Estimating an OB in Adelaide

Dels · Dec 06, 2020 8:00 am

Hello

I'm thinking of building a house and looking to come up with realistic estimate of costs to help with the decision making process, to either go forward and buy land or decide to continue looking for an established house.

I'm fairly handy, have renovated a few properties and am fairly good at a number of things like carpentry, plaster board finishing, painting, tiling etc, however I'm also happy for others to do these things, so I'm looking to cost the services I can do, in the hope that I don't !
I also know there are somethings that if not done correctly you can't recover from, like the concrete slab, frame, bricklaying and roofing, so think there's value in having a registered builder having ownership over the core build, rather than a swag of contractors that just do their own piece and have no skin in the game, so I'm looking to have a builder get the roof / brickwork in place.

I've got an engineering degree (outside of the construction field), and work in designing / managing software projects, so I'm good at planning / estimating and managing contractors, so I think I can owner build. I know everything is an "it depends" so not looking for someone to tell me how much to build a house, but I am looking to understand the core costs which should be fairly common, like slab / framing / roofing.

Does anybody have that kind of information from their OB experience, or know of good source of information ?
I've attached an image (I can sort out a link if desired) of the spreadsheet I'm looking to complete in order to decided whether to move forwards or not, and also engage a builder who has the same expectation of costs.

Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅

Thanks in advance

StructuralBIMGuy · Dec 06, 2020 9:47 am

Hey dels Welcome to the forum
You can approximate Builders costs quotes/easily with programmes like Matlab using Bim solvers, but
Why bother for a one off house and if you aren't in that game?
My 2c
1.Do your own 3D Bim design & engineering, own copyright on the plans and data,
2.Ask 3 builders to sharpen their pencil and quote to lock up stage, I am sure you will be able to do/organise the finishes yourself
3.Just remember larger building firms have large overheads and what appears to be good value initially at the sketch stage may not be after compliance, variations, engineering, prestart, etc,etc.
Ot, It doesn't matter how accurate your estimated cost/ prices are, but whether you can find someone to do it for a fair/reasonable agreed price be prepared to offer a bit more during busy periods
Prices have gone up because of the builders grant, though that's not going to last long
lol, BTW hiring people with skin in the game, means bugger all when things start going wrong onsite
Cheers
Chris

Thylacene · Dec 08, 2020 5:09 pm

Approaching completion on my owner build, with the exception of finishing the slabs, fitting fascia gutters and roofing I have done everything else up to fit out.

100m2 of 3.2 to 3.8m colorbond shed, with bathroom, kitchenette and laundry facilities, wired for workshop in the future. Total cost about $140k including plans and DA Costs and 8k electrical and 9k plumbing

212m² house, includes 50m² of decking and 37m² of concrete entertaining area.

Plumbing about 8k, electrical and data $13k. Steel framed, on a Spantec flooring system. Finished to a mid level standard, kitchen $38k fitted with miele appliances. 113m² of internal living, 9-12 ft ceilings, spotted gum flooring. All up will run to about $330k.

Tiling bathrooms at this point, and have occupancy. 2 years 3 months of my time. 9.months hire for a labourer.

Light weight construction on a moderate slope with stairs down to laundry under.

Final spend on the whole project for construction will run to about $470k.

Hope this helps Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅

Dels · Jan 10, 2021 7:25 pm

StructuralBIMGuy

Hey dels Welcome to the forum
You can approximate Builders costs quotes/easily with programmes like Matlab using Bim solvers, but
Why bother for a one off house and if you aren't in that game?
My 2c
1.Do your own 3D Bim design & engineering, own copyright on the plans and data,
2.Ask 3 builders to sharpen their pencil and quote to lock up stage, I am sure you will be able to do/organise the finishes yourself
3.Just remember larger building firms have large overheads and what appears to be good value initially at the sketch stage may not be after compliance, variations, engineering, prestart, etc,etc.
Ot, It doesn't matter how accurate your estimated cost/ prices are, but whether you can find someone to do it for a fair/reasonable agreed price be prepared to offer a bit more during busy periods
Prices have gone up because of the builders grant, though that's not going to last long
lol, BTW hiring people with skin in the game, means bugger all when things start going wrong onsite
Cheers
Chris

Hello StructuralBIMGuy

Thanks for the response and apologies for my late reply.

