Building a Sheltered Lean-to

In recent months, many people have been trying to make more use of their gardens and outdoor areas, including constructing a sheltered lean-to for shelter and workshops.

how to construct a garden sheltered lean to

While summerhouses and garden rooms are a fantastic investment, simple structures like pergolas, gazebos and sheltered lean-tos have grown in popularity.

A lean-to is a simple structure usually added to an existing building with the rafters ‘leaning’ against another wall. One traditional type of lean-to is known by its Finnish name laavu.

Sheltered lean-tos are simple, durable structures that offer a cost-effective way to enjoy your outdoor space, until late in the evening and in the cold months of the year.

In this article, we’ll demonstrate how you can create your very own sheltered lean-to based on our step-by-step guide and photos from a recent project.

What can you do with a lean-to?

A sheltered lean-to can be used for many different things. Here are just some examples:

  • an attractive place to sit on sunny days
  • a barbeque area with seating
  • a cosy place to relax under a blanket by an outer heater in the colder months
  • a covered area right outside your shed where you can work on your DIY projects
  • an alternative workspace when you need some fresh air

How difficult is it to create your own sheltered lean-to?

Sheltered lean-tos are absolutely something you can create yourself. You’ll need:

  • some careful planning
  • a little bit of experience
  • a dab of creativity and imagination
  • a small investment in materials

You will, of course, need to invest your time as well. We would estimate that for a typical sheltered lean-to design, you’ll need between 15 to 20 hours in total. The total time required will depend on the complexity of your lean-to (most are simple designs) and how comfortable you are with this kind of project.

We also recommend not tackling this on your own – a helping pair of hands will ensure the project goes smoothly and safely.

A solid starting point

building a lean-to

In our example, the garden already benefited from a 10 x 8 Gillies and Mackay shed. A shed like this provides the perfect size and shape (not too big, not too small).

The shed was well-constructed, so it was easy to remove the fascia boards and tie the roof supports for the covered extension into the roof space.

If you don’t have a shed, you can also use part of your garage, house or another solid structure.

Tips and tricks for your starting point

  • Do ensure that you have enough space next to your starting point to build a good-sized lean-to
  • Do start with a solid structure; your lean-to will be relying on it for support
  • Don’t start with a structure that is too high or wide

Planning and measuring


Think about the perfect design to suit your garden and needs. The size and shape of your shed (or whatever you’ve chosen as your starting point) and the available space will dictate the basic design.

Otherwise, this is an opportunity to get creative and build something completely bespoke that you can enjoy for years to come.


It’s essential to take accurate measurements of your starting point and the area where your lean-to will be situated. It’s at this point that you should decide how big your lean-to will be.

Ensure it’s big enough to be used for your intended purpose, for example, as a barbeque area with seating or as an area to work on your DIY projects.

You can then use the size of your garden furniture or workbench as a rough guide and calculate the total space you need from there. Remember to include space for heaters, planters, flower pots, and other items that will provide the finishing touches to your lean-to.

Plan ahead

You can create a simple sketch or use a formal plan. However, you must be as accurate as possible when it comes to noting down the dimensions of your space and starting structure.

Planning permission

Typically, you don’t require planning permission for a lean-to as long as:

  • It’s within the boundaries of the property
  • It won’t cover more than 50% of the total area of your outside space

Tips and tricks for planning and measuring

  • Do note down your measurements accurately (‘measure twice, cut once’ as they say!)
  • Do get in touch with your local authority if you are unsure whether or not you need planning permission
  • Do ensure your plan and measurements don’t get lost or destroyed – you can use online tools like Google Docs or Microsoft Powerpoint that autosave your work
  • Do share your design with others to get feedback
  • Don’t worry about creating an amazing design or plan with intricate details; aim for a simple solid structure for best results

Materials and equipment

Your sketch or plan will provide the sizes you’ll need for your materials. Naturally, you’ll need basic tools like a saw, hammer and electric drill, along with screws and nails.

