How to build your own shed from scratch

A question I’d asked myself for some time was, can you build your own shed cheaper than you can buy a flat pack one?

In short, yes you can, and you can even make it a lot nicer!

In this post I’m going to show you how I achieved this, including the tools required and where I sourced the materials. You’ll find a step by step guide, packed full of photos, of how to build a garden shed from scratch so you can create your own custom garden shed.

I’ll also share a cost comparison between building your own shed from scratch vs building a flatpack shed, which I recently tested. Discover some helpful tips at the end on how to cut the cost of building a garden shed so you can save as much money as possible on the materials you’ll need.

(If you’re in the wrong place and need help to build a flatpack shed then I have a guide on that too!  Click to learn how to build a flatpack shed)  A shed is just one idea in a long list of garden ideas to help improve your outdoor living space.  Take a look at my Summer Garden Makeover post for more amazing DIY projects.

Here’s the shed I built from scratch.

IMG_0868

How to build a custom garden shed from scratch

Building a shed from scratch using your own materials and not using a flat-pack is totally achievable. This is the great appeal of a self-built garden shed – you can build it to the exact size you require and you’re not limited by pre-made sized sheds.

Researching thoroughly will help prevent silly mistakes and wasting money.  It’s also handy to learn about different types of shed, the types of cladding, roofing and framing so you can choose how you want your bespoke shed to look.  To do this I searched online to view the various styles using websites such as Pinterest and even just Google images, as well as looking at this shed guide which gives you an idea of the different types of sheds available and what they look like.

I did a lot of research online and I already had a lot of the skills needed.  I spend hours each week reading articles online and watching tutorials to teach myself how to build these sorts of things, such as checking out online guides on how to build a shed as well as conversing with tradespeople when I can to pick up helpful tips and tricks.

Keep reading to find out how to build your own DIY shed using my step by step guide, photos from start to finish and lots of helpful advice.

First, let’s get a couple of the most common FAQs out of the way that everyone asks.

Planning permission for garden sheds

Before you get started you’ll need to be aware of any building restrictions, so be sure to check the UK planning portal.  Further more you can always check with your local planning department to double check these restrictions and get relevant guidance.  Here is a quick breakdown for outbuildings that are considered permitted developments.

  1. On designated land, outbuildings to the side of the house are not permitted development.
  2. Outbuildings are not permitted development within the grounds of a listed building.
  3. In national parks, the Broads, Areas of Outstanding Natural Beauty and World Heritage Sites the total area to be covered by any outbuildings more than 20 metres from ANY WALL of the house must not exceed 10 square metres to be permitted development.
  4. Outbuildings are not permitted development forward of the principal elevation of the original house.
    The term original house means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date).
  5. Outbuildings and other additions must not exceed 50% of the total area of land around the original house. Sheds and all other outbuildings (see intro) and extensions to the original house must be included when calculating this 50% limit.
  6. To be permitted development, any new building must not itself be separate, self-contained, living accommodation and must not have a microwave antenna.
  7. Outbuildings must be single storey with a maximum eaves height of 2.5 metres and maximum overall height of 4 metres with a dual pitched roof, or 3 metres in any other case.
  8. If the outbuilding is within 2 metres of the property boundary the whole building should not exceed 2.5 metres in height.

Tool list

You won’t need a long list of complex tools to complete this job but here are some essentials that will make your life a lot easier.  I’m a fan of the Dewalt XR range of tools because I can use the same batteries across the range and product quality is second to none.

Materials List – See comparison chart near the end of this article for costs

Here’s a list of materials I’ve used for my shed including links to where I purchased them:

Save money on tools and materials

I’ve been using a cash back site like Topcashback for all my tool and material purchases which has generated me about £950 since joining a couple of years ago.  That’s quite a reasonable saving bases on purchases I would have made anyway.  Here’s a screen shot of my savings to date:

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My wife has also been using Topcashback for all our day to day household spending and has generated over £1200.  More than enough for a great holiday for us both.  We added to Topcashback browser extension so we never miss a deal.

