Small Workshop Build - 4.8m x 2.4m

[Brdy]

Finally, after a couple of years of trying, I have a small amount of free time to build a workshop and hopefully fill it with tools!

Interested to share my design and progress over the next couple of weeks with everyone and it’s always good to get other peoples views and if there are easier ways to achieve the final product.

I will share a price list of everything as I go along.

The plan:-

Weekends 1 & 2 were digging out existing patio and grass area, the timbers in and type 1 stone compacted.

Weekend 3 is the concrete.

Weekend 4 & 5 hopefully the weather holds off and I can get the structure up, roof on and outside cladded.

Then a couple of weekends after that for other bits and pieces.

It’s a 4.8 x 2.4 pent roof workshop and will have a warm roof and insulated walls.

Current costs:-
Excavation & rubbish removal £0
Timber shuttering £60
Type 1 stone (free from work) £0
= £60

Timber for frame + shiplap siding (Excludes sheet materials)
Treated C16/24 47x75mm 2.4m x 37
Treated C16/24 47x75mm 3m x 13
Treated C16/24 47x75mm 4.8 x 6
19x125mm shiplap 4.8m x 50
= £764

 

[Molynoox]

When you say warm roof is it an actual 'warm roof' or just an insulated roof?

Assuming you are not going through planning and hence have the 2.5m height restriction, I would be interested in seeing how you will achieve a warm roof design and still have headroom inside.

Martin

 

[Brdy]

When you say warm roof is it an actual 'warm roof' or just an insulated roof?

Assuming you are not going through planning and hence have the 2.5m height restriction, I would be interested in seeing how you will achieve a warm roof design and still have headroom inside.

Martin

This is one thing that has had me thinking of lots of different designs! Fortunately I am a short guy lol so can get away with it being more of a shed than a workshop.

My plan is to go 2060mm from concrete base to top of walls, then use joist hangers to sit the roof joists flush with the top of the walls, then 18mm ply or Osb sandwiching 75mm celotex with good quality shed felt on top of that.

My garden slopes off too so need to account for that in my design to keep under 2.5m as you said.

My calculations add up to be 2171mm which leaves me over 300mm for the slope which would be the lowest point of ground surrounding the structure. I’m assuming this is where the 2.5m would be taken from?

EDIT: I have just had another look into the height restrictions and came across a handy article that states the measurement is taken from the heighest part of the ground immediately adjacent to the front of the building. This is very interesting as I thought it was measured from the lowest part of my whole garden.

This gives me a lot more wiggle room.

 

[Molynoox]

So is it a warm roof design or not?

 

[Brdy]

So is it a warm roof design or not?

From my reasearch a warm roof is insulation sandwiched between osb. So I would say yes.

 

[Molynoox]

From my reasearch a warm roof is insulation sandwiched between osb. So I would say yes.

Oh I think I understand what you are doing now

 

[Pallet Fancier]

EDIT: I have just had another look into the height restrictions and came across a handy article that states the measurement is taken from the heighest part of the ground immediately adjacent to the front of the building. This is very interesting as I thought it was measured from the lowest part of my whole garden.

This gives me a lot more wiggle room.

How do they define "front"? Is it with respect to the property as whole, or where the main point of access to the shed will be (where the door is)?

 

[Brdy]

How do they define "front"? Is it with respect to the property as whole, or where the main point of access to the shed will be (where the door is)?

I’m not completely sure it didn’t fully explain, although the picture that was with the article showed a garden room with the front of the building where the door is being at 2.5m and the rear being 3m, so if I were to guess I would say the front of the new structure.

 

[Mouse007]

You are not restricted to the "front" - any ground "adjacent" to it will do.

The Town and Country Planning (General Permitted Development) (England) Order 2015
https://www.legislation.gov.uk/uksi/2015/596/contents/made
Interpretation

2. (1) In this Order—
...
(2) Unless the context otherwise requires, any reference in this Order to the height of a building or of plant or machinery is to be construed as a reference to its height when measured from ground level; and for the purposes of this paragraph “ground level” means the level of the surface of the ground immediately adjacent to the building or plant or machinery in question or, where the level of the surface of the ground on which it is situated or is to be situated is not uniform, the level of the highest part of the surface of the ground adjacent to it.


I had to dig out the rear end for my workshop, gave me about 10cm wriggle room.

 

[Brdy]

You are not restricted to the "front" - any ground "adjacent" to it will do.

The Town and Country Planning (General Permitted Development) (England) Order 2015
https://www.legislation.gov.uk/uksi/2015/596/contents/made
Interpretation

2. (1) In this Order—
...
(2) Unless the context otherwise requires, any reference in this Order to the height of a building or of plant or machinery is to be construed as a reference to its height when measured from ground level; and for the purposes of this paragraph “ground level” means the level of the surface of the ground immediately adjacent to the building or plant or machinery in question or, where the level of the surface of the ground on which it is situated or is to be situated is not uniform, the level of the highest part of the surface of the ground adjacent to it.


I had to dig out the rear end for my workshop, gave me about 10cm wriggle room.

Ah yes I just reverted back to the article and was about to post this. Apologies for that, it’s adjacent to, not the front of.

I think the article got their words muddled and assumed everyone’s land slopes backwards lol. Here it is.

