Better to use Bearer and Joists or Slab?

Hi,

I am considering the idea of owner building on my block of land, I'm doing some preliminary costings to determine potential feasibility of the idea.
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I have two general questions I'd like to get some advice.
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• I have a flat block. 250square house to go on it. Economically, is it "generally" considered more expensive to lay a slab or use bearers and joists? (M class slab would be required). For a slab, I've determined that I should be able to get the concrete sorted for about $13000-15000 + formworks and plumbing. Does anyone know what extra costs formwork and plumbing "generally" add? Assuming that I will be employing someone to do it.
• Is it more expensive (generally) to purchase prefab trusses and frames than making them yourself(cost of wood, nails etc). I'm not talking about install, as I will do that myself.

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Please note, these are very general questions, and I'm certainly not expecting anyone to provide details specific answers. Just general opinions from experience or knowledge. I really appreciate any advice
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As a final note, I've read mixed reports about whether it is worth it to owner build? Certain Project home companies are building 45 square homes for 200 odd thousand+ site costs, and they don't look half bad. That’s less than $500 a square metre, which would be very hard to beat in todays climate.

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Greetings Art
I'm surprised this post hasn't been replied to as yet with so many avid timber floor posters around.
I'm not biased so I'll say generally if the site has less than 300mm fall over the house area then a slab will be more economical.
Having said that there are a lot more considerations to look at such as the style of the home & whether it would be better suited to a slab or a raised floor for looks [& resale] etc.
As far as the roof trusses go - you can't make them. You can build the roof 'stick by stick'. As to which is cheaper usually comes down to how wide the open areas are.
As for the wall frames, prefab will be quicker & dearer than constructing the walls yourself on the proviso that you can buy the timber at the right price & that you have an inkling of how to go about it correctly.
Hope that helps for starters.

Art,
do you work full time? If so, when are you going to build your house? Time is a very big factor and a slab, formed and placed/finished by a pro will significantly reduce building time. A pro will supply formwork which will save you having to buy a heap of timber which you won't really be able to use for anything else as it will have dags of concrete all over it.

You can buy prefabbed trusses or you can pitch a stick roof. The latter is time consuming and can be quite tricky. If you've never pitched a roof before, imagine it's a practical geometry test, but every time you work something out wrong it means you waste a few $$ worth of timber.:(

You'll easily stand a roof full of trusses in half a day with two blokes and a crane if you know what you're doing. the same size roof hand pitched might take a week or so. (time = $$$$$$$$$) Can't comment on prefab wall frames as I've never used them, but they would certainly save you lots of time.

Is it worth it? Depends, how much time can you spare? How much money could you make in the same period if you were at work instead? What skills and tools do you have? How much do you need to learn? Watch a good chippie framing a house and it will look easy, if you've never done it before and you haven't spent much time on a building site you may be hard pressed to do it in twice the time, and chances are it may not be square and true.

Pros:
you may be able to save money (maybe)
job satisfaction
learning new skills
able to incorporate your own touches/features

Cons:
it may cost you more money
it may cost you lots more money
it may be a very stressful experience
it may cause marital problems (I'm not kidding, seen it happen)
you won't have much of a life while it's happening
you may make mistakes that you won't identify until much later
you may find it difficult to get good tradesmen, after all the good ones are generally pretty busy with an established clientele.
you generally won't get the sort of discounts that people in the trade will get.
You'll probably need to spend a lot of money on tools (Some might say that this belongs in the "pros" section:D )
You'll probably need to hire some equipment and scaffolding which most builders/tradespeople would own.

Not saying you can't do it, but judging from your questions you would have a very big, steep and potentially expensive learning curve ahead of you.

Mick

Art
The only person I know who did a successful, low stress owner build was employed by one of Abignano's subsidaries as a project manager. He built residential tower blocks for a living, could cajole his subbies into working for him between fitting out a block of units, knew at a glance what work was to spec and what was shonky, and was not fazed by using a big piece of kit where a normal builder would use something small.

The point? Despite all his experience and knowledge and preparation he still got burnt by his floor tiler who insisted on using a screed bed on top of a slab specially prepared so the tiles could be glued straight on with the result that where the tiles change to carpet there's a small step that shouldn't be there.