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If building your own shed from scratch isn’t quite right for you then consider a flat pack building from Robert Dyas


Learn how to build your own shed online with my step by step guide

So here we go, how I built my DIY shed in detail…

The shed size I decided to go for is 12×10 ft. or 3×3.6m and 2.4m tall. (To the top of the eaves.)

Shed Build 1

How I built the wooden shed base

  1. Measuring and clearing the space.  The first task was to clear debris and begin to level the ground.  I marked out the size of the shed (12×10 ft. or 3×3.6m) to start just using a tape measure and four stones.  I then began to shift soil and dirt manually from one side to the other until it looked level-ish.
  2. With a relatively flat area to work on I began to mark out the ground using a tape measure, 4 sticks and string.  To make the rectangle equal and evenly square I measured from corner to corner until each length was the same.  It was at this point I had some further levelling to complete.  Using a long piece of wood and large spirit level I was able to shift more soil to make a nice even surface to work with.Shed Build 2.JPG
  3. Using reclaimed slabs from a friend I placed one in each corner and one in between each of these.  These slabs would form the main support for the base and shed.  To ensure a solid surface that wouldn’t shift I dug a 6 – 10 inch square hole under each slab.  This hole was then filled with hardcore, sand and then topped with cement before gently laying the slab on top.
  4. Mixing cement – this is quite simple.  You can mix this in a wheel barrow, cement mixing tray or a cement mixer if you have access to one.  You’ll need some cement, sharp sand and water to complete the mix.  Start by mixing the cement and sand. (Look for about 1 part cement to 4 parts sand, this doesn’t have to be an exact science, just roughly)  Finally start adding bits of water whilst mixing until you have just enough for a wet mix.  Too much water will weaken the mix.  Google it if unsure.  For this build and enough cement to secure 8 slabs I used 1 X 25kg bag of cement and 4 X 25kg of sharp sand.Shed Build 4
  5. I used the 3m & 3.6m C16 timber and a spirit level whilst laying the slabs to ensure an good level frame for the base.Shed Build 5
  6. Leave the cement to go off for 24 hours before adding any additional weight.
  7. I then added an additional 6 slabs for further support but didn’t cement these in. Just laid on a nice level hard surface (some spare sand I had lying around mostly).Shed Build 6
  8. The next task was to screw all the lengths of wood together with 75mm x 5mm screws.  As you can see above I have used two of the 3.6m C16 and five of the 3m C16 construction timber to build the base frame.
  9. I then worked into the night to strengthen the base support even further with some of the CLS timber.Shed Build 8Shed build 7
  10. I had to ensure the cross supports were in the right place to fit along the edges of the OSB board I was laying as the floor.  These measure 2440mm x 1220mm and are 18mm thick.  I went for 18mm rather than a thinner 12mm board for extra stability.

I used a circular saw to cut the OSB board to the correct size.

So that’s pretty much it for the base.  Before installing the walls ensure you cover the base with a waterproof covering. Wrap it around the edges and tuck it under the base to provide a water tight seal.

