Can I build an extension?

jimmycrackcorm

Hi

I'm thinking of building an extension to the back of my house. However there are two manholes in the back garden close to where I would like to build. This means that there are obviously waste or whatever pipes running through the garden for the estate. Does that mean I would be unable to lay a foundation for an extension?

J.

smashey

Hi jimmy,

They can be moved. Go ahead with your extension.

jimmycrackcorm

Ta Smashey.

Some more questions that I find confusing from reading the planning exemption guidelines: It says that you can build an extension up to 40sq metres without permission but if it is above groundlevel it is restricted to 12 sq. metres? Does this mean that If I build a two storey extension at the rear that the floor area is restricted to 12 sq metres on the first floor and 28 sq metres on the ground floor?

Also if I build the extension actic with a view to future conversion to living space, does this class as additional living space?

J.

smashey

Oh no. You mentioned attic conversions. :eek: We had a big debate about attics here.:D

jimmy, are you in a semi-detached?

muffler

jimmycrackcorm wrote: »

I'm thinking of building an extension to the back of my house. However there are two manholes in the back garden close to where I would like to build. This means that there are obviously waste or whatever pipes running through the garden for the estate. Does that mean I would be unable to lay a foundation for an extension?

As smashey said they can be moved but you may need to check that they are servicing your own house only. If they are servicing other houses and running through your garden you would also need to establish if there is a wayleave in place. In that situation you may have to leave the pipes and case them in concrete plus provide manholes either side of the extension.

jimmycrackcorm wrote: »

It says that you can build an extension up to 40sq metres without permission but if it is above groundlevel it is restricted to 12 sq. metres? Does this mean that If I build a two storey extension at the rear that the floor area is restricted to 12 sq metres on the first floor and 28 sq metres on the ground floor?

That is correct if you live in a semi detched or terraced house. If its fully detached you can build 20 sq. metres on each floor subject to to certain pre-conditions.

jimmycrackcorm wrote: »

Also if I build the extension actic with a view to future conversion to living space, does this class as additional living space?

Again as smashey said there is a separate thread about it. You also need to watch out for one of the pre-conditions which states that the height of the extension roof cannot exceed the height of the roof of the existing house.

jimmycrackcorm

Yep, semi-D at the start of the estate.

I was also considering a single storey to the rear with a large enough /\ roof on top that could be used as a playroom with velux windows?
I don't mean converting the existing attic as it is too small ( slanted all 3 sides )

muffler

jimmycrackcorm wrote: »

Yep, semi-D at the start of the estate.

I was also considerig a single storey to the rear with a large enough /\ roof on top that could be used as a playroom with velux windows?

You probably wont get that without having to apply for PP

jimmycrackcorm

muffler wrote: »

You probably wont get that without having to apply for PP

So you can build a two story extension with a non-attic roof without PP but a single story with a roof and windows require PP?

muffler

Apologies j.

I misread that part of the post - I thought you were referring to a 2 storey extension with a high "A" type roof.

jimmycrackcorm

muffler wrote: »

Apologies j.

I misread that part of the post - I thought you were referring to a 2 storey extension with a high "A" type roof.

I think it might make more sense to build a single storey with a pitched roof that would allow the space to be used as a single bedroom perhaps. Also I presume that means by panelling in the sides, the first floor space is reduced to the 12 sqm requriement.

muffler

jimmycrackcorm wrote: »

I think it might make more sense to build a single storey with a pitched roof that would allow the space to be used as a single bedroom perhaps. Also I presume that means by panelling in the sides, the first floor space is reduced to the 12 sqm requriement.

The 12 sq. metres normally applies to a full 2 storey extension. However if your roof is so designed as to incorporate a bedroom then the actual area of floor space in the "attic" cant exceed the 12 m2 limit. This may not always be achievable depending on the width of the ground floor/roof span.

You need to also keep in mind things like ceiling heights, any windows on first floor/attic to be 11 metres from boundaries, 25 m2 of open space retained in rear yard, fire regulations etc etc

jimmycrackcorm

muffler wrote: »

You need to also keep in mind things like ceiling heights, any windows on first floor/attic to be 11 metres from boundaries,

Surely that can't be right. I doubt my back garden is not much wider than 11 metres?

jimmycrackcorm

Sorry, back to the original question. The manholes would be beside the extension but I was wondering if the pipes underneath affect or prevent a foundation being laid?

sydthebeat

jimmycrackcorm wrote: »

Sorry, back to the original question. The manholes would be beside the extension but I was wondering if the pipes underneath affect or prevent a foundation being laid?

no.. there are procedures the builder can take to 'bridge over' existing pipes when digging foundations.....

regarding the first floor window issue, muffler is saying that if a first floor window occurs within 11 m of the boundary it faces, then the development is not considered 'exempt'

Mellor

Which means in your situation, the /\ roof can have no side windows facing the gardens beside. All the same conditions will apply, make sure you check them all before to start to build.

