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Help designing large shed for living! Answered


I am currently designing a large shed. I Have got the main look and all the lengths planned out, but I would be greatful l if someone was able to give my guidance of the constructiont, ei. Wood needed, The structuring of this wood and techniques etc. Electrics have already been planned out.
I will be using insulation in the walls and floors. The walls will be plaster board, The building will need to be pretty structuraly sound so this is why I thought i would ask! This is all I have planned on construction so far.
All feedback and/or critism is welcome!

I have attached a sketchup file for better viewing aswell as a few photos! The sketchup file has the exact measurements. For the whole building it is 620cm x 350cm

Edit: Sketchup upload has not worked so will give a link to it, I will also give out patches to anyone with very good advice!

Sketchup link: http://sketchup.google.com/3dwarehouse/details?mid=df6f6cc57f109a415cde8f73f76c923&prevstart=0

Many Thanks



If you current plans are centered around the inside dimensions of the building you will need to account for how much space the framing, wall cladding and dry wall will add to it.

If you are in the US you will want to frame it with 2x4s not 2x2s. Electrical boxes are typically just over 3" deep. Now if you don't plan to have any inside wall cladding then 2x2s will be fine and the boxes will stick out a bit.

Now a 2x4 is actually 1.5" x 3.5". Taking into account your 1/2" shiplap or plywood and then another 1/2" to 3/4" you will need for the inside wall covering (if any) and your looking at adding 4.5" to 4.75" to all sides of the building. Or subtracting that from the available inside space.

You can use either OSB or ply on the roof and outside. It really doesn't matter as long as you use at least 1/2 ply. I assume you'll be putting some sort of roofing over it anyway right? BTW your floor and the loft should be done with tong and grove 5/8" ply. The support beams for the floor and loft should be done with 2x6s at least. Since both inside walls will be load bearing walls you will need to put in good headers over the door ways. You may have to put in a good sized 4x4 beam over the opening into the larger room. Both load bearing inner walls should have your concreted 4x4 supports under them. At least at the outer ends of the wall. So you will want 4 support beams across each long side of the building.

Not knowing your actual dimensions (unless you've published this in the Sketchup 3D warehouse) and going off the bed as a twin sized bed reference the building is larger then most sheds. This could be considered a detached garage or small out building of some sort. Falling under all the regulations and building codes. So as others have said do your research on your local ordinances. They may dictate stricter or looser standards then what i've outlined above.

I understand this is a "large shed", but you've clearly mentioned "living" in this, and by your sketches, I see a number of things that are serious problems.

Framing. - Your design sketches do not take into consideration any framing. You've designed the walls, sleeping area and roof with no depth (as everything is sketched paper thin). Standard framing is made with 2 x 4's set at 16 inches on center and then you'll add your drywall (or plasterboard). (The rules may vary some in the UK, but I doubt by much in respect to North American building code). You'll want insulation in your walls and all your electrical and any possible plumbing needs to be accounted for in your plans. Otherwise if you begin with your outer framing dimensions (based on your sketch) and add your inner walls, I think you'll find that you have VERY LITTLE room left on the inside.

Ceiling Heights. - Based on your sketch, the lowest point of your roof slopes are barely a few inches higher than the door. Standard door heights are 6 feet 8 inches high. The ceiling height you should have on the inside is 8 feet or more. Remember that your ceiling needs framing too and is done with much larger beams than your walls because it must carry the load of the entire roof and be able to hold the weight of snow (if you live in an area that sees snow).

Sleeping Area. - Have you thought about how you intend to get up to this sleeping area? Do you plan to use stairs or will you use a ladder to get up there? (Based on your plans you have NO room for a set of stairs). The other big problem from your sketches, is again, your ceiling height in the sleeping area. If I use your door as a reference, I see less than 3 feet of room available to frame the floor for your sleeping area and to frame the roof that goes above. Even if you intend to use a ladder and simply crawl into this area, based on your sketches I doubt you'll have enough room to even roll over in bed, and there will certainly be NO room to sit on the bed.

I don't mean to sound harsh with my criticism, but there's no point in me (or anyone) giving you poor advice that will be a waste of your time and money. There's a reason why building plans (that meet code) are made by experts because they will take into account all the things you've clearly missed. These standards are also there for your SAFETY and I don't advise you to lie to the permit office and simply say its a shed if you intend to live in it for any length of time. A poorly constructed building can result in serious injuries (if not death).

