How to build a garden shed

Do I need a garden shed?

If you have any outdoor space at all, a garden shed is an invaluable addition that will help keep things in order. It will quickly serve as a place for leftover potting soil, empty plant pots and other utensils. It also offers a safe and dry storage place for garden power tools such as lawn mowers, clearing saws and hedge trimmers, keeping them protected against cold, moisture and dirt so that they continue to function correctly, as well as manual tools such as spades and rakes.

It may seem like a daunting challenge, but building your own DIY garden shed just needs a little skill and knowledge and offers the huge advantage that you can adapt it to suit your needs. You’ll need to take some time to prepare, but don’t worry: our detailed instructions take you right from planning your garden shed to completing the build. Our version also has a green roof, so it's much more appealing to look at than a typical shed as well. 

Do you need planning permission to build a garden shed?

My property, my rules? Not exactly. Construction on private property is subject to regulations, and there may be some instances when building a wooden shed requires planning permission. Most typical garden sheds fall under permitted development rules in the UK, meaning planning permission is not needed – but you should make sure your plans meet the criteria. Height restrictions vary slightly depending on where the shed is located, but a maximum height of 2.5 metres will not generally be a problem.

There are a few intricacies to planning laws dependent on your exact situation, so you should look over the current building regulations before you start.

Be a good neighbour

To avoid conflict with your next-door neighbours, you should discuss your plans with them in advance. This gives you the chance to make sure that your garden shed will not cause issues with other property boundaries and will not block anyone’s view.

How to build a garden shed: preparation

Once you’ve established the rules, you can start preparing to build your garden shed. This is a substantial project that will take about 4 to 5 days to complete.

Choosing the right location

Choose a location that is easily accessible for wheelbarrows and large pieces of equipment. Choose a spot where the soil is not too wet or muddy. We also recommend you build on flat ground: although it is also possible to build a shed on a slight slope, levelling the floor requires additional effort.

Tools and Materials you’ll need to build a garden shed

STIHL tip: Get your OSB panels cut to the size you need at the DIY store.

Tools and accessories required

• Personal protective equipment
• Garden pruner (e.g. STIHL GTA 26 cordless garden pruner)
• Chainsaw (e.g. STIHL MSA 160 cordless chainsaw)
• Cordless screwdriver
• Hammer
• Carpenter's square
• Spade
• Drill bit
  
• Forstner drill bit
• Chisel
• Tape measure
• Pencil
• Spirit level
• Workbench
• Bricklayer’s bucket to mix the concrete in
• Garden roller if required
• Ladder
  

Step 2: build pile foundations

When exposed to frost, rain or heavy loads, soil can shift – and this type of movement could warp your DIY shed over time. A solid foundation helps prevent this and will mean your garden shed remains sturdy for years to come. It also means you can create space between the wood and the soil, to allow any water to run off and protect the shed from frost. There are various approaches to making a foundation for a garden shed, including building a full concrete base and using blocks. This method uses concrete piles set into the ground.

Step 3: install floor

You can now lay a floor over the foundation of your garden shed. You can use a garden pruner, like the GTA 26 to cut the floorboards to length, securing them to a workbench for cutting.

Step 4: assemble the walls

It is easier to pre-assemble each wall before installing them onto the garden shed base. We recommend you do this on an even, level surface – the base you have just built will work well. Alternatively, you could place several trestle tables together to work on.

These measurements are to create a shed with a single pitch roof, so the front and back wall are the same size (though one has the door in it), and one side wall is taller than the other. Use the 76 x 50 mm timber to build the frames; the lengths you need are given below.

Right shed wall 2000 x 1800 mm frame:

• 2x 2000 mm
• 4x 1700 mm
• 6x 600 mm (crossbeams)
  
• OSB-panels

Left shed wall (tall wall) 2000 x 2065 mm frame:

• 2x 2000 mm
• 4x 1965 mm
• 6x 600 mm (crossbeams)
• OSB-panels

Rear shed wall (slanted top):

• 6x 550 mm (crossbeams)
• 1x 1848 mm, (for the base)
• 1x 1950 mm, cut to an 8° angle at the top
• 1x 1855 mm, cut to an 8° angle at the top
• 1x 1775 mm, cut to an 8° angle at the top
• 1x 1710 mm, cut to an 8° angle at the top
• 1x 1870 mm for the top bar of the frame, cut to 8° at one end and 82° at the other (the ends should be parallel).
  

Front shed wall (slanted) with door:

• 2x 554 mm (for the base)
• 5x 454 mm (crossbeam)
• 1x 740 mm (lintel)
• 1x 1950 mm, cut to an 8° angle at the top
• 1x 1830 mm, cut to an 8° angle at the top
• 1x 1775 mm, cut to an 8° angle at the top
• 1x 1710 mm, cut to an 8° angle at the top
• 1x 1870 mm for the top bar of the frame, cut to 8° at one end and 82° at the other (the ends should be parallel).
  

Note: You do not need to angle the horizontal top bars of the two side walls because the roof joists of the garden shed will be notched at these points.

Step 6: prepare roof beams

Now it’s time to make the roof. You will need to make five rafters from the 150 x 50 mm timber. Saw the beams to a length of 2430 mm and cut the ends at angles of 30° and 60° respectively (the ends should be parallel).

Step 9: create roof edges

If you have chosen to give your garden shed an attractive green roof, you now need to make the necessary edging for the roof. This step uses various sizes of timber, as set out below.

For the front and back edges:

• 2 pieces of 170 x 22 mm construction timber cut to 2500 mm
• 2 pieces of 50 x 22 mm construction timber cut to 2450 mm
• 2 pieces of 78 x 22 mm construction timber cut to 2450 mm
  

For the tallest, left wall edge:

• 170 x 22 mm construction timber cut to 2544 mm
• 50 x 22 mm construction timber cut to 2500 mm
• 78 x 22 mm construction timber cut to 2500 mm
  

You could simply buy plants from your local garden centre or DIY store for planting on the roof of your garden shed, or, for a ready-made option, you can buy a sedum blanket that is rolled out like turf.

The last step is to fit the guttering, including a drainpipe. If you put a water butt under the pipe, you can easily collect rainwater to water your garden with.

Finished! Your DIY garden shed is now ready for you to fill up with tools and then admire your handiwork! 

Summary: how to build a garden shed

• With a little skill and knowledge, you can build a sturdy garden shed in 4 to 5 days.

• Most sheds don’t need planning permission, but there are restrictions on height and area, so be sure to check your specific situation.

• The best site for your garden shed is a spot where the ground is even, and the soil is not too wet or muddy. The structure should be easy to access with a wheelbarrow or heavy garden tools.

• Softwoods such as pine, spruce or larch are an excellent choice for building a garden shed. Floor joists made from plywood are also a good option. You should only use pre-treated wood, and be sure to maintain it regularly with the right preservative.

• Start by building a foundation using concrete, wooden beams and gravel. Then lay floorboards on top and screw them into place.

• Use a garden pruner to cut the floorboards to length. A powerful chainsaw is better for heftier beams.

• Always wear personal protective equipment while working with a chainsaw, as directed in your operating instructions.

• Build the walls individually using a timber frame construction and OSB panels. Then assemble the entire structure, screwing everything together, and install the door.

• Saw and chisel angled notches into the roof beams, then screw them to the side supports. Add battens and then an OSB panel to the roof
  Clad the outer walls with vertically mounted tongue-and-groove panelling.

• Build and install shed roof edges and green roof layers. Plant suitable plants, such as the red moss stonecrop or the caucasian stonecrop.

• Attach guttering and a downpipe.