How Much Does It Cost to Build an Outbuilding?

What's the average cost of building an outbuilding?

The average cost of a concrete garage is £7220 to £9380 with the price rising to about £10,420 to £11,980 for a brick outbuilding garage.

As for a steam cabin, you’d need to set aside a budget of £2160 to £3820. Expect to pay around £6720 to £8380 for a small garden studio, or £7160 to £8820 to have a prefab wooden summer house built.

It would only cost about £775 to £925 to have a regular shed constructed.

outbuilding roof

What can determine the overall cost of an outbuilding?

The price of constructing an outbuilding can vary depending on factors such as the state of the work area, number of tradespeople hired, ease of access, and the location of the property.

The latter point is due to the fact that labour rates vary across the UK (as a result of differing living costs throughout the nation).

Many of the of the highest rates are found in the southeast (London in particular) and the lowest rates generally present in the north of England, Scotland, and Northern Ireland.

Outbuilding Prices

Here is a table showing the average prices of building different types of outbuilding:

Type of Outbuilding Total Cost
Concrete Garage £7720 to £9380
Brick Garage £10,420 to £11,980
Steam Cabin £2160 to £3820
Small Garden Studio £6720 to £8380
Prefab Wooden Summer House £7160 to £8820
Regular Shed £775 to £925
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What are the Supply Costs of an Outbuilding?

In this section, we’ll look at the material costs involved in constructing an outbuilding. This excludes the labour/construction cost.

As a result, these outbuilding prices would be especially relevant for a DIY build. Before delving into this, you’d need to conjure up some outbuilding ideas.

You should only undertake this work if you know exactly what is involved, from the practicality to safety to building regulations and more.

To have a concrete garage built on a fresh concrete foundation, the supply costs would land around £5200 to £5600. To build a garage with bricks would have a materials cost of about £7900 to £8200.

log store

Expect to supply costs to be about £900 to £1300 for a steam cabin, £4200 to £4600 for a small garden studio, or £5900 to £6300 for a prefab wooden summer house. For a garden shed it would land around £500 to £600.

The supply costs will account for roughly 50-80% of the overall costs with the labour expenses making up around 20-45%.

About 5% of costs will be attributable to waste removal. Supply costs will cover everything from the roof tiles to the outbuilding doors and their handles.

Supply Cost of an Outbuilding

Type of Outbuilding Supply Cost
Concrete Garage £5200 to £5600
Brick Garage £7900 to £8200
Steam Cabin £900 to £1300
Small Garden Studio £4200 to £4600
Prefab Wooden Summer House £5900 to £6300
Regular Shed £500 to £600

What are the Additional Costs of Outbuilding Construction?

There are a range of added expenses that you may incur when having an outbuilding constructed. Let’s take a closer look at some fairly common examples.

Minimum Fee

First and foremost, it’s possible that you’ll face a minimum fee. This might appear as an added cost to your bill. On the other hand, it may simply be a natural expansion of another expense.

For instance, if you are charged per day of labour, then even if the work lasts fifteen days and three hours or fifteen days and seven hours, you’d be charged for sixteen days of labour either way.

Size/Type of Outbuilding

The type and size of the outbuilding will be very important cost factors. For one, the larger the outbuilding, the higher the supply and labour costs would be.

Beyond that, with regards to type, this will shape the labour and material costs alike, in part due to the difficulty of constructing any given outbuilding based on its shape.


Of course the type of materials used will heavily shape the supply costs too. In addition, some materials are more difficult to work with, fit into place, etc. than others and this in turn could influence the duration of the project.

wooden outbuilding frame

This as a result would play a role in shaping the labour costs too. For example, the brick shed cost would come to more than for a timber shed.

Number of Tradespeople

The more people working on a project, the higher the labour costs per hour or per day would naturally be.

However, should this sufficiently speed up the project due to having more hands on deck, whether increasing the number of tradespeople on site would act as an added cost or a cost reduction overall would depend on factors such as how well the team of labourers work as a unit.


In the majority of cases, the longer the project lasts, the more it will cost. The only real exception would be if the entire project was billed based on a set fee agreed upon at the start.

Though, in most cases, a company/labourers will charge per day for a project like this or perhaps even on an hourly basis.

Tradesmen Costs for Outbuilding Construction

We’ll now discuss the labour costs of constructing an outbuilding. This section will also look at the various cost factors that can shape and alter the tradesmen cost.

On average, the daily labour cost will likely land around £170 to £190. This assumes a team of labourers on site to construct an outbuilding.

However, labour costs can reach up to about £1000 per day depending on the type of labourers hired among other factors. However, we’ll base our estimates on the average daily labour cost.

outbuilding frame

The labour costs would be about £2520 to £3780 to build a garage, whether made of concrete or bricks, £1260 to £2520 for a steam cabin, £2520 to £3780 to construct a small garden studio, or £1260 to £2520 if you intend to have a prefab wooden summer house put together.

As for a shed, the labour cost would land around £275 to £325. Among the most common factors that influence labour costs are the number of workers employed for the project, duration of the job, ease of access, the state of the work area, and whereabouts in the UK you are located.

