves. As the eaves hang over it. The walls right now are just under the eaves. But the plan was to go up to the height of the rear wall (a block higher than the eaves) & have our roof under that, the wall height being the parapet.

It's my understanding that eaves is the limit.
Who is signing off on the project?

lore83 · 21-02-2017 10:30pm

kceire wrote: »

It's my understanding that eaves is the limit.
Who is signing off on the project?

As it's below the 40sq metre rule. We didn't think we needed anyone to sign off on it. So we had a technician do the drawings (which she said we're fine) & hired a builder. It wasn't till our neighbours started complaining that it even crossed our minds that we might be outside exemption. We talked to our two neighbours beside us before we started and showed them our drawings of what we planned & they were fine. So now we have all the foundations and walls built & are worried that we'll have to change them. Which financially isn't really possible.

Gumbo · 22-02-2017 9:51am

lore83 wrote: »

As it's below the 40sq metre rule. We didn't think we needed anyone to sign off on it. So we had a technician do the drawings (which she said we're fine) & hired a builder. It wasn't till our neighbours started complaining that it even crossed our minds that we might be outside exemption. We talked to our two neighbours beside us before we started and showed them our drawings of what we planned & they were fine. So now we have all the foundations and walls built & are worried that we'll have to change them. Which financially isn't really possible.

Who signed off on the foundations, a Structural element?
What will happen in the future if you plan to sell?

What happens if it was to fall down tomorrow?

Planning Question: Flat roof extension & eaves

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