How I built my own custom shed

  1. The first step was to create the wall frames using the 3m and 3.6m C16 and CLS 2.4m timber.  I also used the 90mm square posts for the corners (2.4m in length).  These frames were simple to create and will act as the supports for the log lap cladding.  My walls measure 2m tall so simply measure, cut and screw the parts together.  Each baton will be spaced roughly 600mm apart.shed1shed2shed3shed4My little helpers.  Couldn’t have done it without them.shed5
  2. I also stapled waterproof sheeting over the frame to add that extra level of protection from the elements.  You may choose to add a breathable membrane but this will add about £80 to the final price.shed6The reason I used 90mm posts for the corners was so that I could mount the walls about 19mm in to allow for the cladding to be mounted flush.  The four corner posts are not secured to the floor.  Stability for the frame will come from the stud walls which are screwed into the floor and posts.  You could also add some 9mm plywood to the frame to add some stability.  To do this I would mount the corner posts with a 2-5mm overhang on each corner, mount the walls 9mm in from each edge and when adding the cladding you can overlap the base to add a little more protection around the bottom of the walls.
  3. On with the cladding.  I purchased my log lap cladding from a company on eBay.  Click here to go to the listing. (Remember to get cash back by clicking here when shopping on eBay to save money on your eBay purchases!) Each piece had to be cut to length using a mitre saw. For the eaves section at the top of the walls I used a jigsaw to cut out notches where the rafters came down.  The great thing about this stuff is it just slots together and it’s then screwed to the frame in 3 locations on each board. 40mm x 4mm screws.  You can also consider going for the thicker 38mm loglap which can be found here. cladding1cladding 2
  4. The roof was next and shaping the rafters the first challenge.  I decided on a 15 degree angle on a dual pitched roof so had to make a suitable join to span a 3m space.  This pitched roof not only needed to support the weight of the roof but also my body weight as I climbed up to attach the felt.  to strengthen the rafter join I cut some triangle shapes out of the off cuts of the 18mm OSB flooring.  Additionally I used the off cuts of the 2×3 batons to further strengthen.  I tested each one of the rafters by hanging from it before continuing. I completed 7 of these in total and cut out grooves either end to sit into the top of the wall frame, screwed in with 75mm x 5mm screws.roof1roof2roof3roof4roof5
  5. At this point I was running out of time.  I had one day before some heavy rain was due so I decided to crack on with the rest of the roof to ensure protection of the rest of the untreated wood.  I decided to extend the roof 600mm out the front to add a small element of protection from the weather. this was a straight forward process, as pictured.  This was also time to cut the top off the 90mm square posts.  I used 11mm OSB board for the sheet materials on the roof and required 6 of these to cover the lot. Once all these had been cut a screwed into place it was time to add the felt.  I required 2 x 10m rolls to cover the roof and this was cutting it fine.  In hindsight I would have shortened the eaves on either side to allow a greater overlap on the felt.  Used 10mm tacks to secure.

Building the front part was the next step, having to make a slightly different frame to support the window and doors.  To save money on a window I searched locally on Facebook Marketplace and found something suitable for £30.  Bargain!  The Window is simply screwed in from the side.  Open the window and drill some pilot holes before setting in the screws.front1front2front3front4front5front6front7front8

  • I’m almost there with the final step being the doors.  I kept this simple with a frame and some vertical mounted log lap. Easy!

  • The final steps were to add some trim (facia) to the sides of the roof, fit a handle, lock, motion sensor light and paint the whole shed.  Now all that’s left to do is add paving, a path or some decking.

    img_0868

    Note – If you are planning to add significant weight to the sides of the shed, inside or out, it’s worth adding some diagonal supports to some of the wall to prevent the shed from leaning to one side.  To do this simply cut a 45 degree angle on the 3×2 wood and cut to size in-between the horizontal wall posts.

    Below is a comparison in cost between the two builds.  Hope you found this useful.

    Is a flat-pack or self-built shed cheaper?

    As I purchased and built a flat-pack shed last year, I have recent pricing and build experience to share as a comparison.  Both measure 12 x 10 feet (360 x 300cm) approx.

    The two key differences and probably the biggest saving was the base.  One a solid patio style base and the other a lifted wood frame base.

    See the breakdown of the full costs for each shed type below to see which was cheapest!  Can you guess?

    Cost comparison between flat pack and DIY shed

    Screen Shot 2018-09-27 at 20.45.13

    More about the BillyOh flatpack shed

    This blog post is all about how I built my own shed from scratch, but if you are interested then the flat-pack BillyOh shed was purchased from Garden Buildings Direct.  To read more about the flat-pack shed you can see my build process by clicking here and here is a handy link for a BillyOh discount code!


