Converting garage

[anawanahuanana]

Hi there. We are currently toying with the idea of converting 1 half of our double garage into a bedroom and laundry, and leaving the other half as a single garage/workshop. Firstly, apart from the obvious work of moving the water supply into the garage, and putting in a floor waste, plus electrics in the new room, is putting up the internal walls something you can legally do yourself? I think it should be seeing as there is no structural alterations. Also, do you think it would put people off buying the house in the future? Is a double garage seen as more desirable than an 4th bedroom in general? What do you do with the garage door on that side? Try and match up bricks and fill it in, or sliding tinted doors? Not definately going to do it yet, but rapidly running out of room in the house, and apart from that we love everything else about the place. We'd put up a double carport for the cars outside, and this option initially looks alot cheaper than building up. By the way, its a brick veneer lowset.
Thanks in advance.

[silentC]

You can put the internal walls up yourself but you need to get development approval to do it because you are creating a habitable room within the house.

This used to be a very common thing to do. There are a lot of houses around here that have sliding glass doors on the ground floor opening out onto the driveway that are suspiciously similar in size to a single garage door. One that I know of had a carport added to the front of the house so that the garage wasn't missed.

I don't know what is more valuable: a LUG or a 4th bedroom. When I was building an extension that would close off access to the freestanding garage at the rear of my house in Sydney, I rang the real estate agent I bought it from and asked her opinion. She said don't do it, people value having vehicle access to their backyards. I did it anyway and we sold the place for double what we paid for it 5 years earlier. Maybe if I hadn't done it we would have gotten more. I don't think so.

The other thing to keep in mind is that if the walls are not lined, lining them might introduce problems with termites. In another case I know off where a room was built under a house, the framing provided the termites with direct access to the sub floor of the house above because it bypassed all the ant capping. Just be aware of that if you go ahead - you might give termites access to your roof.

[anawanahuanana]

Thanks for your reply. The garage internal walls are already lined, and the house has a Cypress pine frame, so as long as I make the new internal walls from the same, I hope termites wouldn't be an issue. I've seen a few houses the same, with the sliding door in place of a garage door, and I never really considered it an option before. But it pains me to think of moving just to gain an extra room. I guess still keeping a single garage should keep some prospective buyers happy, and also myself when I have to do some work on the car!
Thanks again. I await further opinions.................

[HappyHammer]

You must be the only person on this board reducing the space available for his workshop

HH.

[Wongo]

A bedroom next to the workshop! Sounds like a heaven to me. I like the idea.

[No dear, I mean I don’t want to come in last at night to disturb you and the children ]

[joe greiner]

Similar to silentC's remark, lots of them like that here too. But I've never seen one done for only half the garage. Oz building codes may be different, but here a garage must have fire separation from the main dwelling; generally extra gyprock or such. That would apply to your new wall.

Joe

[silentC]

Oz building codes may be different

They do differ on that point. You need a firewall between seperate dwellings, such as flats or attached dual occupancy, but not between a garage and the living areas of the associated dwelling.

At least that was the case a couple of years ago. The only major change I'm aware of recently was the introduction of BASIX. That might also affect this scenario because I believe you are required to bring the rest of the building up to current standards if you do any work of a certain size to an existing dwelling. This includes things like energy efficiency (insulation, thermal glazing etc), water conservation and smoke detectors amongst others.

The majority of the conversions I have seen around town were done years ago and I doubt that there was any development approval at the time. About 10 years ago the local council declared an amnesty on unapproved granny flats (many of which were built this way) and so a lot of them are now approved. They did that as the new legislation was brought in and it's a lot tougher now. If you go ahead and do it without approval, they can make you rip it out and when you come to sell, it will be noted by the council inspection and you may be required to either demolish it or get it approved before the sale can go ahead.

[anawanahuanana]

Thanks to everyone for their input. The Basix thing is a bit of a concern for me, but now SWMBO is having serious second thoughts about the whole thing! She now says it's all of the garage (ie: No workshop at all) or nothing..... Sounds like nothing may be the answer for now, but you know how often the female of the species change their minds. Watch this space..........

[LegacyGT]

my grandparents have a house with this "extension" done. Its livable. Extremely hot compared to the rest of the house - but that can be fixed.

The garage door was converted to a window. Mustve ben tricky too coz its one of those archway type cresent type garages openings.

i say go for it.

[ausdesign]

Usually a big stumbling block is the requirement to have an 'impervious membrane' under the concrete if it's to be a habitable room.

[echnidna]

Usually a big stumbling block is the requirement to have an 'impervious membrane' under the concrete if it's to be a habitable room.

Would a plastic membrane on top of the concrete overlaind with battens & timber flooring satify that requirement?

[ausdesign]

I'm not sure on that Bob off the top of my head. Logically if you were building a timber floor over a concrete base you wouldn't but then minimum subfloor clearance & ventillation would [could] come into play.
The tendancy for moisture to be drawn up to the warmer side of the concrete could be a problem & the plastic laid on top should prevent that but truthfully I'm not sure.
In the past we've designed with a plastic membrane laid over the concrete & then another floor poured on top incorporating a rebate around the perimeter with a timber frame built to create a cavity - ending up with a 'brick veneer type construction.
This then meets the requirements rather than having to seal the outside brickwork [ which is another problem to consider] to stop water penetration through the single skin.
All this is dependant on sufficient head height.

[Terrian]

Usually a big stumbling block is the requirement to have an 'impervious membrane' under the concrete if it's to be a habitable room.

I wonder, does having a 12" - 18" thick, 32mpa, concrete garage floor count ?
(hey, I got a real good deal on the concrete )

[ausdesign]

Generally if the house is on a slab & the garage is poured as part of the main slab then a membrane would be in place.
If the garage has been poured as an 'infill' slab then the chances are good that there is no plastic.
Thickness or strength of the concrete wouldn't come into the equation.