Frame and joists

We recommend using treated timber for your frame and joists because it ages well, is more weatherproof and resists decay.

Wood and timber | Building a lean-to


Most sheltered lean-tos have a simple, pitched roof that allows light and rainwater to run off. Rainwater must be able to run clear of the structure to avoid the need for guttering and to prevent damage to the wood.

Clear corrugated sheeting is ideal for the roof as it’s inexpensive, allows light in and, of course, provides shelter.

Lean-to roof materials

Thanks to their corrugations, these PVC or polycarbonate sheets have considerable strength. They won’t sag down between the posts of your lean-to. The corrugations also deflect sunlight, keeping you cool in the summer. As we’ve mentioned, they collect and expel rainwater too.

Corrugated sheets are cheaper than standard roofing sheets, come in a wide range of sizes, and are relatively easy to install.

A slightly more expensive option, corrugated Bitumen roofing is another popular roofing solution for this kind of structure. It is one of the more traditional methods of lean-to roof construction and has been known to last for over 20 years without serious maintenance required.

As an asphalt product, Bitumen tends to come in black and, as a result, will absorb heat rather than reflect it. While this may be an issue depending on the purpose of your lean-to, it makes it a fantastic source of insulation, especially during those warmer summer months.


Simple weatherboards are ideal for the rear and side frames of your lean-to. Weatherboard cladding will protect the exterior walls of your lean-to against potential damage caused by rain, snow, wind or hail. The cladding can be laid either flush, overlaid, vertical or horizontal, depending on your design, how much time you have available, and your budget.

You can coat your weatherboard cladding in stain or sealer to match your shed, home or other garden buildings.

Tips and tricks for sourcing material and equipment

  • Do ensure you select materials that are known to be long-lasting, weatherproof and can take the required structural loads
  • Do shop around independent suppliers and timber yards to get the best prices
  • Do ask for advice; people are usually pleased to help
  • Don’t feel you have to invest in the very highest grade of materials for your structure

Construction step #1: Back wall frame

It’s time to begin construction of your lean-to. Using your plan and measurements to guide you, construct a wooden frame in line with your shed or other starting structure. This will form the back wall.

Constructing a garden lean-to

Construction step #2: Side frame

Construct your side frame in the same way as the back. Add your roof joists.

Lean-to timber frame

Construction step #3: Front frame

Construct the front frame so the area remains open and accessible.

Lean-to building

In our example, a sleeper was concreted in as an attractive and strong corner post.

Timber-frame garden lean-to

Construction step #4: Cladding and painting

Clad the outside of your rear and side frames in weatherboard cladding and paint to match the shed or other structure your lean-to is ‘leaning on’. This will help it to blend seamlessly into the area.

Line the insides of your frames with plywood (painting these is completely optional).

At this point, our fascia boards were reattached to the shed as well.

Construction step #5: Roof

Add the corrugated sheeting to your joists, ensuring you leave some overhang so rainwater can run off without dripping onto the structure.

DIY lean-to garden building

Construction step #6: Electrics

In our example, electrics were added for power sockets and lighting, but this is an optional step.

Lean-to with electrics

If you plan to spend a lot of time in your lean-to (for example, working or doing DIY), you will find access to power beneficial.

There are several lighting options that don’t require mains electricity, including solar power.

Please avoid taking any risks when undertaking this step and contact a qualified electrician if you are unsure or need some help.

Garden lean-to building

Shelving and finishing touches

This step is one of the most enjoyable as most of the hard work is done. It’s time to decorate and personalise your new, self-built structure.

In our example, we have added shelving, plants, and comfortable garden furniture.

And the next step? Time to relax and enjoy the fruits of your labour!


Need help with a garden project?

We can help you to make the most of your outdoor space to suit your lifestyle. Whether it is a child-friendly space, an entertaining area for friends and family, a low maintenance garden, a space to grow plants or any combination of these, we have the expertise to help you enjoy your outside space to the fullest and for longer periods of the year.

Contact our friendly team for help and advice.