Ways of Building Very Close to Another Wall?

blobert

Hello,

I'm looking to build a garden room/shed of about 10-15m2. It's going into an odd triangular shaped corner of the garden and will need to be triangular in shape itself. I want the structure to be well insulated so it can be used as a room to work in as opposed to just a timber shed. I'd also have a couple of windows/rood lights in it for daylight.

Ideally I'd like it to be as close to the boundary wall as possible (as if I had to leave a gap of say 80-100cm it would limit the potential size of the building) so what I'm wondering is if there is any construction technique that would allow to lets say have only a gap of 10cm from the shed wall to the boundary wall?

I was thinking of building using SIPs as they are relatively simple/quick to use and can have a good level of insulation. However as far as I'm aware you'd need to apply a breathable membrane and cladding/render afterwards which you'd not be able to do if you've only a 10cm gap to the boundary wall.

I'm thinking a cavity wall with brick on the outside would probably allow you to get closer to the wall but it would probably be slow to build and more expensive.

I'm looking for the front side of the shed to be clad in timber while the other 2 sides will be beside the wall/not visible so I don't care how they are finished.

If anyone has any ideas of how I could achieve what I'm looking to do (build very close to a wall ideally with a quick build system) I'd appreciate it!

Here's a rough idea of how I'd like it to look:



Thanks!

Roger Mellie Man on the Telly

Just use the existing wall as superstructure. Add whatever insulation/cladding you see fit and weather it at the top.

Gumbo

Roger Mellie Man on the Telly wrote: »

Just use the existing wall as superstructure. Add whatever insulation/cladding you see fit and weather it at the top.

Need agreement with the neighbors for this but I’d tend to agree.
Get an agreement and it becomes a party wall agreement.

If the boundary wall is sufficient, build it up to a parapet and put your flat roof on your side.

landcrzr

How useable will the space be when you're finished though? Two very acute angles in that shape.

blobert

Roger Mellie Man on the Telly wrote: »

Just use the existing wall as superstructure. Add whatever insulation/cladding you see fit and weather it at the top.

Thanks, we can't use the boundary wall unfortunately as the neighbours will object.

It's going to be a planning exempt structure as it's less than 25m2.

blobert

landcrzr wrote: »

How useable will the space be when you're finished though? Two very acute angles in that shape.

It's not an ideal shape but I'm planning to use the angled bits as storage.


If anyone had any ideas of ways you could build as close to the wall as possible that would be great.

I'd seen SIPs panels covered in steel on sale in the US which look like they might be suitable but I don't think they are a common product here?

Lumen

I don't really see the problem. Just build the deck, build a sheeted stud wall but rather than raising and cladding, clad it before raising.

Leave at least 50mm ventilation and drainage gap to the boundary wall. You'll probably need more than that anyway for roof overhang.

Could you not just build a wooden shed? Like a shiplap style one? Then insulate internally with insulated plasterboard or such? When my (8x12ft) shed was being delivered/assembled, each wall was already made up on the back of the truck, and they just stood them in place. Could be a potential issue in terms of getting access to it to maintain it, but if you can't see it, it doesn't really need to be pretty.

I've a "gym" which is insulated (shoddily/cheaply) with sheets of aeroboard behind plasterboard. My plan wasn't to make it a livable, usable space, but i got the aeroboard practically free, so i stuck it in and stuck plasterboard on it and skimmed/painted it. It's about 4 years old now and not a bother on it.

Just an idea.

blobert

Lumen wrote: »

Just build the deck, build a sheeted stud wall but rather than raising and cladding, clad it before raising.

Thanks, can you give me a little more detail on this, I don't really understand what you mean/how it would work.

I was also considering building with these:

https://www.clayblock.ie/product/porotherm-365-t7-mw-insulated/

They appear to be fairly weatherproof as is and I figure I could apply some further sealing (such as rubber paint/waterproof layer to the side of the bricks that would be beside the wall.

This way I could build very close to the wall and the one 365mm block will provide a good level of insulation (0.18w/m2K) with not that thick of a wall (which will help in terms of the total area of the shed/room)


Any further advice would be much appreciated.

Lumen

blobert wrote: »

Thanks, can you give me a little more detail on this, I don't really understand what you mean/how it would work.

Like this:

https://www.youtube.com/watch?v=qJ-b4A2IFPc&t=371s

I wouldn't necessarily recommend the rest of that video as a guide, but you can see that it's easy to frame, clad and raise a wall close to a boundary. There are loads of good Youtube videos from the US about framing and cladding walls.

The Poroton approach seems harder since it needs to be finished after building. I did consider them for my own build but was talked out of block building by my hugely supportive civil engineer uncle who said I'd be crap at it. :pac:

Fine Cheers

What is the height and condition of existing boundary walls ? I take it you will not be altering them at all. Can you expose the foundation to establish depth and width on your side. Is a composite roof panel an option for the 2 walls, assembled on the ground and then lifted into place. Prefinished so maintenance free which is important as you wont have access. Do it in sections so panels don't get too heavy. Provide a timber structural frame bearing on existing foundations or dig for new pads. For roof, avoid gutters at boundary and slope towards house. For that roof shape, epdm or fibreglass might be neatest and easiest to work with on a timber deck ? Maybe a raised parapet all round with hopper outlets at low points.

blobert

Lumen wrote: »

Like this:

https://www.youtube.com/watch?v=qJ-b4A2IFPc&t=371s

I wouldn't necessarily recommend the rest of that video as a guide, but you can see that it's easy to frame, clad and raise a wall close to a boundary. There are loads of good Youtube videos from the US about framing and cladding walls.

The Poroton approach seems harder since it needs to be finished after building. I did consider them for my own build but was talked out of block building by my hugely supportive civil engineer uncle who said I'd be crap at it. :pac:

Thanks very much for that, that makes it a lot clearer. I think that could work well and you could add in insulation.

Ideally I'd like to have somthing that's very well insulated as this room is also likely to be housing a lot of batteries for our solar system and I believe it's better for the batteries to be in an environment that's not freezing in winter.

blobert

Fine Cheers wrote: »

What is the height and condition of existing boundary walls ? I take it you will not be altering them at all. Can you expose the foundation to establish depth and width on your side. Is a composite roof panel an option for the 2 walls, assembled on the ground and then lifted into place. Prefinished so maintenance free which is important as you wont have access. Do it in sections so panels don't get too heavy. Provide a timber structural frame bearing on existing foundations or dig for new pads. For roof, avoid gutters at boundary and slope towards house. For that roof shape, epdm or fibreglass might be neatest and easiest to work with on a timber deck ? Maybe a raised parapet all round with hopper outlets at low points.

Thanks for that also, I really appreciate it.

Combining your and Lumens suggestions I wonder would somthing like this be a good option:

https://www.panelsell.ie/insulated-wall-panels

Looks like they might fit the bill in several ways. It looks like they are weathertight (if covered in steel) and like they slot into each other so I think it would be relatively easy to get close to the boundary wall.

They also seem to offer good U values with not very thick walls, the 120mm panel is 0.19 W/(m²K) which is pretty much as good as the 3 times thicker clay blocks.

PS the existing boundary wall is old, made of a mixture of granite and concrete in parts. It's about 2.2m tall with about another 80cm of ivy/plant growth on top so more like 3m. I'm intending to stay away from it.