    How to save money when building a shed from scratch

    Sheds are pretty expensive and you can definitely save a bit of money by building your own from scratch as my own experiment shows, but here are some more ways to cut the cost of building your own shed:

    1. DIY

    The most obvious way is to do it yourself.  If you believe you have the basic DIY skills and woodwork knowledge required then you’ll save a small fortune completing the job yourself instead of hiring a tradesperson.

    2. Use TopCashback

    Whether you are purchasing your materials from eBay, B&Q or Wickes, there is nearly always money to be saved in the form of cash back.  Simply click through to the retailer from the TopCashback website when making your purchase and you’ll get some money back at a later date.

    3. Join the B&Q Club

    If you’re not already a member then the B&Q Club is well worth joining, especially if you spend a small fortune in there on a regular basis like I do!  Almost every time I shop and scan the card I receive an email shortly after with a discount code for my next purchase.  Quite often I’ve had £5 off a £50 shop and £10 off a £75 shop.  Nearly every time I shop there I have a discount code to use and the savings really add up.  Click here for the B&Q Club.

    4. Buy combo pack tools

    If you don’t already have the tools for the job and can’t borrow them, then look out for great multipack and combo deals.  For instance if you need to buy a drill and impact driver then it’s much better to buy them as a set like this Dewalt drill and driver set rather than buying them separately.

    5. Use the same brand of power tools

    Using the same brand of power tools means you can interchange the battery packs, instead of needing separate ones for each brand of tool.  It makes things way easier and creates less hassle once one is knackered or if one runs out of power.

    6. Buy in bulk

    Rather than ordering bits and pieces from all over the place, see if it makes more sense to buy in bulk from one retailer and avoid delivery costs.  For example, if you spend more than £300 in one go online on big and bulky items then you’ll get free home delivery from Wickes.

    7. Finally, the most important rule of all to save money – measure twice and cut once!

    I hope you have found this article helpful and good luck if you are building your own custom shed.  They can definitely look a lot better and make you feel more proud!

    Turn your shed into a garden office

    I’ve recently completed a post about how I extended this shed and insulated it.  I’m basically turning it into a garden office or garden room to enjoy all year round.  We will be able to use this space as an extension to the house, a quiet work space or a room to chill out and get away from the day-to-day.

    img_3052

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    How to build your own shed from scratch

    57 comments

      • Hi, it’s not secured to the floor itself. The walls and roof rafters support these posts to prevent them from moving.

    1. Hi Ben What wood material did you use for the outside of your shed? I’ve read through but, I don’t see what type of wood or brand it is and if this is tongue and groove. My husband has built our shed and we are deciding on the outside covering. We live in Ontario, Canada. Thank you, Deborah

      • Hi Deborah. It’s called loglap timber cladding and comes in a number of different sizes. It’s a type of tongue and groove with rounded sides. Not sure if this product is available in Canada

    2. Hi Ben, your shed is 360 x 300cm But in the shopping list the longest wood you list is 2400mm. Did you have to join the wood for base and walls? If so, how did you do it?

    3. Hi Ben, please can you tell me what you used theCLS 38x63x2400 for ?
      And also C16 3×2. ?
      Thanks
      Allan

      • Hi Allen, I’ve just updated the post so hopefully it’s a little clearer now. Basically the C16 was used for the base frame main supports and the wall frames top and bottom pieces.

    4. Hi Ben , very helpful informed process of building a shed thanks , just one thing what is the height of it please ?

    5. Hi Ben, great write up. It’s inspired me to build my own! I have a sticking point. Where my shed will be, the back and one side will be against my red brick house walls. I don’t know whether to sit hard up against the brick or leave my stud wall away from the brick and then if so what to clad it in as it will be out of sight I don’t want to ship lap it.

