Building A Granny Flat

I'm looking to build a granny flat for me to live in at my parents house for minimal money. There's currently a really old shed on the block with a concrete foundation that I'm going to build it on (6x4) and potentially add another 6x2 to one side to make it a little bigger. I've never really done my own building, but to cut costs I'm thinking I'd like to take a shot at doing much of the work myself. I've worked as a labourer on construction sites, and most of the basics seem relatively simple to get the hang of, which made me think doing it myself might be possible.

I have a few questions:

  1. What would you do yourself in terms of building, and what would you leave to professionals? (plumbing, electrical, asbestos removal etc).
  2. What are some good ways to keep costs low? I'd like to keep the slab and potentially the existing wooden shed frame and just build from that?

Comments

  • +2

    save your money move into the shed.

    • +1

      I would if it wasn't 70 years old and falling apart with asbestos walls. And completely filthy!

      • please remove yourself from ozbargain, that's no way of thinking.

        • +15

          Ozbargain isn't about living in filth! It's about living gloriously for less! ;)

        • +1

          @jakem742: I live in glorious filth, surrounded by cheap tat from Zapals and Gearbest.

  • +10

    First thing that came to mind was council approval for compliance.

  • +1

    yeah you'll need council approval before anything as it's gonna be a habitable space. you can either draw up the plans yourself or get a draftman to do it.

    if you've work on sites before, talk to some of the trades people, plumbers electricians and they'll give you some tips.

    • How detailed do plans need to be? I've just completed a civil engineering degree but don't really have the experience to do a fully detailed plan. If it's just something basic with dimensions I can probably whip something up!

      I don't really have a good idea of prices and whatnot though. How much / how long will it take to approve through council? I assume it would be easier given there is an existing shed in the same spot and it's really just a repurposing and renovation?

      • +2

        Guess again. A shed isn't a habitable building.

      • +1

        Firstly, there are two types of approvals you may need. A planning permit (that's the Vic name, aka development approval in NSW), and a building permit.

        In Victoria, councils are happy to meet with you before you start the process so you know what you'll need to submit in your application. Call the council and ask for a pre application meeting.

        If you can prove you are a dependent of your parents (that is, the person living in the granny flat is dependent on the people living in the main house), the flat can go up without a planning permit, so long a so long as it satisfies certain conditions. Once again, talk to council. Even if this is the case, you will still need building approval.

        • I'm considered independent now (23yrs) so don't know if that'd work. How do you prove dependance?

        • @jakem742: in vic last I looked it was more you needed facilities in the main house (ie laundry), rather than you needed assistance.

          I've had a quick look for "dependent persons unit vic" and it appears as long as the structure is moveable, they might not bother you.

          I would still call council and ask. Try and get as much information without giving your address otherwise they may flag that you're considering it.

  • Although, if memory serves, anything under 9m2 doesn't require approval… Even multiple 9m2 structures built in close proximity to each other.

    • This will be around 36m^2, so probs a little above that. :/

      • Height limits as well, IIRC over 2 metres (7 foot) needs approval.

        You can build a shed to put your mower in without approval, any more substantial need a permit. Mind you some councils don't give a stuff until the neighbours complain.

        • It's probably only about 7 foot high, tbh. At the back, it's only about 2.1m although the front is probs a little above that limit.

  • +1

    Or is it 4 * 9m2 structures with enclosed passages between them?

  • Where are you looking at doing this?

    • +1

      Hunter Valley, NSW. Why?

      • +7

        Reported.

        Joking :p

      • Local council rules vary. I think NSW is fairly easy to get approval of granny flats, but you'll still need to check local rules.

      • +1

        If it was SE QLD, I have a few contacts :)

  • Leave all plumbing, electrical and asbestos work to the pros. Doing your own plumbing and electrical connection is illegal, but you might be able to save some coin by workin with your plumber and electrician to dig trenches, run cable etc.

