How to build a modern garden sofa - with plans

For this build, I’ve constructed this beautiful outdoor corner sofa and coffee table using Iroko wood. I started with the design on CAD software, ordered the wood from a timber specialist (Woodshop Direct) and built the whole thing in my back garden.

If you’re looking for a way to add some comfortable and stylish seating to your outdoor space, building this modern outdoor sofa is a great DIY project to take on. Not only will it give you a cosy place to relax and enjoy the sunshine, but it’s also a fun way to flex your woodworking skills and create a piece of furniture that’s tailored to your specific tastes and needs. In this post, I’ll walk you through the steps to build your own garden corner sofa, complete with detailed plans and measurements to make the process as straightforward as possible.

Table of Contents

Designing the DIY garden sofa
How to build a modern garden sofa – A step-by-step guide
Conclusion
Tools required to make this DIY outdoor sofa
- Free download for detailed plans and cut list of this garden corner sofa

Designing the DIY garden sofa

The vision

Before I started this project, I needed a vision, some inspiration for what I wanted the outdoor seating area to look like. We spent hours scanning through Pinterest and other furniture images online to find our favourite style before starting the design. I wanted this project to be unique so ended up designing the leg shapes myself and combining some similar styles into the overall look of the sofa. When designing your own sofa, it’s important to select a style that you love the look of and something that will match the rest of your garden decor.

Measuring the space

The first task was to measure the space and think about the dimensions of the furniture. We discussed this together and decided on a nice deep sofa so that we could lounge on during the summer months. We also wanted a low down sofa as it gives a very modern yet contemporary feel to the space. The width of the corner sofa was also important. It had to fit in a very specific space, between the patio doors and the partitioning wall.

The sofa height

As mentioned we wanted a contemporary feel to the sofa so a low down design was important. Most seating tends to be around 45cm so we reduced this to 40cm. The cushions would be roughly 10cm thick so the top of the wooden seat would be roughly 30cm.

The sofa back rest

The back rest was also another important consideration. We wanted a slight lean rather than a 90 degree angle. The lean was calculated at 8 degrees off 90. (98 degrees when cutting the angles) This would allow for a comfortable seating position.

The backrest height was also considered and based on our existing garden sofa which we found very comfortable. The height we decided to go for was 305mm from the top of the seat cushion, 405mm from the top of the wooden seat top.

You can find the right dimensions that work for you based on what you find comfortable.

Designing the L-shaped sofa with CAD software

To help me visualise the overall design I used a free CAD design suite called Sketchup. It’s quite easy to use and helps draw the design for visual representation and detailed dimension. This helps when creating a cut list for all the materials. It also helps find the exact dimensions and angles for cutting.

Materials

For this project it’s important to use a wood that is suitable for exterior projects. I spoke with the experts from Woodshop Direct who recommended these three types of wood for this project:

Utile
Sapele
Iroko

Sapele, iroko, and utile wood are ideal for exterior projects due to their natural properties and durability. These woods are classified as hardwoods, which means that they are denser and harder than softwoods like pine or cedar. Hardwoods are typically more resistant to weathering, pests, and decay, making them a great choice for outdoor applications.

Iroko wood stored flat — Iroko timber used for this build – stored flat and dry

In particular, sapele, iroko, and utile wood have a high level of natural oils and resins that make them resistant to moisture and fungal growth. This resistance to moisture also makes them less likely to warp or crack, which is especially important in environments with high humidity or frequent rainfall.

These woods have a beautiful natural grain pattern and deep colouration that can add an elegant touch to any exterior project. They are also relatively easy to work with, which makes them a popular choice among woodworkers and DIY enthusiasts.

For our project we decided to go with the Iroko wood as it was lighter in colour to the others and fits perfectly with other similar coloured oak we have around the house.

Protecting the wood

At Woodshop Direct, their recommended choice for protecting Iroko wood is Osmo Decking Oil. This specific oil is thinner than other options, making it an excellent choice for exotic hardwoods like Iroko. Osmo Decking Oil is clear, which helps to highlight the natural beauty of the wood, while still darkening it to some degree. This darkening effect is similar to the way water interacts with the wood, giving it a richer and more vibrant appearance. By using Osmo Decking Oil, you can ensure that your Iroko wood will be well-protected and beautifully preserved for years to come.

Planning the build

As I don’t currently have access to a workshop I needed to think carefully about the build process. If you are in a similar situation then you will likely need to consider having all of your timber cut to size. This will save on complicated milling and planning services which add time and cost to the project.

This is what I did. I worked with a company called Woodshop Direct who cut and planned all my timber to size. I simply sent them my cut list and they cut everything to the exact dimensions. By using this cut-to-size service I was able to jump straight into the build and complete it within one day.

Visit the Woodshop Direct website here

I collected the wood from their workshop in Falmouth, as I’m local, but they also deliver nation wide. I had the opportunity to speak with the staff about recommendations for protecting the wood, and I found them to be highly knowledgeable and helpful. Let’s take a look at the steps.

So without any more delay, let’s get started on the build process…

Download the full cut list and 3d plans here – Free

How to build a modern garden sofa – A step-by-step guide

Step 1. Prepare your area, tools and materials

Make sure you have plenty of space to complete this build. Clear you area and make sure you have somewhere dry to work.

