New 2017 Summer House project

[Joff-Turbo-Nova]

Hi all

I have been asked by SWMBO to make her a Summer House for 2017 when she is 50.

At first the initial requirements were quite modest, however since we visited Chelsea Flower show earlier in the year, her requirements list has grown .

Initially I was thinking of a 2m x 3m structure, however she's pushing for 4m x 4m as she wants to use it as an outside office - complete with bifold doors, 2 x velux windows, leaded feature side windows and a woodburner in the corner.

I am pretty OK in the DIY department, however metal is my preferred DIY material, more of the garage tinkering than playing a builder in the garden. However a few years ago I did build a 5m x 4m decking with 4" x 4" posts as the anchor points.

My question comes to the main floor frame and how to keep this off the damp ground. I was considering using 4" x 4" for the frame, but supported off the ground using something like these :-

I would mount these into concrete at regular intervals to ensure that there is sufficient load bearing capability. I was only going to raise it up an inch or so just to get it off the damp floor.

I was considering a concrete base but at 4m x 4m it would require tonnes of soil to be removed !!

Any help or suggestions most appreciated !

Jonathan

 

[John D v2.0]

You can just last a dpc on top of the concrete/brick base and then bed a timber plate on top of that. Never seen one of those brackets before, but I've no doubt they'd be suitable if you really want it.

 

[big-all]

just keep in mind you are restricted to a maximum 2.5m in height within 2m off the boundary to avoid the need to get panning permission
and although you get exactly what you want and usually better quality building building your own shed can work out about 25 to 40% more expensive before you buy any tools for its construction

 

[John D v2.0]

Agreed, manufactured off site is always going to be cheaper, but you have to treat it as a hobby rather then money saving if you wasn't to build something bespoke. If you do work on the house itself, it's much cheaper than builders because you needn't pay labour charges.

 

[Brigade77]

Are you looking to build it on a swamp?

I'm wondering how the ground is going to get "damp" when there's this great big shed on top of it?

 

[Joff-Turbo-Nova]

Thanks for all the replies, we live in a very heavy clay soil are and the water sometimes puddles in heavy rain. Short term I can build it on anything, but ideally I would only want to build this once in my lifetime, so looking for something that is going to last 15 years +

Agreed that this will be more of a hobby project than a cost effective offsite pre-made version - making it myself I can add in the features I want and where I want them . I was going to space these U posts at regular intervals to ensure the load bearing capacity is sufficient. I usually over engineer things so will probably end up putting in more than I really need !!!

Aware of the 2.5m max height to get in under permitted development building regs.

Cheers!

 

[motorbiking]

You are also restricted to 15m2 which you will be over if its 4m x 4m (unless your walls are a decent thickness) - otherwise it has to built out of substantially non-combustable material
https://www.planningportal.co.uk/info/200130/common_projects/43/outbuildings/2

I built something similar a while ago..

I dug my concrete base, - did it over a couple of weekend, mixed it with a cement mixer I already had and included insulation and dpc about 4-5m2 of concrete used. I then made a wooden frame and used ply, celotex and plaster board home made sips.
total cost about 4k - would have been 2k without such heavy duty insulation - its worth it though as we can use it all year round and heat it with a small fan heater.