If you’ve been dreaming of a spacious timber garage – big enough to store a few cars, house a workspace, and store all your garden furniture – then you might be wondering how large you can go. In Scotland, two main factors determine how big your garage can be: permitted development rules and Building Control regulations.
In this guide, I’ll explain what permitted development and Building Control are, how they impact the size of your Garage, how to apply for a building warrant, and how G&M navigate Building Control.
What is Permitted Development?
Permitted development allows you to build a structure in your garden without applying for planning permission. There are several rules you need to meet for a building to be considered as permitted development. These rules are primarily concerned with where your building will be located, its appearance, and its impact on your neighbours.
We have a handy checklist that you can use to determine whether your timber Garage needs planning permission:
If your wooden Garage meets all these requirements, it is considered a permitted development. This means you’re unlikely to need planning permission.
Further reading: Do all wooden Garages need planning permission?
Is 50% of your back garden undeveloped?
The only permitted development rule that applies to the actual size of your wooden Garage is that 50% of your back garden needs to be left undeveloped. The 50% includes your proposed wooden Garage, plus any existing developments such as sheds, greenhouses or outbuildings.
Example 1: Within permitted development
If your back garden is 100m², and your proposed Garage is 25m², plus you have a shed that’s 5m², then the total developed area is only 30m². This leaves 70% of the back garden undeveloped, so the proposed Garage is a permitted development.
Example 2: Needs planning permission
The back garden is still 100m², but your proposed Garage is 45m², plus you’ve already for a shed that’s 5m², and a greenhouse that’s 10m². This means 60% of your back garden is developed, and you’ll likely need planning permission for your wooden Garage.
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What is Building Control?
You’ve used our checklist and worked out that your Garage will be a permitted development. But does this mean that your Garage can be as big as you like? Not quite.
Even if your Garage is within permitted development, once it’s over 30m², you’re governed by Building Control rules. Building Control ensures your wooden Garage meets Scotland-wide standards for construction quality, safety and sustainability. If your Garage is over 30m², you must have a building warrant before work can begin.
Going through Building Control increases the overall cost and duration of your timber Garage project. To obtain a Building Warrant, you often need to hire an architect and a structural engineer to prepare the application. There are also fees for the application itself, which are decided by the overall value of your project. The additional costs for the architect, structural engineer and application can be anywhere from £5000 to £12,000.
This is why we don’t construct many wooden Garages over 30m². The additional fees needed for a Building Control approved Garage often push the project out of scope for the customer.
How does the Building Control process work?
Building Control can be a bit difficult to wrap your head around, so here’s a breakdown of the full process:
Preparing the application
You’ll need to hire an architect and, in some cases, a structural engineer. They will create the plans and drawings for the application. This is also a good time to get in touch with the manufacturer who’s building your Garage. Their specifications and manufacturing processes should be included in the proposed plans.
Submitting the application
The building warrant application is submitted to your local council through the online building applications portal. The application should include your proposed plans and drawings for the Garage, and the appropriate application fee. If you’re unsure what to include in the application, your local council can provide guidance.
Your application is assessed by your local authority to ensure your proposed Garage meets Scotland-wide Building Standards. They aim to have an outcome to your building warrant application within 20 days. But be aware that there can be delays, and timings tend to vary between local councils.
Receiving your building warrant
If your building warrant is granted, you’ll receive the warrant itself and the Construction Compliance and Notification Plan (CCNP). The CCNP informs you of any inspections planned during the construction of your building.
If your building warrant is rejected, your local authority has 10 days to inform you of the necessary changes. Then you need to go back to your architect and structural engineer to make the amendments. Then you need to submit the application until it’s approved.
Garage construction
When work starts on your timber Garage project, you need to inform your local council.
You need to stick to the exact plans laid out in the application. Otherwise, you need to apply for an amendment to your building warrant, which has an additional fee. This can delay your Garage project because you need to wait until the amendment has been approved before making any changes.
Submitting the completion certificate
Once your wooden Garage is finished, you need to submit your completion certificate to your local council. Your council might make any necessary inspections to confirm your Garage is the same as the proposed plans. Then they will accept or reject the certificate. If it’s rejected, they’ll tell you what changes need to be made before it can be accepted.
When the certificate is accepted, you can start using your new wooden Garage!
For more in-depth information about the Building Control process, have a look at the Building Control customer journey.
