However much you enjoy working on cars (or even
just working with your hands), if you have no facilities in which to do it, life
is hard. Sure in a mild climate - like that existing is most parts of Australia
- you can work under an open-sided carport; I’ve even seen people doing major
jobs like engine swaps on the road outside their house. But for convenience,
security, safety and weatherproofness, a decent workshop is a must.
For the last eight years, I’ve worked beneath my
house (the house is elevated) in an open-sided, concrete floor area. There have
been three major problems with this: there is little security from theft; in
wet, windy conditions moisture blows right through the workshop; and the limited
height makes things squeezy for storage. The floor area is also smaller than
desirable. (In the mild climate of SE Queensland, the lack of heating and
cooling haven’t been problems.)
So I’ve decided to bite the bullet and build a
Size, Shape and Construction
The first decisions that need to be made are size
Here in Australia, the cheapest workshops to have
built are sheds made from galvanised sheet steel. Normally called ‘garages’, a
typical one is a “double garage” – 6 x 6 metres with a wall height of 2.3 metres
and a shallow pitched A-shaped roof. Because they are produced in large
quantities, the pre-cut materials are cheap, the erection is straightforward and
the cost of putting in a concrete slab floor is kept well under control. Council (or planning)
approval will also normally cause no problems.
However, while - as the name suggests – it’s big
enough to park two cars inside, a double garage is actually pretty small. For
example, if you want to work on your car in your workshop, a double garage is
the absolute minimum space you need. The car will fit in the middle (but might
need some pretty good manoeuvring to get it there!) and then you can work around
it. But if you have a workbench, some machine tools and plenty of storage
shelving, things start to get tight.
Of course, if the 6 x 6 metre shed is going to
house just your tools, storage shelves and workbench, things get lots
better! If you live in a mild climate, you might consider a 6 x 6 metre garage
fronted by an open-sided carport – or even a large paved or concreted area
covered perhaps with shade cloth sails. There you have a safe place to put a car
up on stands, pull out suspension, etc, while the garage is used to do fine work
and operate bench tools like a drill press.
If you’re on a very tight budget for money or
space, you can take the above approach but use a single garage for your bench
and tools, with the car parked in front of the shed, again on a hard
However, it’s a lot better to budget for a
double “double garage” – in other words, a 12 x 6 metre shed. It sounds
huge, but it lets you park a car in the shed, have plenty of space to work
around it (including for panel work) and have space for a proper
workbench, machine tools and storage shelves. For major work, like restoring a
car, this size of workshop will make an enormous difference to how quickly jobs
will be done – and how well they’ll be done. If the workshop also has to do duty
at times for car storage, you’ll also be able to organise a shed of this size so
that two cars can be parked at one end when work isn’t being done on a car.
Like a 6 x 6 metre shed, a 12 x 6 metre shed is a
standard size and so is commonly available. The metalwork is likely to be a
little less than double the price of a 6 x 6 metre shed but note that other major costs
like the concrete floor and required earthworks will in fact still be double the
6 x 6 metre shed. A 12 x 6 typically has four doors arranged along one side, or
two doors located at one end.
If you want to make the most of the available
space, consider having a non-standard size shed erected. Some shed manufacturers
and agents have computer software that allows them to quickly and cheaply design
sheds to pretty well any width and length.
For example, I have decided I want a 14 x 6 metre
shed – 2 metres longer than ‘standard’. That might sound a trivial change, but
the extra length is sufficient to have, for example, a bench across the full
rear wall of the shed – and have room to work in front of it! When you put it
that way, the gain is obvious.
A wall height of 2.3 metres is standard – but
again many shed suppliers will allow you to specify a higher wall.
A workshop with higher walls has some major
Foremost is the extra storage space that is
created – even in a 6 x 6 metre shed (with one wall taken up by two roller
doors), an extra metre in height gives you 18 square metres of extra wall
storage space! Another advantage is that a higher shed allows you to install a
hoist – however, a hoist is an extravagance for most people with home workshops.
A shed with a high roof is more easily illuminated as very powerful industrial
lights can be placed high up, spreading the light broadly and evenly. Finally,
going higher does not increase the cost of the concrete floor and earthworks,
and often has a minimal affect on the erection cost.
When specifying a shed also consider:
Ventilation (eg rotating wind-driven ventilators,
Insulation (eg foil insulation placed under the
roofing sheets during construction)
Natural lighting (translucent roof panels,
Presence or otherwise of a personal access
Required wind rating for the
Many people will have few options for where a
workshop of the desired size can be placed. But before getting too carried away
with mental pictures of where it will be, talk to your local council (or
relevant planning authority).