      • Hi Dan. I guess you could join the shed to the house but you will need to research suitable flashing materials to ensure a water tight fit. The easier option is to build away from the brick walls. the cladding you then use will be dependant on what you are using the shed for. Maybe just a cheaper tongue and groove cladding. I would advise enough space to get down the sides, firstly for building access and secondly maintenance reasons.

        • Cheers Ben, I’m going to build away from it. Wood is bought, frame work begins tomorrow! One question, did you pre drill holes for the 5×75 screws? I’ve read conflicting opinions.

    6. Hi Ben,

      I’ve basically followed your instructions to the letter and I’m at the point of finishing the cladding but haven’t chosen how I’m going to paint/stain the cladding.

      Could I ask what you used and what you’d recommend? I’m not looking to change the colour of the cladding much as I like the grain, maybe a few tints darker like on yours.

      I’m thinking a stain but I know they can be tricky and not exactly weather proof.

      Thanks,

      • Hi Issac, you could try a clear water protective treatment such as ‘Barrettine Log Cabin Treatment’. It can be expensive but it’s one of the best for clear shed protection. You could also try a decking oil, like ‘Ronseal Ultimate Protection Decking Oil’. 5L should be plenty. Regards, Ben

        • Hi Ben, very informative and helpful write up for building a shed. By far the easiest to follow guide I have found and the one I intend to use when (if) I get around to replacing my shed.

          I’m curious about the edges of the OSB that makes the floor. Due to the 19mm inset you have between the walls and the corner posts, and therefore the flush-fit cladding, the cladding stops before covering this edge. Does this mean the edge of this OSB exposed to the elements?

          Thanks,
          John

        • Thanks John.
          I’ve laid a waterproof membrane on the floor to protect the flooring and also allowed a slight overhang for the cladding. Given the chance to do again I would probably do it slightly differently. But not exactly sure how at this point.

    7. Hi Ben, have you altered the materials list at all? A couple of weeks ago it contained hyperlinks to the B&Q products but now it just has a number in each apart from the cladding.

      • Hi, I might have edited but the links should still work for each of the products listed. Try reloading the page to see if that works.

    8. Hi Ben
      Great description. How did you power the light – did you run mains or is it solar/battery?
      If mains – any particular advice on getting power to the shed – ducting etc?
      And did you clad internally or just leave the plastic exposed?

      • Hi Steve. I’ve run mains to the shed. You’ll need a qualified electrician for this or to sign it off. You’ll need an armoured cable in ducting in the ground or along the fence. You’ll need to read into this yourself as it will depend on how far you are going and power requirements. Easier to get an electrician to install.
        No cladding internally yet but will be insulating and plasterboard soon.

    9. Really appreciate the time taken to create this guide. I’m just designing a smaller version of your shed and working out what materials I need, so quick question – what timber did you use to make the roof trusses? Was it the cls 63mm x 38mm? Thanks

      • Yes, that’s correct. You can go for a 2:4 if you want it a bit stronger but the 3:4 should be fine with 600mm intervals.

    10. Hi Ben. Great guide. Going to build my own but only 2400mm wide. I’m having trouble working the length of the rafters for my size shed. Did you use any sort of calculation when working out the length of your rafters or could you tell me how long each side of the rafter needs to be. Thanks again. Mark

      • Hi Mark. I just guessed the size so it’s really up to you. There is no precise science behind it but take into consideration the size of the boards for the roof which normally come in 2440x1220mm size. The less cutting the easier. 👍🏼

    11. Hi Ben
      Would you say these build materials are sufficiently robust to use the shed as a bar with a wall mounted tv. I’d intend on putting insulation inside and some interior panelling on top of therefore. Also is the wood pre treated or did you treat after – as the final shed looks painted or stained.
      Thanks!
      John

    12. Hello, great post thank you! What timber did you use for the doorway frame? What timber for the door frames?Any bracing aside form the vertical loglap on the doors?

      • Hi, I would put a diagonal brace on the door frame and then lap on top. This will prevent and warping. The timber is the same as the walls. You might also do the same on the walls depending on whether you will be putting any weight inside.