So how much building experience do you have?
How much are you willing to learn before you start?
How much TIME do you have?

ian

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Originally Posted by journeyman Mick

Cons:
it may cost you more money
it may cost you lots more money
it may be a very stressful experience
it may cause marital problems (I'm not kidding, seen it happen)
you won't have much of a life while it's happening
you may make mistakes that you won't identify until much later
you may find it difficult to get good tradesmen, after all the good ones are generally pretty busy with an established clientele.
you generally won't get the sort of discounts that people in the trade will get.

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It will almost certainly cost you more!

I don't want to sound harsh, but if you need to ask the questions above, you don't yet have the resources to build in a way that will save money.

Don't think you will learn as you go along (you will learn a good deal), but there is a price you will pay for your education.

Mick's comments on time are very valid, although I don't know of an owner builder who would be capable of finishing in only "twice the time", so again you will have to factor a greater interest cost into your equation.

Remember that finance will also be difficult to obtain. The finance institutions know only too well the hazards that beset owner-builders.

Finally, see all of Micks "Pro's". If either of the middle two are more important to you than cost, then you should give it a go!

Cheers,

P

Quote:

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Originally Posted by journeyman Mick

Pros:
you may be able to save money (maybe)
job satisfaction
learning new skills
able to incorporate your own touches/features

Cons:
it may cost you more money
it may cost you lots more money
it may be a very stressful experience
it may cause marital problems (I'm not kidding, seen it happen)
you won't have much of a life while it's happening
you may make mistakes that you won't identify until much later
you may find it difficult to get good tradesmen, after all the good ones are generally pretty busy with an established clientele.
you generally won't get the sort of discounts that people in the trade will get.
You'll probably need to spend a lot of money on tools
You'll probably need to hire some equipment and scaffolding which most builders/tradespeople would own.
Mick

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Hi,
Just some comments from our own owner-builder experience (we co-ordinated all trades, and started with an awesome carpenter who got the whole frame up for us):

Pros: Except for the saving money part, all correct,

Cons:
- We were about $100,000 over the original budget (often due to thinking we would do stuff ourselves, sometimes design choices meant a later trade was very very expensive)
- Very stressful at times, we had a pregnancy, major accident and cancer treatment between us during the building period
- No life on the weekend for nearly 4 years
- Didn't have too many issues with trades, we were in the country and formed some excellent relationships
- We spent at least $1000/month on building, had to be able to service this as well as the mortgage
- Our bank was OK but inexperienced with OBs, and we had to hold large equity (25%) the whole time, I've heard figures as highas 40% equity for other lenders

GO IN WITH YOUR EYES OPEN! And remember the risks of what could go wrong. We are about to build our garage/studio, and we are not touching it, getting our original carpenter/builder back to do it from start-finish, not worth the headaches.

Cheers
Justine

Thankyou for all your comments and suggestions above. Much appreciated.

I certainly won't be venturing into this blindly, and will do all my research and due diligence well before I start considering building.

The general consensus seems to be, it's not worth it if you are doing it for a cost saving.

Since financial considerations are one of the main drivers(i.e I want the architechural style home for the project home price), I believe the only way that you can save money is pretty much do ALL the labour components yourself. Would people agree with this statement?

I've also been told that labour constitutes 40-60% of the building costs(rough estimate again). So logically, the only way you could lose if you make mistakes and require trades to step in and fix the problem at "premium" rates. That is a very large cost base saving. Another consideration is as long as I could source materials at a reasonable price.....(the big unknown)...., I'd like to think I could save. Tradeconnect.com.au etc seem to provide reasonable priced materials, but I'd really like opinions on whether these are close to competitive with the trade pricing.

I'm aware that this is a potential HUGE learning curve, but i'd like to think the means is worth the ends. I'd also like to point out that I'm not trying to save against a prolect home builder who charges 500-600 per square metre, but more against the Architectural building company who charges 1200-1500+ per square metre.

Any further thoughts or comments?

HI Art

I have never, ever been to an owner builders house that has been completed fully. Im sure it happens but I have just never seen it.:o

Have you thought of moving an old place and doing it up.

Good luck whichever way you go.

