Build a house on stilts: DIY instructions and price guide

Planning

If a job’s worth doing, it’s worth doing properly. Careful planning will make the construction phase easier, just remember not to overcomplicate it.

Forming the concept

A stilt house is a fundamentally simple concept. Four posts are anchored into the ground with sleeve sockets set in concrete, on which wooden boards are laid for the floor, planks for the sides, and a roof on top. You can either go with a classic gable roof or choose a mono-pitched design.

The extent of your planning will depend on your requirements and intentions. Is a little playhouse enough for your kids or do you need an accompanying slide and swing set? Does the whole thing need to be windproof, or do you want to leave the sides open?

Which types of wood are suitable for a self-built stilt house?

There are a few things you need to consider when choosing your wood, such as properties, cost, weight, thickness and general practicality.

If we disregard expensive hardwoods, you’ve got three classics to choose from: pine, spruce and larch. Since pine has large knots and thus a greater porousness, we can rule out this type of wood for a DIY stilt house. Spruce, on the other hand, is very suitable for this type of project, but it must be coated with a protective layer. Larch, meanwhile, is a little more expensive but doesn’t require a protective coating.

Where can I get the materials?

The easiest way to get materials is to buy everything from a DIY store. This way, you can get advice on the type of wood and protective coating you should use. Never underestimate the quantity of materials you’ll need, though, so make sure you have appropriate transport – a 7-seater family car, trailer, or van should do – to get everything back to your house.

If you know the exact materials and quantities you want to use, you can order most things online and have them delivered to your door.

What costs should I expect?

Since there are different variations of this project, exact costs are difficult to determine. The overall cost of materials will depend on multiple factors, including the size and type of construction (like the roof shape), the type of wood, and the thickness of the boards.

Below is a very rough estimate of the costs for a simple DIY stilt house construction with a base area of approximately 2m x 2m and a gable roof. You will need:

• spruce squared timber (rough sawn and still untreated), 90mm x 90mm x 2500mm: around £20-£25 each
• spruce wooden boards (rough sawn), 140mm x 23mm x 2000mm: around £10 each
• partially threaded countersunk bolts: lump sum around £20
• wood glaze: around £15 per litre (one litre is enough for two coats of an 8m² area – you can find useful calculators for this online)
• ground sleeve sockets: around £10 each
• quick-drying concrete, 1-2x 25kg bags: around £15 each
  The following table displays the costs for the simple stilt house model in our guide:

Let's go! Our step-by-step guide to building a house on stilts

It’s time to get building with our simple step-by-step guide for your new DIY stilt house. Always take your time with the project and never rush things unnecessarily. If there are two pieces of advice you should always listen to with DIY, they are: “Cut corners and you'll go round in circles” and “Measure twice, cut once”.

Initial base construction

The basic structure of your DIY stilt house will consist of squared timbers. These are used as four corner posts which link together using the wooden beams that form the floor of your stilt house. As for their dimensions and details, that’s up to you.

Laying the foundations

Since you probably don’t want your stilt house to last forever, you don’t have to overdo it with the foundations. All it takes is four ground sleeve sockets and quick-drying concrete.

To anchor your house on stilts, first dig a hole at a suitable depth and make sure the wood of your corner posts won’t stand in puddles when it rains. Then, place each metal ground sleeve in its place and fill the hole with quick-drying concrete.

This should be a good enough foundation for a normal-sized DIY stilt house. If the soil is particularly soft, seal the bottom of the holes first so the posts don’t sink down.

Strengthening the structure

The main weight on the stilts will be the floor of your raised house. As a result, the support beams need to be strengthened. To do this, use squared timbers that have been sawn at right angles at each end and attach them as floor supports to the corner posts and floor beams. Use two per corner, as the diagram shows.

Extra woodwork on the structure

Depending on your planned design, you may need to attach more beams or wooden planks to your structure, especially if you’ve planned a veranda. And don’t forget the door and floor covering!

