First floor extension on stilts

[Newbyak]

Can anyone tell me if it is possible to build a rear extension on stilts? We need another bedroom but to build out on two floors would mean the ground floor going over drains and the start of a sewer pipe. It would also take away our turning circle meaning we could not pull a car onto the back of the house as at present.

I did think it may be possible to use piling to do the stilts and then connect up at first floor level. The house is 200 years old though and worried about piling so close to the house. So is this possible and might it be reasonable idea. If yes, any advice on how to go about this would be gratefully received. If no, any advice on alternatives would be gratefully received.

 

[^woody^]

Yes you can. Columns though , not stilts

No need for piling, as a pad foundation will often do. Or some sort of cantilever off the main house

Your biggest problem though will be getting this through planning, as planners are not known for appreciating anything out of the ordinary

Design wise, these would normally be of timber frame to make it light, and designed to contrast with the existing house and not match it. So, someone with a bit of flare for design may be better than a normal plan-drawer technician

 

[Newbyak]

Many thanks. Problem I have with that is that I live in a conservation area. We are on a corner with a road to the side and front. The extension would be visible from the road and would have to be in stone to match the area. Contrast will not be allowed. Would columns support this? Also, if I use a concrete pad I would need to have holes for the manhole and drain covers. Would this weaken the pad and make it less likely to be appropriate?

 

[^woody^]

Conservation areas do not require matching of design. The crucial issue is how the design fits in, which is a different concept. That is why a good design(er) is required, not just someone who draws extension plans

Pads need not affect drains unless the drain is directly under the pad - which will be the same problem if using piled foundations

Alternatively, you can build in stone, its just that loadings and structural supports will be a lot more costly to design and build

 

[Newbyak]

Thanks Woody. I did not know that about conservation areas. I'll look around for someone to do the design. Perhaps my next questions will be about how to find a suitable designer.

 

[^woody^]

This might be one of those rare occasions when a proper Architect (RIBA) may be the best choice - as they will tend to that the flare and intuition to design something suitable. Architects will charge a lot more than run of the mill technicians, but it may be the only way to get a suitable design

But you really need to get some people around to give you some specific advice, and judge for yourself what they can offer

There will also be structural engineers fees, which again may be expensive

But in context, to get something designed to suit you and acceptable to planners, then it may be an expensive thing in any case

If you did go ahead, I'd be interested to see what design someone comes up with and what is eventually built

 

[Newbyak]

yes, you are right. We will give it some thought and update the post.

 

[^woody^]

This might be useful - free Architect consultation for a donation to Shelter

www.architectinthehouse.org.uk/?appeal=1051300

 

[Newbyak]

Thanks again woody. Will certainly do this.

 

[freddiemercurystwin]

Probably cheaper to divert the drains.

 

[Newbyak]

yes, but I cannot figure out a way to do that. It is the start of a sewer pipe that has outlet to two Bathrooms into it. If I move it I have to raise it to get the fall. That then creates further problems. I think the drains really have to stay put.

 

[^woody^]

If you just needed to move drains, then that would normally be possible.

So if this is the only criteria, and not the turning circle issue, then that should be looked at.

But the costs of building, knocking through and fitting out a ground floor extension and moving drains, may be more than building a first-floor extension on columns

You should concentrate on what you want, and let your designer tell you what you can have, and at what cost

 

[Newbyak]

Thanks for this. I am overwhelmed by how generous people are with their time. I did not really expect any answers so this has been fantastic.

Obviously I am not being clear:

The turning circle is most definitely an issue so we have to build on columns to retain the drive area.

The drains are a further complication. They need to be taken into account when planning the pillars or columns. Trust me, they cannot be moved! Ours is a bermed house and the sewer is already higher than the first floor. Very difficult to raise further but if we move the sewer we have to raise it to retain the fall we need to allow the sewer to drain. We have some wriggle room in moving connecting drains , but very little and for the same reason.

I will go to an architect as soon as I can. (waiting for some overdue fees to be paid to me and then I can move progress). This is a real tricky one but now that I know that building on columns is possible I think we will give it a go.

Many thanks for the trouble taken and for the interesting and informative suggestions.

 

[MULLY]

Hi Newbyak,

Just wondering how you got on with this? we are in exactly the same situation, need the car space around the house and want to put a first floor extension with possible attic room on top again, all on columns. It also avoids going near sewage pipes gas lines etc etc.

Cheers,
N

 

[Newbyak]

Hi Mully

Few issues at this end meant we tried to sell and move. But that has proved a little difficult in the recession..

Here is what we looked at:

Away from the house we could build an underground room. We have a friend who designs these things in places like London where property prices warrant it. He told us it would be more expensive than building a single story flying extension, though the flying extension would be more difficult to heat.

At the moment my partner is living and working abroad, so I dont think this is going to happen. More likely the kids and I will move house.

I will post again if things change.