250882

Just think of the estate where you are living. I can guarantee you that there are no windows in the sides ofthe houses and if they are they are frosted.

muffler

sydthebeat wrote: »

regarding the first floor window issue, muffler is saying that if a first floor window occurs within 11 m of the boundary it faces, then the development is not considered 'exempt'

Yeah, thats what I meant - I should have been a bit clearer though about the "facing" boundary.

jimmycrackcorm

That's fine because I think Velux windows would be the better option. I was also wondering if it was possible / cheaper / better to do a timber frame extension?

Just think of the estate where you are living. I can guarantee you that there are no windows in the sides ofthe houses and if they are they are frosted.

Does that imply that it's possible to put in a side window that is frosted given that the landing frosted window is on the same gable side?

I've attached a jpg of what I'm thinking of doing. It's a side view and the area in red is the extension. Is this doable?

Note that the original houses in the estate have a "Sun room" extension already which I believe doesn't count as an existing extension as the houses were all built originally with it. Rather than mess with it as the neighbours house has the same and it would affect their area, I wanted to build the extension seperate. Is it permissable to have a velux window at (1) facing the existing building given that the neighbours rear bedroom window is very close by.

Mellor

Afraid not, the houses recieve planning permission I imagine. You are looking at exemption.
It is possible to apply for planning and get the go ahead, but it is unlikely.
If you want to go the exemption route, you can't have a window there.

jimmycrackcorm

Another issue that I find confusing is what is classified as a second floor. In my design, I have a high pitched roof for example that could for example be ceilingless. But if I have put an open mezanine covering half of the area then is that classified as a second floor?

Mellor

You mean first floor. The second story is first floor.

What is confusing exactly.
First floor is simply the floor above ground floor.
You could have a high sloped ceiling. You would fit a floor in here, Unless it was double height, then this would be a first floor.
By the way, trying to say is is a mezzanine is a cope out, a mezzanine is not simply a half open floor sharing a ceiling, it is a small floor between two main floors. It is not counted in the total floor numbers. What you described would not be a mezzanine, to be a proper floor it would need something close to a proper ceiling height, a stairs etc, and in most houses it would be a first floor and not a mez, they are some exceptions.

jimmycrackcorm

Ok. for an exempted first floor, it mut be built a minimum of two metres from the boundary with the semi-detached neighbour. If s I said I have a high pitched roof that is open then that is classed as a single ground floor with a high roof ( not above the existing roof level) and so can be built within the 2 metres. However if I can fit in an upper floor area in the roof space but occupies the half that is further away from the neighbours side then does that count as still being exempt? i.e. the gable is within the 2 metres but the actual upper floor area is further away?

Mellor

Tht would still be class as two story and would need all the boxes ticked to be exempt. The half floor being two metres away but the gable not is a tricky one. The external impact isn't changed by moving the floor back, but the floor ara and such are complied with. If i wanted to go that route, i'd get a certificate of exemption for the LA. As even if you were later proved right, it wouldn't be worth the fuss.

muffler

jimmycrackcorm wrote: »

Ok. for an exempted first floor, it mut be built a minimum of two metres from the boundary with the semi-detached neighbour. If s I said I have a high pitched roof that is open then that is classed as a single ground floor with a high roof ( not above the existing roof level) and so can be built within the 2 metres. However if I can fit in an upper floor area in the roof space but occupies the half that is further away from the neighbours side then does that count as still being exempt? i.e. the gable is within the 2 metres but the actual upper floor area is further away?

jimmy you are splitting hairs here but thankfully in this instance the hairs are "well conditioned"

If you put down as little as 1 single sq mm of flooring anywhere in the "attic" area it becomes an upper floor by default and therefore the building must be 2 metres from the neighboring boundary.

You seem to be going to great extremes to avoid planning permission. Why not do what Mellor suggested and fire in an application for a certificate of exemption from the PA but they will only give that cert providing it is exempt.

Or why not just make a planning application to extend your house in the normal manner and that way you will have everything in order and wont have any issues in the future should you decide to sell or even re mortgage.

Mellor

Sometimes people tend to confuse the exemption limits, as the allowable limits when it comes to planning, which is not the case at all. If it was me, i'd go full PP regardless.
I actuall like the half floor idea, and in the right setting it would look very good imo