Pre-fab house extension kits?

[Dougal]

Hi,

My elderly relatives need a single-story extension (say 12-30 m2 tbd) to their small 2-storey semi. This would be for a new bathroom and extended lounge. Roughly speaking, all that is needed is a rectangular habitable box 'bolted' on to the back of the house, with access via existing patio doors (to be removed).

Maybe I've seen too many 'Grand Designs', but I was wondering if there are viable pre-fabricated kit alternatives to the usual messy and time-consuming traditional bricks, mortar , plaster concrete etc extensions. Something made up off-site for very quick assembly is what we'd want. Doesn't much matter what materials it is so lomg as it works, is cheapish and meets regs.Where can I get more information to pursue (or kill off!) this idea?

I know there will be sundry planning / building control issues to look at as well.

Cheers, Doog

[Andrew Mawson]

extended

habitable box

time-consuming

Something made

regs.Where

Well Portacabin style buildings in all sorts of configuarations are available and relatively cheap s/h

AWEM

[Owain]

Timber frame is what you need - bespoke, but manufacturered off-site (or pretty quick if stick-built on site).

Also google SIPs - structural insulated panels

Owain

[Dougal]

Something like a Portakabin but a bit more suitable to use as a house extension and will look OK in that setting (ie will not make back garden look like a building site).. Must meet building control & regs (fire, inulation etc) - hopefully modern timber frame might be OK in this regard?

Been looking on 'net, so far found a few kits for full houses, timber offices, garages etc but these seem intended, at least, for use as detached structures.

Maybe I need an architect!.

[Mick6]

rectangular habitable box

Wickes used to sell these in the '80s. I think I've still got the dubioulsy named "Good Ideas" leaflet for it somewhere. Looked bloody awful.

[Owain]

Yes, and can be brick clad or rendered etc.

Owain

[Anna]

rectangular habitable box

Try googling "garden office"

Anna

[Dougal]

So far I'm not sure if I've found what I'm looking for (ie ready assemble home extension kit with no bricklaying plastering and the like), at least within budget. But, will keep looking... - thanks for the pointers

Now as a concept I like garden offices but I'm not sure most are suitable to be abutted to a house?. Ecospace though have a very nice one to Building Stds, but the £20k price tag an issue.

Portacabins and shipping container-type-boxes may have their uses but not, I would think, abutted to a house as an extension (building regs?). BTW do portacabins come ready-assembled (a problem with restriced access) or as packs or sections?.

Timber frame / SIP construction might be a good option in the end, though cladding in brick or render gets away from the original idea of just assembly. Will try to find out more.

[meow2222]

Why not make your own kit, just construct wood frames from oak for each wall, and once the kit's made you can put the building up very quickly.

Dont be tempted to use whitewood for bathroom construction.

NT

[Owain]

They come in modules about 12' x 40' max, which can be craned into place (over the house if you have a big enough crane).

There are actually some smaller cabins (for gatehouses and the like) and shipping cabins that come as flatpacks.

You will always have some measure of assembly on site, because to get planning permission for an extension planners will usually want the finish to match the existing, and it has to be joined to the house somehow.

But once the foundation is poured, on-site time could easily be a week followed by final making good.

Owain