
(Under 12m2) Specification
This article is about our former summerhouse specification, which has since been replaced by our brand-new Garden Rooms (under 12m2). It's worthwhile reading, but to jump straight to learning more about the new spec, click on!
Right folks, you’re in the market for a garden space to spend #ShedLoads of time in. That’s fantastic stuff, and you’ve come to the right place. But there’s one thing bugging you. You just cannot decide if you want a Garden Room or a Summerhouse.
We know that you’re wondering about loads of things…
What is a Summerhouse?
What is a Garden Room?
How can each of them be used?
What is actually the difference between a Summerhouse and a Garden Room?
All completely valid questions, folks. Initially, it does seem difficult to make key distinctions between these two types of buildings.
However, bear with us today and we’ll walk you through EVERYTHING that separates a summerhouse from a garden room.
What is a Summerhouse and its uses?
A summerhouse is traditionally a seasonal building or shelter used for relaxation in warm weather. |
A summerhouse is a place to relax, crack open a book and have a drink of wine. Feet up, pillows plumped, sun blazing through the windows: life is good.
Your summerhouse is there to enjoy, either by yourself or with friends and family. The PERFECT time to use it is summer, but that’s not to say you can’t use it in spring or autumn. However, your summerhouse isn’t designed for 24/7, 365 days a year use. As the definition says, it’s a place to relax. And most of us can’t relax all day, every day.
Your Summerhouse is mainly a space to unwind and escape the stresses of life.
Warm weather is when your Summerhouse is at its happiest. There’s nothing it loves more than warm air seeping through the timber with the doors and windows open.

As you can see, summerhouses are built with a single skin. So in summer, they are ROASTING hot but pretty chilly when cold. After all, the only thing that separates you when the outdoors is 19mm Scandinavian Redwood; it can only keep you so cosy.
What is a Garden Room and its uses?
You can spend all the time you like in a Garden Room. Whether it’s for work, rest, or play, the Garden Room does it all.
Home Offices, Gyms, Games Rooms. We’ve seen it all. They’re amazing buildings and completely transformative to your garden, and your home.
These buildings are ready for use 365 days a year, and that’s no joke. Whether you choose from our Under 12m2 range or our custom Blackstone Garden Rooms, you’re all set whatever the weather. It doesn’t matter if you’re working the 9-5 in January or you have the family round for dinner in July. Garden rooms are built to make it all possible.

Hot in the Winter, cool in the Summer. It’s got it all. ✅
What makes Garden Rooms and Summerhouses different?
Right! Now you know what they can both be used for. Now let’s look at the difference between summerhouses and Garden Rooms in detail.
Summerhouse vs Garden Room: U12m² Garden Rooms
Let’s kick off with the Garden Rooms.
As the name suggests, our Under 12m2 Garden Rooms are, well, under 12m2! The smallest of these buildings is 2.4m x 2.4m, and the largest is 3.6m x 3m.
They’re absolutely perfect for transforming a corner of your garden into a hobby room, a space to relax, or somewhere to sneakily watch the football when Strictly’s on the big telly.
These buildings offer the relaxation potential of a summerhouse but with year-round access. Maybe you can relax all day, every day!
Or if you’d like to combine working from home with seeing the sky every now and again, Garden Rooms make perfect garden offices.
These smaller buildings have a unique three-layered construction, and feature low-maintenance Radiata Pine ThermoWood cladding.
Summerhouse vs Garden Room: Blackstone Garden Rooms
If you’re looking for something bigger than 12m2, our Blackstone Garden Rooms fit the bill!
These larger buildings are custom-built projects which are tailored to meet your needs.


