Designing and Building Your Own Summer House

There is something magical about the promise of summer house living, even in the UK! A garden sanctuary, away from the stress and strain of the everyday world. The good life. Designing and building your own summer house is within the reach of most people. If you are handy with a few basic tools, self-building is a great option. And if your skills are not that well developed, easy to construct kits are available too. Summer living, here we come.

Designing your summer house

The design question that requires the most thought is “what do I want from my summer house”. It may sound like an obvious question, but many people neglect to give it the thought required. Do you just want a space to sit and read, with the doors open to your garden? Perhaps you would like a mini sports arena, with a dartboard and pool table. Maybe your summer house will double as an out-of-house office space?

Your design should be around the physical space you need (how much room for that pool table if you need to walk around it?) as well as factors like requirements for natural light, access, power, storage, insulation, and security. Positioning is important too. Which parts of your garden get the most sunlight or give the best views? Is there a path, or are you happy to walk over the grass?

Online design tools are available, to help you create your dream summer house, but remember that whilst they may give you a beautiful digital image, they also need to help you plan the bill of materials required, together with a plan as to how the building will physically be assembled. The more complicated your design, the more difficult it will be to build. YouTube has many videos on building summerhouses and is a good place to seek inspiration and learn about potential pitfalls.

Planning permission for your summer house

In most cases, summer houses are classified as outbuildings, and are considered “permitted developments, not needing planning permission”. They are subject to the following limits and conditions:

  • No outbuilding on land forward of a wall forming the principal elevation of the main dwelling.
  • Maximum eaves height of 2.5 metres and maximum overall height of four metres with a dual pitched roof, or three metres for other types of roofs.
  • Maximum height of 2.5 metres if within two metres of a boundary of the main house.
  • No verandas, balconies or raised platforms (a platform must not exceed 0.3 metres in height)
  • No more than half the area of land around the “original house” may be covered by additions or other buildings.

Planning permission may be required for any summer house which is closer to a public road or footpath, than the main house. If you live in a conservation area or have a listed building, permission may be required for any garden building over 10 m3. If in doubt, contact your local authority planning department.

Construction options

There are four main options to get the summer house of your dreams

  1. Design and build it yourself, from scratch.
  2. Buy a set of plans, but source materials and build it yourself.
  3. Buy a complete kit, including plans, materials, and fittings. Build it yourself.
  4. Buy the compete summer house and let someone else install it.

Much will depend on your skills, ambition, time, and money. The advantage of designing and building yourself, is you get the option of a fully bespoke summer house. Your size, your materials, your design. There is no right answer, only you know your level of skill, knowledge, and ambition. For many people, the option of building a pre-made kit is the right balance. This is especially true if you can find one that closely matches your original design needs.

Where to site your summer house?

The location of your summer house will be a mixture of practical and aesthetic considerations. Think about issues like access (for all-around maintenance) and shelter from any prevailing wind. If you plan to use it as a home office, how easy is it to get to when the weather is less ‘helpful’? What view do you want from the summer house and how much of it do you want to see from your main home? Is the noise from a nearby road going to be an issue? Are there considerations relating to your neighbours?

Do you need Electricity?

In our experience, most outside buildings end up with electricity, so it might be best to start planning and installing the cabling before you start your build. You might want things like a kettle, computer, TV, lighting, and heating. To do this you need to plan not only for a suitable in-summerhouse consumer unit and sockets but also for the armoured cable required to run from your main residence. You will need to use a qualified electrician and the work should be completed in accordance with IEE wiring regulations and BS 7671. To help reduce costs, and to ensure your garden does not get wrecked, one of the things you can do is to dig the trench into which the armoured cable will be laid. The trench needs to be 600mm deep. Routing should avoid drains etc.

An alternative is the use of photovoltaic (PV) solar panels with optionally a battery storage unit. This may give you enough electricity for lighting, but may not be sufficient for heating if that is going to be a requirement? This decision comes back to the original question of “what do I want from my summer house?”

Foundations and the base

The type of foundations and base will depend on the size of your summer house. As a minimum, you will need a base that is solid and level. This could be paving slabs laid on compacted soil, however for most installations we would recommend a solid concrete base, especially if all year-round usage is envisaged. An alternative, for a small, summer-only house is to use vertical, pressure treated wooden posts. These can be positioned in a hole at least 600mm deep, with ready-mix concrete used to secure the posts vertically. A suspended floor can then be made from scaffolding boards or similar.

For larger summer houses, the use of concrete foundations, with a waterproof membrane is recommended. This will help reduce the risk of movement, especially areas affected by soil shrinkage from tree roots. Where the ground is uneven, for example on the side of a hill, ABC Anchors have used raised ‘screw piles’ to provide the support and stability needed.

Choice of construction materials

The materials used to build your summerhouse will be a matter of personal preference. Timber should be durable as well as pleasing to look at. Each side of the summer house will be made from a series of panels or frames. The frame should be made from at least 2”x 2” (50mm x 50mm) timber, with cladding mounted on the outside. Cedar is a popular choice. If possible, treat the timber for weather proofing before construction, to minimise the risk of rot from rain or damp that might seep into the cracks. Use good quality, rust-proof screws, nails and fitting to assemble the panels!

Well-fitting windows and doors are vital for a successful summerhouse. The use of wood or PVC will again depend on a mixture of aesthetic and practical considerations. Safety glass will need to be used and, if the summer house is to be used as an all-year round office, double glazing may be a wise investment. Pre-built windows make the construction process a lot simpler.

Summer houses often use a simpler ‘flat’ or ‘pent’ roof, rather than a more traditional apex design. The roof should be covered with at least two layers of roofing felt, to maximise weather protection. Head room will be a consideration in the choice.

Insulation is something to think about, for all but the most summer-based needs. Insulated plasterboard is widely available and makes a simple and neat way to achieve a warmer environment.

On-going maintenance

Any outdoor timber building will need regular maintenance. Repainting the outside of the summer house once a year, using a quality wood preservative, should be sufficient. Deal with any water ingress as soon as possible to minimise damage. Oil door and window hinges to ensure smooth operation.

Need some help with foundations?

Here at ABC Anchors, we don’t build summer houses, but we do get involved with ensuring the best support for those that do. You can read how we helped Karen’s Childcare to create better outside facilities and how we helped Julia’s House children’s hospice support a wooden cabin on sloping land.
We wish you good luck building your summer house and a relaxing time using it. If we can be of help, do not hesitate to contact us.