How Long Does It Take to Build an Outbuilding?

We’ll now consider the durations involved in constructing an outbuilding. For this section, we’ll also look at the various time factors that may determine the length of such a project.

It takes about 14-21 days to build a garage, 7-14 days to construct a steam cabin, 14-21 days to put together a small garden office, and approximately 14-21 days to have a prefab wooden summer house constructed. As for building an average shed, this may only take one to two days.

roof timber frame

The primary time factors that influence how long it takes to build an outbuilding are the number of tradespeople hired, ease of access, the state of the work area, and potentially weather conditions.

Types of Outbuilding

In this section, we’ll look at the several types of outbuilding discussed in the costs sections of this article. When it comes to garden sheds, we’ll discuss both concrete and brick-built garages under the same sub-header.

Garage Outbuilding Cost

The most common type of outbuilding is a garage. In the majority of cases, a garage will be constructed at the side of a property. In other scenarios, it will be built as a standalone structure.

garage outbuilding

It may be made of materials such as concrete, bricks, or timber. Of course, garages are primarily used as a way to house vehicles, protecting them from the elements and the threat of theft.

Homeowners may also use a garage to store tools and other objects or simply for further utilisation alongside the rest of their house. The average cost of having a garage built is £7220 to £9380 if made of concrete or £10,420 to £11,980 if made with bricks.


  • Free parking space
  • Security
  • Protects your vehicles from the elements
  • Helps prevent winter issues with cars (e.g. ice on windscreen)


  • Can block off a side entrance
  • Uses up quite a bit off space
  • Can be expensive
  • Requires plenty of maintenance

Steam Cabin Cost

Another type of outbuilding that many homeowners choose to build is a basic sauna or steam cabin.

wooden cabin

An outdoor sauna/swimming pool sounds like a nice idea and has its benefits but considering that the UK sees the fifth highest levels of precipitation in Europe, having a roof over the sauna would be a worthy investment.

The average cost of having a steam cabin outbuilding constructed is £2160 to £3820.


  • Relaxing indoor environment that is separate from your home
  • Protects against the elements unlike a regular outdoor sauna


  • Can be costly

Small Garden Office Cost

A small garden outbuilding acts like a sort of mini shed but with a decorative and useful interior. Insulation is another key part of making a functioning garden office.

In today’s world, where remote work has become more the norm (and is set to remain more prevalent post-Covid than it was before the emergence of the pandemic in spring 2020), building a garden office makes more sense now than ever.

It may make sense to build such an outbuilding if there is insufficient space to utilise in your home for a new office space or simply to create a better sense of ‘a workplace’.

garden office outbuilding

Having a truly independent space to work may have many benefits for some, depending on their psychological and emotional needs.

For some people, using their bedroom or a spare room will suffice but for others who work remotely, they may need something more to keep their focus and motivation sustained.

It costs roughly £6720 to £8380 to have a small garden studio built.


  • Perfect for working from home
  • Separate space from main property


  • Expensive solution

Prefab Wooden Summer House Cost

The idea of a prefab timber summer house is to offer a more usable and appealing version of a shed.

wooden and glass summer house

Such constructions may come with windows and are often used for activities and downtime rather than simply as storage, although this too can be one of their functions.

You’d probably pay somewhere in the range of £7160 to £8820 for a prefab wooden summer house.


  • More appealing version of a shed
  • This wooden outbuilding can be useful
  • Separate from the main property


  • Can be fairly expensive

How Much Does It Cost to Remove an Outbuilding?

The average cost of having an outbuilding removed is anywhere from £500 to £2500. The cost will of course depend largely on the size and type of outbuilding as well as its shape and structural complexity.


The type of materials involved can also influence how much it would cost to remove as some materials are easier to remove/disassemble than others.


Q: What is classed as an outbuilding?

A: An outbuilding is a structure that is used separately from the main dwelling house and is not attached to the main property either.

Q: What size outbuilding can I build without planning permission?

A: A single storey outbuilding cannot have a height of more than 2.5 metres at the eaves and three metres overall with any roof barring a dual-pitched roof.

In the latter case, it can go up to four metres in height but no more. If the outbuilding comes within 2.5 metres of the boundary of the dwelling house’s cartilage, then it cannot be taller than 2.5 metres.

Q: What is an annex?

A: This is a relatively small independent living space. It may be used by the property owners in their spare time or to house another person as their own home.

Q: How much would it cost to construct a home observatory in my garden?

A: It would likely cost several thousand pounds in total.

Q: Will I need outbuilding planning permission?

A: Unless you surpass the height limits mentioned above or another limit of your outbuilding permitted development rights (e.g. you are planning to have an outbuilding constructed on the side of your property and you live on designated land), then you won’t need planning permission.

Full information can be found via the Planning Portal. Rules listed apply to England and Wales, thus they can differ from those applicable to Scotland and Northern Ireland.

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Author: Dean M

I have a Bachelor's Degree in Creative Digital Media, I'm a freelance writer and I've worked for clients such as the British Blockchain Association and I have experience in writing articles, YouTube video scripts, online guides and newsletters. I have written and produced many short films as well as a web series and feature film. I am also currently working on a novel.