Aspects that may be dictated by the authority
include the minimum distance the shed is from the road, from boundaries, and
from existing dwellings. There may be pipes, cables or easements over which the
shed cannot be placed. Your neighbours may have a right to object if it blocks
their view or shades them. There may be maximum floor areas and wall heights,
and the shed may need to be coloured.
You’ll want easy car access to the workshop – not
only for working on a car but also so you can move goods into the shed and also
have the floor concreted without requiring the service of an expensive
Almost certainly the area where the workshop is to
be placed will require some earthmoving. At minimum the area should be cleared
of grass and other vegetation; at maximum, major earthworks including retaining
walls may need to be built.
I live on a steeply sloping block, so the location
of the shed was always going to be problematic. My initial location required no
less than a 3-metre high retaining wall and plenty of fill. That didn’t worry me
much – until I got my first quote for earthworks.
“The wall will need civil engineering,” said the
earthworks man. “And I don’t see much change out of six grand
Since the total budget for the workshop is
$20,000, that had me gulping. So I mentally moved the shed forward six metres.
This required installing a new driveway entrance and still-substantial
earthworks. The bill was going to be similar.
I then radically revised the workshop’s
provisional location. In the new location the required earthworks consisted of a
cut and fill – that is, scooping out part of slope and building it up at the
lower level to form a flat pad. Also required was a 20 metre long, 1 metre high
I then realised that in order that really good
access could be gained (access that would allow a concrete truck to back in, and
that would allow me to easily move my machinery into the workshop), I’d need to
have the driveway widened. This involved laying a storm water pipe and then
having compacted fill placed on top.
The total bill for earthworks was about $5000.
Unlike the last large shed I had built in another
Australian state, it is normal practice in Queensland for the concrete slab to
be poured first and then the shed built on top of it. That means that the
concrete slab forms the full foundation for the shed. (It also means that the
slab must be dimensionally accurate.)
On my site, with half the shed on fill, the slab
needed piers cast into place to support the area of concrete that’s been
built-up. These piers needed to go down to the natural soil level.
This all seems straightforward, but it is not.
Firstly, the local council must approve the plans for both the shed and the
concrete slab. These plans are provided by the shed seller, but – as I found out
– the plans are predicated on the site being flat and level, and not having any
built-up areas of soil fill. When asked what changes the shed vendor would make
to the concrete plans to make the slab suitable for my location, the shed guy
just shrugged and said: “I’m not a concrete engineer!”
So then I got concreters in to look at the site.
They suggested that more piers be used than had been deemed necessary by the
shed vendor, and that furthermore, the piers on two sides of the shed be
linked by a long L-shaped concrete beam cast into place.
Quotes for this work varied from around $6000 -
$7000; I settled on one at $6950 – knocked down to $6500.
I then started chasing final quotes for a 14 x 6 x
3 metre shed, complete with two roller doors in one end, two translucent roof
panels and two spinning ventilators. The walls were to be in Colourbond and the
roof in natural galvanised finish. The quotes were for supply and errection.
I found the whole process an eye-opener –
primarily because the quotes varied so much. At the bottom end was a quote for
$10,800 and at the top end, one for $14,600! I got the quotes by simply dropping
off a specifications list for the shed and then asking that each company email
As it happened, I was back in the area of the
$14,600 vendor the next day and I decided to visit. I wandered in and asked in a
completely neutral tone if he could show me the features of his shed that made
it worth 35 per cent more than one of his opposition.
I actually thought he might be able to show me
better quality construction, higher grade steel, etc – but instead he simply got
out the quote and said: “Hmm, perhaps I made some mistakes!”
And he did find ‘mistakes’ – enough to immediately
pull the quote down by nearly $3000! What a scam...
In the end I settled on the cheapest quote, asked
for a few design changes (bolting the main beams, rather than tek screwing them,
for example), got another $300 knocked off the price and agreed to buy it at
$10,500, including errection. Note that this shed manufacturer uses the same
Bluescope steel, meets the same legal requirements and has a similar warranty as
the most expensive shed maker....
If you’ve been keeping count, you’ll have seen
that the cost of earthworks and the concrete slab will make up about half the price
of the whole construction. Even on ground requiring minimal earthworks, the slab
would still form a significant part of the overall cost.
However, the more I thought about it, the more I
realised the slab is really important. Not only will it have to support the
tools, machines and benches in the workshop, it also has to be rigid and strong
when vehicles are being jacked-up on it. It must also stay level and not sink as
any soil compacts over time. Finally, one day I’d like to build a car in this
workshop and that requires a smooth and level floor, providing a datum from
which to take measurements.
Think of it like this – the slab provides the
working surface and the rest of the shed just keeps out the weather!
Next: in detail - earthworks, concreting, materials delivery
Go here for the next in this series.
Interested in home workshop projects and techniques? You’re sure then to be interested in the Home Workshop Sourcebook, available now.