Timber frame annexe

[Invader75]

Hi,

 

I'm looking to build a timber frame annexe on a plot in our rear garden. I don't mind using pre fab companies as long as the look is right. 

It would be single story open plan one bedroom with wet room approx 8.5 x 4m. Has anyone got approx prices that something like this might cost? 

 

Just to get a general feel of whether it's worth paying a local architect and builder to create it or buy "off the peg" as it were. 

 

Many thanks 

[Jeremy Harris]

My guess is that with that small an area, the fixed costs of using an architect might well push the price per m² up by a fair bit.  Extensions are generally more exppensive than new builds, in terms of cost per m², for a host of reasons, and small extensions are disproportionately more expensive, again because of the fixed costs of things like building control, planning and mobilisation of stuff to the site

 

The cost per m² also varies a lot with region, with some areas perhaps as much as 50% more than others, due largely to wide variations in labour rates.

 

If it's a simple extension, with no complex design aspects, you could consider doing the design yourself to save cost.  You may or may not need a structural engineers input, it depends on what you're planning.  You may well find that an architectural technician would be better and more cost effective than an architect, as they tend to do a lot more smaller jobs like this.

[Brickie]

Do a bit of surveying on the building you're proposing to extend first. Are the walls plumb (vertical)? Are adjacent sides square to each other(90 degrees)?

these are just a couple of issues which might need addressing if trying to attach a timber frame kit to an imperfect,older building,and why,sometimes it's easier just to build something like this in ctraditional brick & block (or block & block.)

Those potential problems are not insurmountable,but they do need to be planned out,adding time & money. 

[Invader75]

It's not going to be an extension, it'll be a free standing dwelling. I've been looking at these guys for example. https://www.zedbox.co.uk

[Jeremy Harris]

If it's free standing, then that removes a fair bit of hassle, as you can treat it pretty much like a small self-build.  In that case, I think a timber frame package of some sort may well be a good option.  You get a quick build, that can be watertight in less than a week with many systems, and that alone takes a fair bit of risk out of the costings, as it minimises delays to the later work.

[Invader75]

Apologies if it's already been covered on one of the sections in here but are there any recommended companies or self builders doing a similar small annexe?