Forest Garden

Buying guide to Summerhouses

A Summerhouse can really add the finishing touches to your garden, providing an extra room that allows you to make the most of your garden and extend your summer. Summerhouses can be used as a space to escape to, somewhere to sit and get lost in a good book, enjoy a meal or do some work on the laptop. They can also make great hobby rooms.

With a number of different styles and constructions available, here are some handy tips on everything you need to know when you’re shopping for a Summerhouse.

Think about what you want to use the Summerhouse for.  Summerhouses make a great addition to your home at a cost-effective price. They’re relatively small and the buildings aren’t insulated – if you’re after a fully functioning year-round office or a gym with lots of space then you should look at alternative Garden Rooms or Log Cabins on the market.

Think about the available space you have in your garden and what you want to use the Summerhouse for.  Think about which way it will be facing and how many windows you want.

When shopping for a Summerhouse make sure you look at the specification details – you’ll need to know the footprint of the Summerhouse so you can get the base correct but make sure you take into account extra dimensions such as any roof overhangs or verandas. Check what area you get inside and outside of the building.

You don’t usually need planning permission for garden buildings or structures, as long as they are used for a domestic purpose related to your house. 

Most garden buildings fall into the category of ‘permitted development’ projects, but it’s important to check that your Summerhouse and where you’re positioning it doesn’t contravene any of the rules that apply to these permitted development projects.

It’s also worth thinking about your neighbours and if they’d have any objections. As a quick guide:

  • If your building will be within 2m of the boundary with your neighbour then you need to make sure that the maximum overall height of the building is no more than 2.5m, if this is the case you would potentially need planning permission.
  • If the building is more than 2m from the boundary with your neighbour’s property then the building can have a maximum eaves height of 2.5m (and a maximum overall height of 4m for an Apex roof and 3m for a pent roof)

Here are some other key points:

  • The Summerhouse should be used for domestic purposes only.
  • It should not be designed to provide sleeping accommodation.
  • The ground area covered by the Summerhouse and any other buildings within the boundary of the property, excluding the original house, should not be more than 50% of the total area of the property.
  • No part of the Summerhouse should be positioned in front of the principal or side elevation of the original house that faces onto a road.

Apex Summerhouses

A Summerhouse with an Apex roof means there is a ridge running along the length of the Summerhouse with the roof sections sloping upwards from either side of the eaves meeting at the ridge. This type of Summerhouse is a popular choice because of its versatility and practicality as well as its traditional and attractive appearance.

Reverse Apex Summerhouses

A Reverse Apex Summerhouse is similar to an Apex Summerhouse, the main difference is that the doors and windows are situated on the longest side of the building. The highest point of the Summerhouse will run lengthways.

Corner Summerhouses

A corner Summerhouse is effectively a 5-sided garden building which tapers back to fit neatly into a corner of your garden. With a pitched roof for water to run off, these buildings make effective use of space which may otherwise have gone to waste.

Depending on the use of your Summerhouse and how much time you will be spending in there and your budget it is worth considering the differences in the ways they are constructed and what that means for the building.

Overlap SummerhousesOverlap Construction ExampleOverlap Diagram

This traditional rustic style Summerhouse is created with overlapping boards to allow rainwater to run off. A square cut overlap timber board construction allows flexibility and movement of the timber. As temperature and humidity levels change from season to season the boards will shrink and expand.

Often the most cost-effective style of wooden Summerhouse, it is reliable and long-lasting. Overlap boards do not form a closed seal so they can be more prone to moisture and draughts. Forest Garden Overlap Summerhouses are made with 7mm thick boards.


Shiplap SummerhousesShiplap Shed ExampleShiplap Tongue Diagram

Designed to last and made of smooth-planed slow grown kiln dried timber. Shiplap Summerhouses use interlocking Tongue & Groove boards that feature a scalloped profile at the top of each board which gives a distinctive and traditional aesthetic. The tongue and grooves slot into each other to create a reliable weatherproof joint, less likely to bend and warp. Forest Garden Shiplap Summerhouses are made with 12mm thick boards.




Tongue & Groove SummerhousesTongue & Groove Construction ExampleTongue & Groove Diagram

Designed to last, these premium Summerhouses feature interlocking Tongue & Groove boards that have a flat profile for a contemporary look. The tight-fitting nature of the construction offers good protection from wind and rain penetration. This cladding is secure and durable and boards will often be thicker than other types of construction. Forest Garden Tongue & Groove Summerhouses use 12mm, smooth-planed slow grown kiln dried timber boards.

