How to build a DIY playhouse the right way

Once you’ve gathered all your tools and materials, it’s time to get building! The first step is to prepare the materials for your playhouse’s structure and support frame. Start by cutting the posts, joists, beams, struts, and purlins to size until you’ve got all the timber to build a frame and a roof with adequate supports.

Label everything so you can find the right parts later. Remember to store the timber properly – keep it sheltered from the rain and off the ground.

For the flooring and foundations, you’re going to build a wooden base with holders for the posts. We recommend using thick glulam beams for the floor construction since these are the most stable and don’t warp in damp conditions.

Place the post holders in the ground and use quick-drying concrete to secure them. Depending on the size and weight of your playhouse, it may be worth using universal beams (also called I-beams) to provide extra reinforcement. Dig your foundations deep enough to reach frost-free ground – around 80cm is usually sufficient – and ensure everything is levelled so that the floor joists end a few centimetres above the ground. If you’re not a fan of this look, you can add a covering at the end.

For smart protection, you can add insulation into the flooring with hard foam boards and a vapour barrier, which are then covered by wooden planks. This is a great idea if you want to use your playhouse or garden shed in colder weather.

You’re not limited for choice when it comes to building the walls of your DIY playhouse. We’ve gone for a frame made from roof battens attached to OSB boards, which also help to reinforce the upright posts and overhead beams.

Assemble the entire wall before attaching it to the playhouse structure. Make sure you plan for windows and doors, too. For shutters, you can buy used wooden louvre doors from DIY shops and cut them to size.

You should also add insulation to your walls if you plan on using the playhouse after your kids have outgrown it. Insert the insulation as described in Step 2 between the OSB boards in your wall.

You must remember to plan your walls to allow for a sloping roof with a gradient of around 2-3cm per metre. For example, you could make your front walls 2m high and your back walls 180cm tall. Always consider the structural engineering calculations of your construction or seek advice from a specialist if you’re unsure of how to do this.

Once you’ve attached the walls, your playhouse begins to take shape. The next step is to attach the rafters by screwing them with butt joints into the purlins or, if that’s too simple for your liking, you can choose a different kind of joint. Finger joints, for instance, are great if you want a roof overhang. Using joints to connect the rafters is ideal because it gives them automatic positioning – just make sure you allow enough overhang to protect your walls from rain.

Now, it’s time to seal the roof and install a drainage system. Bitumen and rubber are great materials for waterproofing, the latter of which has become particularly popular in recent years. Rubber is the also the best choice if you want to add greenery on top of your roof – just remember to adjust your structural engineering calculations to allow for this!

Bitumen sheets and roof shingles are a cheaper alternative than rubber. They’re also easier to work with, but it’s ultimately up to you which material you choose.

To create a drainage system, attach a small rain gutter and a downpipe to the roof. If your roof isn’t too big, you could add a chain instead to help funnel the water down. This option is a lot more aesthetically pleasing.

OSB boards aren’t a popular choice for the exterior. Instead, use moulded boards connected by tongue and groove joints for the façade. To do this, attach counter battens to the OSB boards to provide support and rear ventilation. Then, attach the panels carefully without angling the boards to ensure they all fit.

Finally, decide on a colour for the façade. Apply special protective paint over an undercoat of insulating primer to maximise its evenness and attractiveness. All types of wood should be protected in this way with wood stain  or varnish – you can find more details in our paint spraying guide.