Collect all your materials and lay them out on a flat surface. This will help prevent them from warping or moving. Give the wood a light sand all over before you get started. The planed all round wood will likely have sharp edges which should be smoothed beforehand.

Setup your workstation. I have used a small workbench and have setup my mitre saw for cutting the leg sections of this build. Almost all of the cuts for this project will be cut at 98 degrees. So I set my mitre saw to 8 degrees.

I’ve also installed a new blade on my mitre saw. I have used an 80- tooth cross cut blade which will give me perfectly smooth cross-cuts for this project. Here’s a look at how clean the cut is with this type of blade.

Step 2. Making the sofa legs

Using the following diagram, measure and cut the leg sections. There are two different types of legs for this project. 1. The legs for the coffee tables 2. The legs for the sofa

The coffee table legs

Using the following measurements, cut each piece to the correct length. Lightly sand each of the corners and sides to clear any splinters.

I then used a pocket hole system (Kreg Jig) to create two pocket holes for each join.

Whilst clamping the pieces together is inserted and tightened the screws using my impact driver. I was careful not to over tighten the joins as this can split the wood. It’s best to use hardwood screws (coarse thread) for this job.

I slowly works my way through each leg. it’s a good idea to apply some exterior wood glue to each join before securing the screws.

The sofa leg

These follow a very similar construction method to the coffee table legs with the difference in the tapered top section which I cut using my circular saw.

Here is how I cut the tapered section at the top. My circular saw wasn’t quite deep enough for this cut but I finished it off with a panels saw. Again, each piece was sanded before moving on to the next.

cutting the garden sofa legs circular saw

With each leg cut and joined it was time to give them all a light sand with some 120 grit sandpaper.

This completes the leg building process.

Step 3. Building the coffee tables

For this step I lightly sanded each piece before continuing.

I laid all the piece flat on the floor, selecting the nicest side to be the top of the coffee table. I then measured 150mm in from each side and centered the legs. Using 70mm (4mm) screws I secured the legs to each piece of the top.

The screws are inserted from underneath so nothing is visible from the top. I drilled 3mm pilot holes before inserting the screws. To equally space out each board I used 4mm tile spacers.

attaching the legs to coffee table screws

This completes the coffee table construction. I have two coffee tables on this design.

Step 4. Building the sofa seat

The first task here was to measure and cut the cutout sections of the boards so that the legs and back supports can slot into place.

With the sections marked out I used a jigsaw, hammer and chisel to cut out the pieces.

Using 80mm screws, I joined the two corner legs and slotted the first piece into place.

I rolled the sections onto the back supports so that I could easily fix the planks from underneath. I added one board at a time and used the 4mm tile spacers for equal spacing between each board.

Repeat the above process for the other section of the sofa.

Step 5. Fixing the back supports

Without an extra pair of hands I made use of some F clamps for this part of the build. I marked out each board and held them in place with the clamps before securing them in place with some 40mm screws.

Each board was lightly sanded before I began.

This pretty much completes the build. Just two final steps left to finish and protect the wood.

Step 6. Sanding and staining the wood

The final stage of this build is to sand all the wood. I used an orbital sander for this job, starting with a 120 grit and then moving onto a 240 grit paper. Be sure to sand in the same direction as the grain of the wood so that any orbital marks don’t appear in the wood.

It’s then a good idea to wipe down the wood with a damp cloth before a final light sanding with a fine sanding foam pad.

Applying oil to exterior wood is important for several reasons. First and foremost, it helps to protect the wood from the damaging effects of exposure to the elements, including UV rays from the sun, moisture and temperature changes. Without protection, wood can become brittle, warped, cracked, and discoloured, which can compromise its structural integrity and aesthetic appeal.

By applying oil to exterior wood, you can help to prevent these issues and extend the life of the wood. The oil acts as a barrier that repels water and prevents it from soaking into the wood fibers, which can lead to rot and decay. It also helps to reduce the effects of UV radiation by blocking some of the sun’s harmful rays, which can cause the wood to fade and discolour over time.

Additionally, oiling exterior wood can enhance its natural beauty and bring out the richness of the grain pattern. This is particularly true for hardwoods like teak, iroko, or sapele, which have unique and striking grain patterns that can be accentuated with the right type of oil.

I’m applying several light coatings of an Osmo decking oil. It’s best to use a lint free cloth for this application, rather than a brush which can apply thicker layers which wont soak into the wood grain properly.

Step 7. Adding cushions to this outdoor sofa

It was quite difficult finding the right size cushions for our custom built garden sofa. This is something worth bearing in mind when designing your own sofa. Check what size cushions are available on the market and design the length and depth around these.

We were quoted over £900 for some custom made cushions which was a bit beyond our budget right now. Instead, we found some cheaper ones on eBay which are almost a perfect fit. Which was lucky. Here is the listing if you are interested: Garden sofa cushions eBay

Conclusion

Hopefully you have enjoyed reading about this build and it’s inspired you to try your own. If you love woodworking but don’t have access to a workshop, don’t worry. Order some cut-to-size timber and wait for the good weather to simplify the process.

I’ve used a few basic tools for this project which I’ve listed below.

Pallet garden sofa’s are also very popular this time of year but they don’t quite hit the mark in terms of luxury and contemporary design. That’s were this design and build come into play. A DIY outdoor sofa like this could cost in the region of £4000. You can build your own for a fraction of this cost.

Let me know what you think of my DIY outdoor corner sofa in the comments below.