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Originally Posted by journeyman Mick

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Good post.
Some excellent advice in this thread. I'll just add that even if you coordinated the whole job as an owner builder, you still wouldn't be able to do it in under the square metre cost of a project home. Their scale means they get big discounts on material, and the mass production aspect saves on labour. Even on site, the contractors work on a set price which is usually lower than any quote you'd get. They do well because they can do it blindfolded. If you did all the carpentry and labouring yourself then you'd save, but how much time do you want to invest?
Re the trusses issue. It generally costs the same in material to frame a roof as the cost of the trusses. There's more timber in a conventional roof, and truss manufacturers get bulk discount on material. Of course trusses go up a lot quicker so the only reason you'd frame a roof conventionally is if it's a small job.</post>

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Originally Posted by Art Martin

......................I've also been told that labour constitutes 40-60% of the building costs(rough estimate again). So logically, the only way you could lose if you make mistakes and require trades to step in and fix the problem at "premium" rates. .........................

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Art,
other potential losses:
loss of income whilst you are building- 6 months? 12 months? 18 months? 24 months?
interest paid on loan whilst building, again how much longer will it take you to build than the pros?
Rent paid on accomodation whilst you are building
Cost of extra labour? When you say you want to build it yourself I assume you realise that unless you're superman you won't actually be able to do it all by yourself. Standing wall frames and trusses or pitching a roof, lifting beams and bearers are all activities that go more than twice as fast with a good offsider. You'll need to find one, pay them and pay their super and workcover.
You'll also need to take out insurance(s) and the longer the period, the more you'll pay.
Hire of site toilet
Hire of scaffolding, if it takes you twice as long to do something, then you'll need to pay for twice the hire.
Etc etc etc
Site lock up? where are you going to lock up tools and materials? Hire a shipping container or will you sell the family car and buy a ute to cart all the gear from home every day. Maybe get a tool trailer instead- more $$.
Do you own all the necesary gear? Are you prepared to spend the money top get it and then sell it all when you're finished to defray some of the costs.

Time = Money

Materials:
My local harware store (which is a pretty big concern and has managed to grow since Bunnings came to town) has a tiered pricing structure, retail and then trade 1 - 5. If as an owner builder you open an account you'll get trade 1. Most tradesmen get trade 2, increase your volume and you get trade 3 (I'm a 3) Most builders etc top out at 3. Then when you start building lots of stuff, maybe having 3 or more crews and doing lots of volume you move up to a 4 or 5. You will definitely pay more for your materials, how much more I can't say but on the cost of your house it would run into a few thousand at least.

And then, like I said before there's all the things you can't put a $$ value on: Time away from family and friends, stress and lots of it.

I've dome some owner builder jbs in the past and made some good friends out of some of the clients. There were some jobs where the clients did save money, but that was because they had me doing the job. Not trying to boast or anything, but I delivered quality work, taught them skills, channelled their labour into tasks they could manage and which would save on labour costs, sourced other tradesmen and project managed for them. I've got some current clients that I work for every time they get a bit of money together. They had some major horror stories to tell about the beginning of their project and were fortunate to find a mate of mine to take over from the first dipsticks that were wasting their money.

Art I really think you're underestimating the time and skills required to build a house. For instance, lets say you go ahead, do you know how to do a set out? If you get this wrong it will cost you thousands in problems down the track. You can read about how to do it and probably get step by step instructions, but seeing it done would be worth a lot more. Depending on the complexity of the building and the terrain it might take me and an offsider a few hours or a day and a half. By yourself, without experience and with only "book learning" it may take you up to a week to get it absolutely right. That's a week of income you'll miss out on.

Mick

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Originally Posted by Art Martin

...financial considerations are one of the main drivers (i.e I want the architechural style home for the project home price), I believe the only way that you can save money is pretty much do ALL the labour components yourself. Would people agree with this statement?

I'd also like to point out that I'm not trying to save against a prolect home builder who charges 500-600 per square metre, but more against the Architectural building company who charges 1200-1500+ per square metre.

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one reason project homes are so cheap is that the are built in standardised modules. Design your architechural home around these modules and any half intelligent project builder can build it for you at a price not much different to his own design.