    13. Hi Ben

      Great write up of your build, very informative.

      I’m thinking of doing something similar – can I ask how your shed been for condensation and damp so far?

      I’m wondering about putting the polythene sheet under the base frame make a difference – it would stop damp rising up from underneath but allow ventilation. Also possible to infill gaps in the frame with insulation perhaps.

      Andy

      • Thanks Andy. I made sure there was ample ventilation in the eaves which prevents any condensation build up. I’ve also just started building an extension and insulating so will write this up and share at some point.

    14. Hi this is amazing and what a great find. being a novice with a modicum of DIY experience it fills me with confidence. The one thing that I’m most concerned with is getting it all level as the garden has a small degree of slope. How do you achieve that with those corner pads?

      Also is it worth filling the gaps in between the floor frame with something so I don’t get vermin hiding\living underneath.

      Also is the floorboard treated or weather proofed in any way.

      I may be getting a bit concerned about obviously small things here.

      Thanks again

      • Try levelling your garden by digging out one side and raising the other. You might want to make a raised base for this. Try my decking post to see how this is done. https://wood-create.com/2020/04/13/how-to-build-your-own-decking-area/
        If you can fill the gaps then it’s probably a good idea. I however like that I have provided shelter for hedgehogs etc.
        The floorboards are not treated but they are covered with a waterproof barrier which prevents rot.

    15. Hi Ben. Bit of a random question as I am a novice when building things and this is my first large build. Any chance you can tell me what size screws you used and where to use them?

      • Mostly used 80mm screws which are used to join the timber frame. Simply pilot hole drill into the top and bottom rail to secure the upright posts.

    16. Hi Ben, thks for the guide, really informative. I’ve started building my shed today based of your spec. So far got the base/floor done. Can I ask what the height is between the top of your wall frame plate to the top of the roof rafters? I’m guessing about 30 cms to allow for the roof osb and the depth of the floor? Also the plate height is 2m not the stud height? Cheers Chris.

      • Hi Chris, I can’t remember exactly but the overall height is 2.4m so I would say you’re pretty close with your calculations.

    17. Hi, great post. Given me lots to think about.

      On the cladding you mention in comments above that you would do it differently. I’m thinking of making the frame flush with the posts and then boarding over posts and finishing with beading at the corners. This will also allow it to go over the floor at the bottom for extra protection. Having already build yours, any reason why this wouldn’t work?

    18. hi ben ive just found your site on how to build a shed from scratch and im going to start my one in july as weather should be good the difference is my one is going to be a long shed as opposed to square the overall lengh will be about 8 mtrs dom you think i will be able to get timbers that long or will i have to join them regards chris

    19. Hi Ben,

      Apart from the fence posts, it looks like all the timber you used was untreated. Is that because it was all going to be covered by the cladding and so not exposed to the elements? Did you treat any of the timber with a preservative yourself? E.g. the timbers of the base which sit on the slabs?

      Did you put some kind of flooring on top of the membrane to protect it from the wear of trampling feet?

      • The timber isn’t treated as it should be protected from the elements due to the moisture barrier. It would however be a good idea to treat the wood for extended protection.

    20. Ben, great write up and instructions. You have used a membrane on the inside walls. Did you clad this internally also ? What covers the plastic membrane?
      John

      • For the internal of the shed there is nothing but the timber frame. It’s a simple build with only a frame, plastic membrane and the cladding. You can choose to add an internal wall made of ply, OSB or even plasterboard.

    21. Ben, I have read this twice and looked at the photos. Where does the membrane go? It is on the floor in some photos and tucked under the front and then it is just tucked under but not on the actual floor. On the walls does it just stay exposed from the inside?

      • Ideally the membrane will cover the floor and tuck right underneath before you add the wall frames. Then the membrane on the walls will go right down to the floor. (tuck under is desired). The idea is to prevent moisture becoming stagnant under the base.

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