With regards to 3D BIM, my plan was to use SketchUp as I'm familiar with it having used it for numerou renovation projects before. One outcome would be the knowledge of surface area sizes, which are an input to the costing, however I had presumed the main outcome of the diagrams were as a visualisation / communication tool to explain the build to my wife / potential builders and contractors etc.
The costing I was going to manage in a spreadsheet (i.e. cost per m2 of wet area * actual size of wet area etc ).
* However I think I'm missing a trick and that you're suggesting some modelling solutions have a plugin to help with costing ?
I used MATLAB at Uni but that was for simulating electrical circuits / signal process, I'd be lost trying to use MATLAB to design a house - can you point me at some examples / tutorials (my googling didn't find anything).

You commented in a historic post (viewtopic.php?f=38&t=84797) that your 3D BIM Details & Data are in your signature - however Google appears to have retired that community - are you able to share via a different platform ?

Thanks kindly
Damian

Dels · Jan 10, 2021 7:37 pm

Hello Thylacene

Thanks for your response, 330k to build your house is really encouraging and helps me with motivation to push on

Did you build the frame yourself or did you have hire a carpenter(s) for that piece ?
Either way, do you have information on the materials (per metre / square metre) and then hours / rate for labour ?

From the images it looks like cladding exterior - does your house have any brickwork ?

Thanks kindly
Damian

Thylacene

StructuralBIMGuy · Jan 11, 2021 9:39 am

Dels

With regards to 3D BIM, my plan was to use SketchUp as I'm familiar with it having used it for numerou renovation projects before. One outcome would be the knowledge of surface area sizes, which are an input to the costing, however I had presumed the main outcome of the diagrams were as a visualisation / communication tool to explain the build to my wife / potential builders and contractors etc.

By the time you add all the plugins into sketchup pro the price balloons significantly, so you are better off using other programs
Not Only is 3D Bim a good visualisation tool, it's also a good training tool for trades to use on site. At the other end of the trade spectrum are the " I've been doing this for 20 years...experts" who aren't up to date with compliance and don't read notes... It is also there to assist them as well. Clients also have access to them as well and they will soon advise me if things aren't right. win-win as mistakes are picked up early

Dels

The costing I was going to manage in a spreadsheet (i.e. cost per m2 of wet area * actual size of wet area etc ).
* However I think I'm missing a trick and that you're suggesting some modelling solutions have a plugin to help with costing ?
I used MATLAB at Uni but that was for simulating electrical circuits / signal process, I'd be lost trying to use MATLAB to design a house - can you point me at some examples / tutorials (my googling didn't find anything).

You commented in a historic post (viewtopic.php?f=38&t=84797) that your 3D BIM Details & Data are in your signature - however Google appears to have retired that community - are you able to share via a different platform ?

Thanks kindly
Damian

Spreadsheets are fine for basic housing, but they can't produce reports, analysis and details, that's where matlab comes into it's own. You just have to look at the 3D Bim processing and mining industry software lead by engineers to realise that it is light years ahead of architecture and the likes of 3D Archicad, sketchup, VWs Architect. et al.
LOL "Designed by architect for Architects" ...but they forgotten everyone else, nuf said, their loss.
Unfortunately, Architects are facing extinction in the home building sector and soon will be replaced by builders with design algorithms

What was up on G+ has been taken down, Hmmm. Platform for Dynamic Sharing of Data any suggestions?