BIG questions
are you looking for double brick or brick veneer?
standard height ceilings or extra height?

these will influence the final price much more than slab on ground vs bearers on piers


ian

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Originally Posted by dazzler

I have never, ever been to an owner builders house that has been completed fully. Im sure it happens but I have just never seen it.:o

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I've found that this is true, in a way. I've seen plenty of owner-builders' homes that have been finished according to original spec (ready for sale, if that's on the cards) but these same owner-builders often also change their minds about this, that or the other thing and now have at least the basic idea of how to do something about it.

So, there's still construction going on... which is usually slower 'cos the house is "finished" (Well... they and the bank may think so, any 3rd-party looking on will probably disagree. :rolleyes: ) and as they're just making "minor modifications" they're now taking their time.

The trick is knowing when to stop starting new projects and to start finishing old ones!

Why not go for a steel frame home? Something like a kit home, you could have a go at that.

Thankyou all again for your help.

Mick,
Appreciate your detailed response. Thankyou for the extra cost considerations, while I was aware of a few of them, I wasn’t aware of the site toilet, which will add to the cost. I’d also like to point out that I’m not one of those people who say, lets go gun ho and build a house, and I am not underestimating the HUGE task at hand. But you are 100% right that book skills and practical experience are worlds apart in the real world, and this is really the one thing that is holding me back.
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The reality is, I'd like to think the formula for saving money owner building is
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1. You have to do it ALL yourself(with help from friends in the trades etc).
2. You have to design your home around standard lengths, and heights of materials.
3. You need to source materials at close to trade rates.
4. You need to do it in a reasonable timeframe.
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I think that is agreed.
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Therefore, once you start owner building with the intention of doing almost everything yourself, you have to commit to the whole process doing it yourself. This is an important point. Because as soon as you start to realise that you can’t do something yourself, you have to outsource tradies at premium rates= Cost blowouts!!. Now, I’m betting that the majority of cost blowouts in owner building relate to the belief that they could do it themselves, but found out they could not, and had to pay a sh*tload to the trades to firstly, to fix their mistake, and secondly, then do the job.
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So you can see that before I even begin, I’m going to make a concerted effort to learn about the processes involved, and make sure that I am technically and realistically up to the challenge of doing the job. This is the big unknown right now.

Ian,
While I'm not sure exactly what you mean by standardised modules.… does that relate to standard lengths for materials. I.e plasterboard comes in,say 4000mm x 1200mm. So make one wall exactly 4000 and make the ceiling height 2400(2x1200)? Or are you more talking along the lines of attempting to design my home in a similar way to a specific project home design(materials, room sizes etc). Again, excuse my ignorance, but I’m in a very prelim stage. Definately looking at brick veneer(or blueboard and render) whichever works out best value. As well as standard heights.
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Originally Posted by Art Martin

Ian,
While I'm not sure exactly what you mean by standardised modules.… does that relate to standard lengths for materials. I.e plasterboard comes in,say 4000mm x 1200mm. So make one wall exactly 4000 and make the ceiling height 2400(2x1200)? Or are you more talking along the lines of attempting to design my home in a similar way to a specific project home design(materials, room sizes etc). Again, excuse my ignorance, but I’m in a very prelim stage. Definately looking at brick veneer(or blueboard and render) whichever works out best value. As well as standard heights.
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I disagree with Ian there. Project home builders work to mass production scales on a set number of floor plans, and whilst they may offer slightly different floor plan options, and you could make minor changes without incurring too much extra cost, you won't get the same price if you give them your own plans to work off.
Re standard sizes, plasterboard is only a very minor cost consideration. Standard sizes go in increments of 600mm. ie 2400, 3000, 3600 etc. You can get in between sizes such as 2700 by cutting a 5400 in half. Personally I wouldn't have a ceiling at the minimum 2400 height. It doesn't cost that much more to make it 2700 high and two sheets of plasterboard at 1350mm will get to the ceiling. Better yet, I'd make it 3000 high and use one and a half sheets at 1200mm high.
No offense, but it looks like you really don't know that much about building, so the only reason you'd build yourself would be the satisfaction. You certainly won't save any money over a project home and you could end up spending a LOT more.

edit:- Why don't you hone your skills by buying an old house and renovating/extending. You might make a profit that way and you could live there whilst you're working on it.