I would be more than happy to offer you additional advice but I think you need to utilize some existing plans and get the help of professionals for all aspects of this build.

Thank you for your feedback,
Yes the sketchup file was mostly just to get the design and the dimensions of where the supporting posts etc. will go. The walls will not be that large, being 5' at the widest, I have made the rooms wider than they need to be in most rooms for this. I Will start planning the wood used.

I can see you point for ceiling height however it seems best if I keep it under 4 meters heigh as this made exceed nuilding permits.

There is a ladder drawn in the model however it cannot be seen! There is 1 meter on the left side and 1.5 meters on the right side, room to sit up in bed. The beams will go over this hiegh for the roof.

Yes, I will be getting a builder who has done something like this before to review the plans.
I'll keep you updated on the process



UK planning portal says it all here



Outbuildings are considered to be permitted development, not needing planning permission, subject to the following limits and conditions:

No outbuilding on land forward of a wall forming the principal elevation.
Outbuildings and garages to be single storey with maximum eaves height of 2.5 metres and maximum overall height of four metres with a dual pitched roof or three metres for any other roof.
Maximum height of 2.5 metres in the case of a building, enclosure or container within two metres of a boundary of the curtilage of the dwellinghouse.
No verandas, balconies or raised platforms.
No more than half the area of land around the "original house"* would be covered by additions or other buildings.
On designated land* buildings, enclosures, containers and pools at the side of properties will require planning permission.
Within the curtilage of listed buildings any outbuilding will require planning permission."

HOWEVER You do need to comply with Building regulations (building code)

This will affect your plans
"..Building Regulations

If you want to put up small detached buildings such as a garden shed or summerhouse in your garden, building regulations will not normally apply if the floor area of the building is less than 15 square metres and contains NO sleeping accommodation.

If the floor area of the building is between 15 square metres and 30 square metres, you will not normally be required to apply for building regulations approval providing that the building contains NO sleeping accommodation and is either at least one metre from any boundary or it is constructed of substantially non-combustible materials...."

More on the web page I linked earlier

Plywood is Much stronger then the same thickness chipboard. If you roof with chipboard you would need a substantial roof structure to support the chipboard to prevent sagging over time.

Have you checked with your neighbours - you may find they object to a substantial structure. this may well be a considerable hurdle.

You MUST find out before you start if there are any permits required.  The penalties for not doing that can be severe and expensive.

Even if no permits are required, since this is a residence then there are still standards you must follow.  Otherwise you may be building something very unsafe without even knowing it.

Most large lumber suppliers usually have an estimating department that is capable of supplying the proper sized materials for this project. 2 x 2s are not adequate for this structure.

You do need a foundation.

You should hire a professional electrician.  Wiring a whole house is not a beginner project.

In the UK you may find a LARGE shed WILL come under the planning regulations. However you may also find that the planning dept won't be too worried.

i would ring and ask just to be sure - It's a shame to have to knock it down.

Putting a "bed room" in it changes it's use and purpose. Call it storage space.

You WILL need some kind of platform to put it on - Paving slabs or concrete. Be aware that wind has a considerable effect on large buildings so attach to the ground pad.

Your electrics WILL need to be installed by a certified electrician and supplied with an armoured cable.

As for construction 2 x 2 framing 18 inches apart clad on the outside with shiplap at least 1/2 inch thick.

Roof 18 mm plywood with roofing felt over that the joists will need to be at least 4 x 2 and better 6 x2 to carry the roof weight.

Buy your materials from a wood merchant or it will cost you the earth.

Our allotment shed 10 feet x 20 feet cost us £1000 to have built so perhaps £500 to £750 in materials.

Thank you very much for your comment!

Yeah, I will double check with the regulations.
I was thinking having many 4'' x 4'' Vertical beams suspending the floor concereted into the ground?
I am getting a qualified electrictian to do it so that is all sorted.
That sounds good! Is there any difference in using chipboard for the roofing instead of plywood?
Thank you very much for your feedback!


5 years ago

I would double check the thing about permits. Here in the US you need a permit to build a garage depending on where you live.
I also noticed that something that is missing in your plan is a foundation. You can't just sit something on bare ground.

First off you'll probably need permits to build this and that means you will need to follow the local building code because it will need to be inspected. The building code will tell you how and with what to build it.

This Building won't be permanently lived in and it is still classified as a shed, so we are fairly sure it doesn't need planning permission here in the UK.