Will G&M build a wooden Garage over 30m²?
Our wooden Garages are Building Control-compliant. This means that the methods and materials we use are in line with Building Control standards. So, we definitely can build you a Garage bigger than 30m²; however, there are some conditions.
When you come to us for a project that needs a building warrant, such as a wooden Garage over 30m², we’ll engage our architect and structural engineer, who will put together the application for you. We work with these parties often, so they know our exact specifications and what needs to be included in the application. Then we’ll submit the Building Control application for you.
If you’d like G&M to build you a Garage that needs a building warrant, we always recommend that you come to us first, before engaging your own architect and structural engineer.
Here’s why:
If a customer hires an architect and a structural engineer to draw up the plans for their building warrant application, they’ll include a generic timber garage specification. Then, when the building warrant gets approved, the customer gets in touch with us and asks us to build them a Garage to match these plans.
The issue with this is that it requires us to alter our specifications and manufacturing process. This is time-consuming and increases project costs significantly, often to the point where the building becomes out of the customer’s budget.
What’s the biggest G&M Garage I can have?
If you’re happy to go through Building Control, then you can pretty much have a Garage as big as you’ve got space for – remember, if you’re going to take up more than half of your back garden with any existing developments, then you will need planning permission.
The biggest size that we’ll build a wooden Garage to is capped at about 70m². Any bigger than this would likely be better suited to a construction company to build onsite, rather than us manufacturing it in our workshop.
What do we recommend for Garage projects over 30m²?
When you come to G&M for a wooden Garage over 30m², the first thing we’ll recommend to you is splitting up your space into more than one Garage building. As long as you keep each building under 30m², then you can have the area you need, without the hassle of going through Building Control.
Here’s an example of a previous wooden Garage project:
The customer originally came to us looking for a massive 70m² timber Garage. The Garage itself was going to cost around £90,000, and including all the fees associated with Building Control, would have been closer to £100,000 for the full project.
Instead, Cara suggested splitting up the space into three individual buildings. The result was 3 Apex Garages and a carport, giving the customer over 90m² of usable space.
- 6m x 5m Apex Garage with a 6m x 3m Carport
- 6m x 4m Apex Garage
- 6m x 3.6m Apex Garage
This gave the customer all the dedicated space they needed without the expense of Building Control. The overall project ended up costing around £61,000 for the three separate garages – a fraction of the originally proposed Garage.
What’s the biggest single-skinned wooden Garage I can have?
At G&M, we build our wooden Garages to our unique 3-Tier specification, which includes a layered wall and an air cavity. This keeps our Garages completely watertight. Our construction methods mean our Garages are very sturdy. This allows us to build them to large sizes without structural issues or any moisture ingress.
This isn’t the case for all timber garages on the market, though. The majority of wooden Garages are single-skinned buildings, which means one layer of wood makes up their walls (like a big shed).
The bigger the timber building, the more issues you’ll have with water ingress – especially in Scotland. That’s why we don’t build our Sheds, which are single-skinned, in sizes bigger than 12’ x 10’.
From our experience of putting up timber buildings in Scotland for over 30 years, we have found that a single-skinned timber building any bigger than this will have problems with timber movement and water ingress.
So, even though you can buy a 45m² wooden Garage relatively cheaply from a timber buildings supplier, it doesn’t mean that it’s a wise investment. Especially with a large timber building in Scotland, the way it’s constructed is going to play a huge role in how it performs and how long it lasts.
If you’re planning to have a single-skinned Garage larger than 30m², something to keep in mind is that Building Control emphasises that the owner of the Garage is responsible for the work. This reinforces the importance of choosing a reputable construction company or trades worker to carry out the Garage works.
What’s the biggest wooden Garage I can have?
Now you know that the biggest wooden Garage you can have depends on both permitted development and Building Control regulations. Any Garage over 30m² needs to go through Building Control in Scotland, but this doesn’t mean you can’t have the big wooden Garage of your dreams.
G&M can help you bring your project to life, designing a Garage that works for your space, your budget, and your needs. Book a Consultation to chat with our Team about your big Garage plans today.
If you’d like to get a better idea of Garage sizes in person, visit our Show Area, where we have a 6m x 4m Close Board & Strap Garage and another 6m x 4m Garage with a carport attached, for you to explore.
