Advice on extension

[MonkeyHunter]

Hi,

Im looking to do an extension in the not to distant future (latest next summer), and am just trying to get my head around some of the details so I can get an idea of what is involved and how much it might cost me.

I plan to do most of the work myself, and don't want to involve a BCO, until I have a better grasp of what's involved, and when I might do this.

The house is a 1950's ex council mid terrace, and as it currently stands, the previous owners have 'extended' the kitchen by knocking through into what I guess used to be the outside pantry. This has been done to a very poor standard, with minimal insulation, and so that in heavy rain water finds its way in above the door frame....

My thinking is to extend to the same depth as the existing all the way across the back of the house.

My neighbors 'pantry' backs on to mine (their house is a mirror image), and the main thing I am wondering is if I would be able to utilise the existing party wall as part of the extension?

The main obstacle being that i would like to decrease the pitch of my roof, in order to increase the height of the extension at the back wall.

It is a single brick wall, so if it is ok to do this then would I:

1) Build the extra wall height as a single brick wall above the existing.

2) Just build a half brick wall on my side of the party wall...

If I do either of those, would I just trim the tiles on my neighbors roof to fit, and insert flashing?

Also given that this wall would be largely sheltered from the elements by my neighbors pantry, would it meet regs just to use thick insulated plasterboard on this wall or would I need to build another skin so the wall becomes a cavity wall? I realise that there would be nothing stopping my neighbor removing their pantry at a later date.

The rest of the extension would be reasonably straight forward I think, as I can build a cavity wall on the boundary with my other neighbor.

I know I would need party wall agreements for what i want to do.

Sorry for the verbose post, but I wanted to give as much information as possible. If anyone can shed some light that would be great!

 

[^woody^]

Ok, here is the woody consise guide to extension specification

1. It has to stay up - not sink, rock, or fall apart
2. It has to keep the inside drier than the outside
3. It has to keep heat in, and cold out.

The woody consise guide to party walls

If it belongs to you, you can build on it.
If it is shared you can build on it if you ask the neighbour.

There are other little details, but generally the above applies. What is the best or most appropriate or even possible option depends on lots of factors, which no-one can tell you from a forum post.

BTW, are you getting plans drawn or doing this under a building notice?

If you are making a notice, then don't expect the BCO to tell you how to build - he will expect you to tell him how you are building!

If you get plans drawn, then you don't have to worry at all- someone will tell you how to build it

 

[MonkeyHunter]

Thanks Woody.

I haven't decided which route I will go down with Building control yet, probably full plans, but I would probably try and do them myself. Now that might sound ridiculous after reading my previous post, but a neighbor a few doors down has done a similar extension and has kindly given me the plans. Regs' Wise it's all a little out of date, but I can base my plans off of them. I just didnt want to go drawing plans that use a party wall, only to find you cant do that sort of thing and have wasted my time.

TBH, it doesn't seem that difficult to build an extension, and I am confident I could cover off your 3 points, and have an extension that is much much better than the existing, which fails on points 2 & 3! (I imagine the only reason it passes point 1, is that it is part of the original structure of the house)

I guess if I draw up plans of how I want to do the extension, the BCO will soon let me know if he has any issues.

 

[^woody^]

Yes, but its not just a case of drawing plans, you need to know that what you design can actually be built too. There are lots of ways to build, but only a few wars to build economically.

Your only potential issue may be how to deal with building on the party wall, so you need to determine what is best to do here.

Building an extension is not difficult. But dealing with the inevitable issues which arise when things don't go according to plan is the hard bit. And a sure way to annoy the BCO is to continually ask him what to do

 

[MonkeyHunter]

Yes, but its not just a case of drawing plans, you need to know that what you design can actually be built too. There are lots of ways to build, but only a few wars to build economically.

That should be simple, as I will be doing the work, I wont design anything I cant build! Failing that I know a brickie that will help for a bit of cash in hand.

As far as i am concerned the basic structure ought to be reasonably cheap, if I utilise the party wall, then I just need a blockwork cavity wall for the opposite end of the extension I would render that wall to match that neighbors house, and a few bricks for the front of the extension.

Add sliding doors, window, joists and roof and its weather tight.

I need to bring the floor up, so was thinking block and beam, insulation and screed to do that.

Your only potential issue may be how to deal with building on the party wall, so you need to determine what is best to do here.

This is my main concern, I could build another wall parallel to overcome this issue, but then obviously my extension will start to shrink, which I would like to avoid. I think the Party wall agreements should be easy enough to get. I cant myself see any problems, structurally, to increasing the party wall height, trimming the tiles, and running flashing. But am happy to be corrected.

Building an extension is not difficult. But dealing with the inevitable issues which arise when things don't go according to plan is the hard bit. And a sure way to annoy the BCO is to continually ask him what to do

I have been doing some research so think I can cope with the drawings & anything that crops up.

The other problem would be rerouting the soil pipe, but the drains are clear of the end of the extension, and im sure I will come up with something if i have a cuppa and a think.

Maybe ill knock some quick plans up in sketchup.

 

[DoctorC]

even if you plan to avoid spending money on an architect or architectural technician, see if you can find one that will at least 'run an eye' over your proposals.

doing it yourself may save you their fee, but you can easily spend that on mistakes and 'i wish i'd known that at the time' issues.

If you have built before, fine, but building an extension is a whole lot more involved than re-decorating and internet research / reading.

£500 or £1000 to an Architect for a little advice WILL save you more than this in the long run - guaranteed.


PARTY WALL - you dont just need to tell your neighbour, you need their permission. They can say no. If you are in Englandshire, you will probably need a party wall agreement.
I hope you are friendly with them.


BCO will require you to prove your structure. Get a Structural Engineer to provide an SER certificate and you're laughing.

What sort of ground is it?
do you know what sort of founds you should have in that sort of ground?

etc etc

save the money by building it yourself.
save MORE money by paying for the advice.