Yep folks, the Garden Rooms can basically be anything.
Blackstone Garden Rooms have five-layered walls, making them fully compliant with Building Control. In other words, they function in the same way as your house does, and they’re just as safe and stable.
Effectively, they are built exactly to the size that you need them. It’s much more of a case of you designing the Room with us, as opposed to getting a standard design and size as per the U12m2 Garden Rooms. Whatever your Blackstone Garden Room dream is, we’ll do our best to make it happen.
Let’s move on to Summerhouses.
Summerhouse vs Garden Room: Summerhouses
Summerhouses can be as small as 2m2 and go all the way up to around 12m2
Summerhouses are generally sold in standard designs and sizes. This is reflected in both style and cost. However, if you buy from a manufacturer they may offer custom sizes and designs to best suit your needs.
The crucial thing to know about summerhouses is that they are single-skinned buildings. They have a single layer of timber that forms their walls and roof, and this single layer is all that stands between you and the elements.
Single-skinned timber buildings aren’t suitable for year-round use. Apart from the temperature, in the wetter months (which sometimes includes all twelve!) they are susceptible to water ingress.
This doesn’t mean that water will come pouring through your summerhouse walls. If it’s a well-built affair with a good specification, a summerhouse should keep water out most of the time. However, it’s important to understand the limitations of a single-skinned building.
How Much Maintenance Does A Summerhouse Need?
Something else to consider is how much maintenance you’ll have to carry out. If you’re happy to paint your summerhouse carefully every few years, air the buildings regularly and inspect it for any signs of water ingress, you’ll be just fine.
These jobs are not negotiable, however. If you use your summerhouse in June, July and August, then close the doors and forget about the building until the following year, you might find it difficult to get the doors open again!
Paint helps minimise water ingress, and protects the timber, extending the life of the building. If you don’t stay on top of this job, you’re inviting mould and rot into your summerhouse.
If you put in the work to maintain a timber summerhouse, a good-quality building should last for thirty years or more. But remember – a single-skinned summerhouse won’t perform the same way as a Garden Room. This is reflected in the cost of the buildings.
Summerhouse vs Garden Room – is there a difference in Planning Permission requirements?
Ah, that old chestnut. Planning permission is something you need to think about regardless of whether you’re installing a summerhouse or Garden Room.
Now, you may think that due to the size of the Garden Rooms, you’re more likely to need planning permission, but it isn’t really the case. Planning states that, as long as the building is under 30m², then it is not necessary.
Furthermore, both summerhouses and Garden Rooms largely avoid planning if placed outside 1m of a boundary. If you want to place it closer than that, then some summerhouses can get away with it; Garden Rooms… not so much. There’s a lot to it, so I’d really recommend reading some content we’ve produced on exactly this to get a better grasp of what to expect for the different types of builds.
I’m not trying to get out of writing about Planning (but equally, could you blame me?), but the topic is just so vast that it needs its own article. As long as you:
- Ensure the build is under 30m²
- Ensure that it is placed outside 1m of a boundary – and if it is not – ensure that all material within that 1m is under 2.5m in height
then half the fight is already done. Articles attached here, folks:
- Garden Rooms: Do I need Planning Permission and/or Building Control
- Summerhouse Buyer’s Prep – Planning Permission
Summerhouse vs Garden Room: is there a difference in cost?
OK, costs, yes. Another very considerable difference.
At this point, it’s important to reiterate that summerhouses are single-skinned, and have single-glazed windows. In comparison, garden rooms are fully lined, insulated, and have double-glazed aluminium or uPVC units.
For that reason, the cost difference issssss…. large!
So, a good solid summerhouse, like the ones produced by Balmuir Sheds in Dundee, costs around £2500 for an 8′ x 8′ building, and £4000 for a 10′ x 12′ building.
You can buy much cheaper summerhouses, of course, but if you want a good-quality building, use our Summerhouse Buyer’s Checklist. This helps you make sure you’re buying a sturdy addition to your garden that will stand the test of time. Otherwise, you could be replacing the building sooner than you think.

In terms of Garden Rooms, however, our U12m2 buildings range from around £9000 to around £14,000. Blackstone Garden Rooms start around £18,000 and can be upwards of £60,000. It all depends on the size, and how you choose to modify the design.
Check out some of the garden rooms we’ve done in our Garden Room Brochure
Do I want a Garden Room or a Summerhouse?
Well, folks, this has covered pretty much everything that separates a Summerhouse compared to a Garden Room. If you’re looking for all-year-round use, then the Garden Room is the one for you.
However, if your budget is under £9,000 then you’re realistically looking at a summerhouse. If you want a seasonal building to enjoy when the weather is warm, this is exactly what you’re after. Remember that a summerhouse needs maintenance, especially if you want a long-lasting building.
If you think, having read this article, that either of our Garden Room ranges is what you’re looking for, please book in to speak to one of our Sales Consultants here: Book Appointment – Gillies & Mackay
Still not quite ready to book an appointment yet? Download our brochures here to get an even more detailed flavour of what’s what. Download Our Price Lists – Gillies & Mackay