Garden office self build - crazy idea?

TheCyclingProgrammer

I've posted on here before about getting a garden office built in our garden later this year.

This is what I had in mind:
http://www.greenretreats.co.uk/garden-rooms/inspiration-garden-rooms.html?id=3x3

Fully specced up it comes to about £14k total.

I've had one quote from a local building firm and they've quoted me £28k + VAT to build something similar. Unfortunately I didn't hear back from any others.

In the name of money saving, I'm currently contemplating the idea of the self-build approach. I'm quite handy when it comes to DIY, I understand how these things are built and am confident I could do it - not on my own, I would need some help, but I'm wondering how viable this is?

I have a rough idea of what the material costs are and I intend to properly price it up. I'm estimating in the region of £6-7k with the biggest costs being the doors/glazing and possibly the cladding depending on what I clad it with (red cedar being the most expensive option). I would still need an electrician to do the internal wiring (though I could run a lot of the cable myself), hook up the power to the house and test and sign it all off. I'd also need a plasterer to skim the walls and ceiling.

I'm wondering if a good option might be to find a good local chippie who is happy to do some day rate work and help me with the initial construction of the frame.

All in all I"m hoping I can save maybe £4-5k doing it this way. Does this seem realistic? These buildings aren't complicated - solid base, insulated timber frame with sheathing, breather membrane and batten + cladding on the outside, vapour barrier and plasterboard on the inside, plastered and decorated finish and laminate + skirting. Are there any potential pitfalls? Has anyone else taken on a small self-build project like this before? Any advice?

Doozergirl

If one were ever to take on a first self-build project, I think that would be perfect.

I want picture updates

martinsurrey

Doozergirl wrote: »

If one were ever to take on a first self-build project, I think that would be perfect.

I want picture updates

Agreed, perfect intro to self build.

I've seem some amazing "sheds"

frame is important (and heavy and a 2 person job if you dont want to risk it), but so is your base, if you mess your slab up it'll cause you no end of pain down the road.

TheCyclingProgrammer

Yes, in terms of base I think I have two realistic options: a concrete slab or something like this:

https://swiftfoundations.co.uk/swift_plinth/

This seems a bit more foolproof. A concrete slab needs to be perfect and although I could get somebody in to do the slab, in the spirit of self build the above seems a bit more DIY friendly.

I'm guessing depending on how solid and level the ground is, I might want to lay down some compacted hardcore after excavating the area where the base will be situated?

I'm planning well in advance here, this will be done in conjunction with a garden redesign after Summer but if I go this route I'll be sure to post photos.

TheCyclingProgrammer

martinsurrey wrote: »

frame is important (and heavy and a 2 person job if you dont want to risk it), but so is your base, if you mess your slab up it'll cause you no end of pain down the road.

Yes, the plan would be to construct each wall separately and then fix them altogether. Would you fix the ply/OSB sheathing to each wall first before fixing them together or would that just make it too heavy to move around?

I'm guessing I'll want to hire some kind of nail gun to make my life easier too?

27cool

In my earlier years I would not have hesitated to do something along these lines.
I did once put up a conservatory which used a metal frame base. Very easy and still there with no problems, more than 14 years later.
I have built several large sheds over the years. Obviously a garden office would require a better finish, both inside and out.
One of the sheds (15ft x8ft) was up against a fence, so I had to clad the long back wall before installation. Very heavy, but we managed with two of us. A third person would have made it a bit easier.

System

A nail gun is more convenient for timber frame but you can never be sure they are driven home correctly, nailing by hand let's you know the nails are properly driven (have had many a "discussion" with joiners about hand driven nails...)
Build the panels with the sheathing on otherwise they will twist out of shape when you are moving them around, build them on the base so you are only lifting them up into position

TheCyclingProgrammer

the_r_sole wrote: »

Build the panels with the sheathing on otherwise they will twist out of shape when you are moving them around, build them on the base so you are only lifting them up into position

Good tip, thanks.

Igol

I built my 8x4m garage from scratch a few years back and its as dry and toastie (thanks to the gas bottle woodburner in there) as the day I finished.
My method was to construct 2x2m frames and the A frames for the roof which then just bolted together and pretty much made it a one man job.
Everything was treated with wood preserver before construction, to protect those bits that wouldn't be seeing the light of day again and then the whole of the outside was wrapped in DPM to weatherproof it a bit more. Double glazed upvc windows installed (ex-display off ebay for £20 each) then shiplap cladding on the outside to finish it.
Rockwool on the inside (leftover from another job) sandwiched in place with OSB with a thicker roofing grade for the roof which is felted with vapour barrier and 2 offset layers of felt. Silver bubble wrap insulation between the A frames completes the insulation and its a proper man cave.
Yes the frames flex when your putting them in place but that was an advantage to help get it square once on the footings.
A mates Dad was very impressed by the construction method and copied it to build his own shed.