    • Yeah, I was only planning on running it out and getting everything ready for them to do the final connection. I didn't realise plumbing/wastewater was illegal! I just thought you would be stuck if it came to insurance?

  • +3

    Buy a used caravan and put it on site. Very common for people to do this to create another room

    • +2

      This buy a caravan for sleeping and if necessary bathroom, turn shed into a large open plan kitchen/lounge and gamesroom

      • We have a caravan but it's old and there's no cooling system so I would never be able to sleep in it during summer. Not a bad option in the cooler months though. :)

        The other problem is, I have nowhere to store my stuff in a caravan. I'd much rather give myself some space and turn this unused shed into a living area!

  • +2

    Is there a waterproof membrane under the slab? Pretty sure you need a waterproof membrane under a slab for a habitable building and without any you might run into problems.

    • The slab is 40-50 years old and I have no idea haha. What kind of problems? Council problems, or water problems? It's build on a slope, so I figure as long as drainage is good on the uphill side I should be fine from a flooding perspective. :)

      • Both, AFAIK councils require it to stop moisture sucking up through the concrete (rising damp) otherwise you end up with mold and mildew in the walls and under floor coverings.

  • How would you do plumbing if the slab is already there? Doesn't it need to be done first?

    Do you need piers for the granny flat?

    I have no experience in building but these 2 came to mind.

    • Cheers for the advice. Starting out without any serious plumbing, and then intending to maybe add a small slab to the side to accomodate bathroom. Kitchen sink could be done up the side of the building through the wall, I figured.

      • It is possible to cut a slab to route plumbing pipes.

  • You need to contact professionals to do some planning and costing for you.

    You can’t do electrical yourself in Australia. If you have no experience with plumbing, best to get a professional.

    First step as said is to meet with your local council to find out what approvals and plans you need

    • Electrical is definitely a no-go, at least in terms of connection. But I spoke to a friend who is an electrician and doing trenches and most of the other prep should be fine I figure?

  • Shipping container house! Get one with a canvas side panel and install sliding glass doors.

    • Really tempting! My problem is I'm on a realllllly tight budget. I don't have a job (so only a very small amount of money) and the parents are cash tight already. The whole point of this is to keep it livable and decent for the bare minimum. :)

  • Professional: Electrical (cabling from distribution box, breaker box and internal switches and cabling), Plumbing (water inlets, toilet, water heater, waste, trenches etc), gyprocking.

    Self: Insulation, painting, carpeting (tiles), diy cabinets, flyscreens.

    Self could include picking appropriate plumbing and electrical items to suit your taste(sink, toilet, taps, shower, water heater, lights).

    • Gyprocking isn't that hard, although I'll admit that a pro would have done a much quicker job than I did on mine, and probably a little better finish. You might also find that hanging your own sheets and getting a pro to do the jointing might save some coin.

    • Yeah, why leave gyprocking to the pros? I've heard it's fairly easy to do? Anything to save money. :) Any particular reason not to dig trenches and lay basic pipes yourself? I would probably leave connections / internal aspects to the pros, but laying pipes in the ground doesn't strike me as very difficult?

      Is there any legality issues with doing your own lighting? Does it void any insurance if you do so?

      • Anything to do with 240volt mains power other than changing a light globe is supposed to be carried out by a licences sparkie.

      • For gyprocking, it's a balance between your time and money. If I did it, it would take a week at least, and involving inhaling lots of fine dust which I am allergic to. Fine dust gives me a splitting headache. I would also need to transport large gprock sheets and I don't have a ute.
        For the trench, most backyards are compacted so hard that to dig a hole for a tree would take 30 mins let alone a 12-18 inch deep trench from the flat to the sewage system. A bobcat will also dig a flat based trench which will ensure the pipe does not flex over time as the backfilled trench begins to recompact. You don't want a 10m long underground sewage pipe to crack after a year. Look for a plumber who owns his own bobcat. He can also dig an additional trench for electrical cabling while the bobcat is onsite. You can probably do the job if it is a very short trench or if it is soft ground.

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