“Ground level is the surface of the ground immediately adjacent to the building in question. But where ground level is not uniform (eg if the ground is sloping), then the ground level is the highest part of the surface of the ground at the front of the building. Ground level must be virgin ground, ie. not from top of paving or decking.”

 

[robgul]

This is one thing that has had me thinking of lots of different designs! Fortunately I am a short guy lol so can get away with it being more of a shed than a workshop.

My plan is to go 2060mm from concrete base to top of walls, then use joist hangers to sit the roof joists flush with the top of the walls, then 18mm ply or Osb sandwiching 75mm celotex with good quality shed felt on top of that.

My garden slopes off too so need to account for that in my design to keep under 2.5m as you said.

My calculations add up to be 2171mm which leaves me over 300mm for the slope which would be the lowest point of ground surrounding the structure. I’m assuming this is where the 2.5m would be taken from?

EDIT: I have just had another look into the height restrictions and came across a handy article that states the measurement is taken from the heighest part of the ground immediately adjacent to the front of the building. This is very interesting as I thought it was measured from the lowest part of my whole garden.

This gives me a lot more wiggle room.

My 2p - you may be short but if you ever want to sell your house then a too-low shed roof my be an issue to a prospective purchaser?? I'd make it "proper height"

... years ago we went to view a house and then the door opened the 5'3" bloke's face fell seeing me at 6'4" - the ceiling heights (it was old house) were all only about 6'0"

 

[Brdy]

My 2p - you may be short but if you ever want to sell your house then a too-low shed roof my be an issue to a prospective purchaser?? I'd make it "proper height"

... years ago we went to view a house and then the door opened the 5'3" bloke's face fell seeing me at 6'4" - the ceiling heights (it was old house) were all only about 6'0"

Haha I can see where you’re coming from. I agree and have gone back to the drawing board in terms of the height as I did get confused about where the 2.5m is measured from. It will definitely be higher now, I’m going to make a sketchup design tonight.

 

[Jameshow]

If you using a insulated roof why not put in a sips roof where the joists are integrated into the insulation void. You can buy them but I'd make them using 4" polystyrene glued in between 2 sheets of 12mm plywood and screwed to 4x2 at the joints.

 

[Brdy]

If you using an insulated roof why not put in a sips roof where the joists are integrated into the insulation void. You can buy them but I'd make them using 4" polystyrene glued in between 2 sheets of 12mm plywood and screwed to 4x2 at the joints.

This is sort of what I’m planning on doing, although I can just make the big sheets of it if I sit them on top of the joists as apposed to making smaller ones to fill the gaps between the joists.

 

[Brdy]

Concrete poured this morning roughly £300 from monster mix.

One of the local cats also walked in it… typical. I will buy something to fill the holes then seal the base in a couple of weeks once the structure is up.

 

[rob1693]

Should have put some signs up with wet concrete on

 

[Pallet Fancier]

Haha I can see where you’re coming from. I agree and have gone back to the drawing board in terms of the height as I did get confused about where the 2.5m is measured from. It will definitely be higher now, I’m going to make a sketchup design tonight.

Would be interested to see what dimensions you've settled on as am currently working on the same thing for my build, and don't want to exceed 2.5m as the neighbour is a pain and I don't want them sticking their oar into a planning application. Otherwise I'd go to 3m, and have some roof storage/high shelves as well as insulation.

 

[Brdy]

Would be interested to see what dimensions you've settled on as am currently working on the same thing for my build, and don't want to exceed 2.5m as the neighbour is a pain and I don't want them sticking their oar into a planning application. Otherwise I'd go to 3m, and have some roof storage/high shelves as well as insulation.

That’s one thing I do worry about, I have lovely neighbours either side of me but not so sure about the ones behind.

I have decided that once the ceiling in the shed is lined, the highest point from floor to ceiling will be 2080mm and the lowest point will be 1980mm, which is plenty of room for a bandsaw.

The concrete base will be the floor inside of the shed so that buys me more room instead of sitting it on joists.

 

[Pallet Fancier]

The concrete base will be the floor inside of the shed so that buys me more room instead of sitting it on joists.

Also saves on extra materials to build the floor!

I'm in a catch 22 because I need to start building around the existing shed. The floor, as a result, will go in last, after the existing shed is removed from inside the carcass of the new one.* I was considering a frame on pillars or a perimeter foundation, but I suppose I could just pour the floor in last, inside the perimeter, and save the extra height of joists and extra materials.

*I saw a guy in Cork build his new house around his old one while he was still living in it, then demolish the old one and throw it out of the windows of the new one, brick by brick.

 

[Brdy]

Also saves on extra materials to build the floor!

I'm in a catch 22 because I need to start building around the existing shed. The floor, as a result, will go in last, after the existing shed is removed from inside the carcass of the new one.* I was considering a frame on pillars or a perimeter foundation, but I suppose I could just pour the floor in last, inside the perimeter, and save the extra height of joists and extra materials.

*I saw a guy in Cork build his new house around his old one while he was still living in it, then demolish the old one and throw it out of the windows of the new one, brick by brick.

Oh that is a wild way of doing things haha.

Got a bit done today, framed up and have the joists ready cut for tomorrow.

Also wrapped it in moisture barrier but didn’t take a pic.