Building a double garage with office/annex above

[sidekickdmr]

In the process of buying a house and waiting to exchange till I get too excited but within the grounds of the house we are Planning to build a double garage.

We would like to put some accomadation above, would like to put a basic studio granny annex so a small kitchen, basic bathroom and lounge/bedroom. we would be using it as a mancave/office in the meantime but may put a relivive/friend in there at some point for a little extra income.

The building will be on the boundry line but there are no neghibours will be against open forest/pasture land.

As far as overlooking goes I was thinking Velux windows in the roof so no issues there.

And it would have a seperate external door next to the garage door with internal staircase.

a bit like this but red brick to match the house

[Chapmanesque]

Yes, they work well.

I was largely responsible for introducing them on a lot of the new builds we did at the last big housebuilder I worked for: I coined the term HoG for them - Home Office Garage; as distinct from FoG, which is a Flat Over Garage (AKA 'coach house') in developer-speak.

I now work for a timber frame manufacturer and we have a range of similar designs available.



Edited to add:

You'll probably find that to create enough space in the roof for the facilities you're after, you may need to lift the eaves a bit to make it a half-storey rather than just a roof space, though.

Here's one I did earlier:




...and if you do lift the eaves a bit, it's a good idea to think about using more than one material (as per the drawings above, which used cedar boarding over brickwork), as they can look a bit top-heavy if you do them in brickwork alone. All timber cladding (or better still, a traditional timber frame) or all render is not so bad, but brickwork alone looks a bit heavy.

Good information (and a picture of what the space inside can look like) here:

http://www.beamlockbuilding.co.uk/garage-with-room...

Contact me via my profile if you want further advice.

Edited by Chapmanesque on Saturday 22 February 13:39

[Chapmanesque]

Oh... and just to further add: you'll need to be careful about the staircase arrangement, even if you do lift the eaves, in order to ensure sufficient headroom at the top (you need a minimum of 2 metres above the pitch line of the stair). You'll notice that the stair on the plans above has a winder at the top, so that you don't end up in one corner with 3'0" headroom on the landing!

But that's something that whoever draws up your plans ought to attend to.

Edited by Chapmanesque on Saturday 22 February 20:31

[E31Shrew]

We built one at our previous house and put the iron staircase outside. Gave us a bit more room

[sidekickdmr]

Thanks for the help guys, really appreciate the information chapman

And E31 I have thought about that but just seems a little "un homely" to walk up external metal/wood stairs

[Chapmanesque]

E31Shrew said:

We built one at our previous house and put the iron staircase outside. Gave us a bit more room

Yep, we usually put external stairs on our timber framed jobs, too. More flexible as you say: you don't need the clear landing at the bottom (ie. the bottom riser can line through with the front of the building, or even project a bit in front of it), and you can even use L- or U- shaped stairs with a quarter or half landing, if you want.

Even so, I think you'll probably need to lift the eaves to get enough space for what you want, up there, but if you don't lift the eaves, you'll find that the upper landing has to be pretty much central on the gable to get sufficient headroom as you enter the room over the garage.

[rfisher]

How much would this cost?
I've got a detached double garage with a couple of meters open space on 1 side.
Would be fairly easy to build out to the side and up.
Eaves would need to be raised.
Foundations are solid concrete by the look of it but not sure how deep.

[E31Shrew]

sidekickdmr said:

Thanks for the help guys, really appreciate the information chapman

And E31 I have thought about that but just seems a little "un homely" to walk up external metal/wood stairs

Just meant that the internal ground floor wasn't compromised with a set of stairs. Plus there was no need to ever go from the bedroom/office upstairs, straight in to the garage.

We had a bar set up downstairs plus a sauna on one side and on the other was racking and car space. Under the external stairs we boarded up , popped a door on and this became push bike / lawn mower storage.

Upstairs was a small bathroom with loo , sink and shower. In the main room was a small open kitchen plus the bedroom. A great set up which is sorely missed!

[Chapmanesque]

rfisher said:

How much would this cost?
I've got a detached double garage with a couple of meters open space on 1 side.
Would be fairly easy to build out to the side and up.
Eaves would need to be raised.
Foundations are solid concrete by the look of it but not sure how deep.

If it's a normal 'developer' double garage (single skin of brickwork with local thickening to form piers) then the problem is that it's structurally pretty marginal already, so you can't just go and plonk another half storey and a loadbearing floor on top of it... you might as well demolish and start again, for all the good the existing structure will do you. You'll notice that the drawings above show a full cavity wall thickness for the external wall.

To build from scratch will obviously depend on the specification of what you want to put up there (especially if you're getting into kitchenette and shower room facilities, etc.), what materials you're using and how you're going to go about building it (ie. with you laying you own bricks and concrete at one end of the spectrum and a turnkey build from a contractor at the other), but say £15-£20K for a fairly basic turnkey package.

[GoneBananas]

I built one of these just before Christmas, cost was about £40k all in.

[New POD]

GoneBananas said:

I built one of these just before Christmas, cost was about £40k all in.

fking hell. My dream home.

[zuf]

My garage is 6m sq with a room above accessed via an external stair case ...... Home office type thing with power & heating .... We use it for our gym equipment .....

Pitched roof is gabled one end and hipped the other so could have a bigger useable floor area if both ends were gabled but I think you will struggle to get a kitchen/shower & living/bed space .... More like a shower/wc with the rest open plan .....

Great extra space though!

Cheers
zuf

[sidekickdmr]

Yes I am happy for it to be a studio setup with a basic kitchen open plan within the lounge/bedroom.

So basically one big open plan room with a separate "pod" for the shower room/WC.

In relation to the stairs, they wouldn’t go into the garage. A proper external front door next to the garage door with contained stairs going straight up into roof space. A bit like a coach house would have.

and good idea RE: the gabled ends, not really thought about that before, would make the use much more useable.

Any architects that anyone can recommend for the project? keen to get the ball rolling.

[Bill]

We've got plans to do this to our 5x8m barn. As the site slopes we're hoping to go down a metre and lose a little of the current 2.6m internal height to get a decent amount of headroom inside. Our plan is to glaze both gable ends, with a Juliet balcony at the bedroom/north end and the stairs/big folding doors at the living/south end.

I've got a pre-application meeting next week...

[sagarich]

GoneBananas said:

I built one of these just before Christmas, cost was about £40k all in.

Wow!

[B17NNS]

GoneBananas said:

I built one of these just before Christmas, cost was about £40k all in.

That's lovely. When you say 'one of these' do you mean as in a kit?

[MagicalTrevor]

GoneBananas said:

I built one of these just before Christmas, cost was about £40k all in.

Nice, any more photos (photo album/build thread/blog)?

[GoneBananas]

B17NNS said:

When you say 'one of these' do you mean as in a kit?

Yes, I used a local timber frame company here in Essex, I designed what I wanted and they did the drawings which I used to apply for planning, I negotiated free plans as I bought their frame.

The Ground works/ brickwork cost £8k
The frame cost £15K
Oak Cladding £5
Windows £2k
Garage doors £500 materials (I made them myself)
Roof was £7k (I had the slates already from dismantling an old building on site).
Stairs £500

I still have to plumb and electric 1st&2dn fix + insulate and dry line. + buy a car.

[GoneBananas]

btw, thanks for the kind comments.

another photo.

[GoneBananas]

Cladding and roof