To make the floor, simply use the wooden boards you have and cut them to fit. Remember to cut a chunk out in each corner so they slot into to the posts. Screw them to the floor joists, making sure that the distance between each board is roughly the same.

Building the roof

Building the roof is a little complicated, but it can be easily mastered with some planning. First, make a roof truss on which the roofing will be fixed. This essentially consists of two gables that are connected via a crossbeam.

When building the roof, you’ll find that using OSB boards can be a big help. They’re a suitable material to use for the gable boards or the roof covering. You can either screw them to the gable posts on the outside or attach them directly onto the roof. It will look nicer if you attach overlapping boards from the bottom to the top, not to mention it will provide extra rain protection.

After you’ve laid the boards, they must be sealed to protect against water penetration. To do this, take an angled board and screw it to the top battens of the roof covering.

Exterior walls and cladding

Now, it’s time for the outer walls. Cut the boards to size – allowing for window and door openings – and screw them onto the posts. Then, attach the frames for your windows and doors. You can make the necessary battens by sawing down roof battens until they fit. Finally, attach the bargeboards to the outer edges of the roof on each gable side.

Painting, glazing and varnishing

It’s important to protect your DIY stilt house from external influences, either by applying a protective glazing or adding a coat of paint. You can also use varnish, but it will depend on the type of wood you use.

Each method gives the wood protection, but they are fundamentally different. While glaze is like a care cream that penetrates the wood, varnish forms an impermeable protective coat. You can see how the two compare below:

With varnish, you need to decide between a water-based acrylic varnish or a solvent-based alkyd (synthetic resin) varnish. Water-based varnishes are environmentally friendly, produce less odours, and dry quickly.

Alkyd varnishes, on the other hand, are very resilient and robust. This makes them ideal for surfaces that are exposed to lots of stress and weathering. We recommend going to specialist shops and asking which wood protection products are suitable for your young ones that will use the DIY stilt house.

For spruce, you can also use wood stain to protect against the blue stain fungus. This primarily attacks coniferous woods and, as the name suggests, turns the wood a bluish colour. Protection will prevent the fungus from damaging the wood’s outer layers, which stops wood rot.

Extensions and extras for your stilt house

It’s entirely up to you how much character and luxury you build into your house on stilts. There are many possibilities for extras, such as lockable doors and windows, floor coverings, a rain gutter and even decorative railings.

Of course, you’ll also need a suitable ladder for your stilt house, but you can find instructions for that in our other guides. In this section, we’ll instead discuss extras like slides, swing, and sandpits.

Slides

A slide is the simplest addition to your DIY stilt house, since plastic polyethylene slides are commercially available from many places. The head of the slide attaches to your stilt house, while the lower end rests on the ground.

Sandpits

A sandpit is also relatively easy to add. Its ideal place is underneath the stilt house itself, as this protects children from rain and sun when they play in the sand. Check out our guide on building your own sandpit for more details.

Swings

A swing set is a little more complicated, because you must attach another structure to your stilt house. You need at least two posts that are connected by a beam, to which you attach the swing via hooks.

Can I do that? Your legal questions answered

The good news is that a children’s playground for private use doesn’t normally need planning permission. There are a few things to consider, however, such as whether you’re the owner of your home or have private use of its garden.

If you’re a tenant with a private garden, always consult your landlord before building anything. Unless something – like a tree – literally stands in your way, you shouldn’t have many problems. Even if you own the property, it may be a good idea to check with your local council to see if you need to maintain a certain distance from a neighbouring property.

In any case, if you want to build a house on stilts, it’s always a good idea to consider those around you. Talk to your neighbours about your plans as early as possible. This way, you give them a heads-up and you may just find a few helping hands!

If you want more DIY projects, we’ve got plenty to choose from! Check out our Garden, Balcony & Terrace section to find exciting ideas on how to turn your garden into a play paradise for children, such as how to build a mud kitchen. Whatever you build, good luck and have fun!