Dip Treated Summerhouses

The timber used in these Summerhouse constructions is finished with a factory applied treatment which provides some initial protection against fungal decay. This is a dip treatment which means the timber has been immersed in the treatment solution – timber is dipped into a tank containing preservative which is absorbed into its surface. The timber is removed and left to dry. 

A Summerhouse with this type of finish will need to be re-treated every year to protect the timber from rotting. Dip treated products normally have a golden brown/amber appearance when new, but this will fade over time. Forest Garden Dip Treated Summerhouse come with a 10 year Anti-Rot guarantee.

Pressure Treated Summerhouses

If you’re looking for a Summerhouse that requires less maintenance then Pressure Treated Summerhouses are a great option, there is no need for annual re-treatment. These Summerhouses have the anti-rot solution forced into the cellular structure of the timber at high pressure to give them greater resistance to rot. Timber is loaded into a tank and a vacuum empties it of air. The tank is then flooded under pressure with preservative, the preservative is drawn deep into the timber before it is left to dry. 

Pressure Treated Summerhouses have a more natural timber colouration and will blend into their surroundings. The treatment can leave a greenish tinge on the timber when new, this is normal and will grey over time.  Forest Garden Pressure Treated Summerhouses come with a 15 year Anti-Rot guarantee.

What about paint?

We think that Summerhouses really come to life when they’re painted.  Make sure you use a suitable high-quality timber paint suitable for use outdoors with weather resistant properties. We currently love the range of shades Thorndown paint have on offer.  After installation, we recommend that you let your building settle in its environment before painting straight away.


Some garden Summerhouses use hardwearing sheet material such as OSB (Orientated Strand Board) for roofs and floors, but some of the more expensive models have boarded floors which make for stronger construction and mean the floor can bear more weight.

Summerhouses should always be installed onto Pressure Treated bearers which enable air circulation under the floor and prevent the floor itself from coming into direct contact with the ground. Without them, damp would penetrate the floor and rise through the timbers causing the wood to rot. When shopping check that bearers are included with your Summerhouse or if they need to be added in as an extra.  Forest Garden Summerhouses all come with Pressure Treated bearers.


When shopping for a Summerhouse consider the number of windows you require – how much light do you want in your building, do you want normal windows, ¾ length windows or windows that run the full height of your Summerhouse. Do you want windows along the front of the building or at the side too?


Look at the width of the doors, most Summerhouses come with double doors so you can open them wide and enjoy the views of your garden.

When positioning your Summerhouse you need to consider a number of different factors. If you intend to access it frequently you may want to consider building it close to your house. You may want your Summerhouse to be in the shade to avoid overheating in the height of summer, think about when you’ll be using it most and where the sun will be.  Consider the risks of falling branches and rotting leaves on your Summerhouse over the years.

Never locate your Summerhouse in an area that could flood with heavy rainfall. Standing water will accelerate the rotting process which may affect the stability of your Summerhouse in the long run.

The majority of Summerhouses require self-assembly and you’ll usually need at least two people to install it safely, ensuring you always follow the instructions provided with your shed. Assembly is relatively straightforward for someone with competent DIY skills though it is important to get everything aligned properly before screwing it together and screw holes should be pre-drilled to avoid splitting the timber. Forest Garden also offer an installation service for all Summerhouses in the range.

You’ll need a solid, level base before installing your Summerhouse. Concrete, paving slabs laid on sharp sand and hardcore, or timber foundations, can all be used. See our Base Preparation Guide for more information.

That depends on what you want to use the Summerhouse for and the time of day you want to use it. If you do decide you want to have mains power installed this should be done by a professional electrician.

  1. Select the size and shape that best suits your garden, think of its position and which way it will face in your garden.
  2. Think about how light you want the Summerhouse to be, how many windows do you want, how big do you want the windows and where do you want them to face.
  3. Always check the exact size and technical spec of a Summerhouse, especially if you’re buying online – check the height as well as any overhangs or verandas. What area do you get inside and outside of the building?
  4. When making your purchase, think long term. A cheaper Summerhouse might be tempting in the short run but you may end up needing to replace it sooner, so go for the best Summerhouse you can afford.
  5. Think about what you will be using the Summerhouse for and how much time you’ll be spending in there – understand the different styles of construction and how the timber in your Summerhouse will behave as the seasons’ change.
  6. Pay attention to the treatment on your Summerhouse and understand if it means you’ll need to re-treat annually.
  7. Think about painting your Summerhouse.
  8. Make sure that the Summerhouse comes with a guarantee.
  9. Before you start to build your Summerhouse you need to ensure that you have a firm and level base on which to build it.
  10. Consider if you have the relevant DIY skills and equipment to build your Summerhouse. If not consider a tradesman or an installation service.