OT if you want better examples you need to contribute here where the Battlers and Punters post that are building.
Cheers
Chris

StructuralBIMGuy · Jan 15, 2021 10:07 am

StructuralBIMGuy

Platform for Dynamic Sharing of Data any suggestions?

Here Try
Excel live
Share the 3D Bim and data with the likes of @Bim Engineer, @TimberSuppliers, @TimberTradies...you get the gist
.....be kept in the loop
Cheers
Chris

microalgae · Feb 09, 2021 7:40 pm

Hey mate

Just wondered how you're going with everything?
We have a place in the Adelaide Hills. Basically we bought this house about 18months ago, turned out to be a lemon. Spent many months wasting money trying to figure out what to do with it. Have now decided to completely rebuild to lock up stage then sort out the rest ourselves. Have you had any luck finding a builder? We have found that not many are interested in building to lock up, especially right now.

StructuralBIMGuy · Feb 11, 2021 8:41 am

microalgae

Have you had any luck finding a builder? We have found that not many are interested in building to lock up, especially right now.

Right now trades are flat out creaming it on the Builders grant.
A word of warning, you can get full build quotes for the new House and then take out finishing trades by means of credits
but in the end you will wind up with less house while paying the same. Always check the builders credits with a reliable comparisons & sources. Pity you spent 18 months getting mucked around you would have missed the rush
OT trades have no problems getting Builders to build their Houses to lock-up and the clever ones got the grant as well.
Cheers
Chris

microalgae · Feb 12, 2021 1:54 pm

Thanks Chris

Yes the timing is very unfortunate! The whole property has been a disaster really. We got a building inspection before we purchased the house which we were happy with but later discovered there were severe structural issues which should have been picked up on. By this point we had already spent about 25k renovating it. So we decided to do an extension (to replace the existing part that needs to be demolished) and engaged a draftsman in Feb 2020 to get this all drawn up, we were reassured by the drafty and multiple builders that the project would be within our budget (we were told 80-100k with basic finishes like laminate kitchen, etc.).

Now we are receiving estimates of $250,000 for a 80sqm extension and being told that we'd be better off knocking the whole thing down and starting again :shock:

so we're back to square one but about 35k worse off, not to mention we paid 355k for a house that was essentially worth land value only. Very depressing. We've had a real estate agent come out and tell us that we should do a do dgy patch up job and sell it onto the next poor bastard.

I am sending an email to my local member of parliament today because I am just so disgusted by the whole thing. But my main concern now is getting a new house built without somehow being fleeced by the next person that comes along.

StructuralBIMGuy · Feb 14, 2021 10:25 am

Hey microalgae
Sorry, It's sounds like a never ending night mare
I'm a firm believer in that you should keep the design/engineering separate from the build
Your documentation should include engineering, data/proof and costs armed with this, seek out 3 builders to quote.
OT, Unfortunately the governments' poorly implemented Builders Grants to home owners is cause of great angst.
Well aware knowing, its a temp fix and causing more pain than gain for the home owner.
Write/ post online/petition the politicians.
They screwed up in giving you the sense of security that the money was going to make building more affordable.. it had the opposite effect
Regards
Chris

Thylacene · Apr 01, 2021 9:36 pm

Dels

Hello Thylacene

Thanks for your response, 330k to build your house is really encouraging and helps me with motivation to push on

Did you build the frame yourself or did you have hire a carpenter(s) for that piece ?
Either way, do you have information on the materials (per metre / square metre) and then hours / rate for labour ?

From the images it looks like cladding exterior - does your house have any brickwork ?

Thanks kindly
Damian

Thylacene

129m² house
56m² deck
40m² of open lower story on slab that is engineered to be built in if required

10k site costs
40k to floor level
30k steel frames & trusses, assembled
5k ironbark 200x200x6m posts x5
13k fascia, gutter & roofing
7.5k roofers
20k electrical
20k plumbing
8k gyprock etc
25k cladding
24k Windows
10k decking ramp and screws
11k ballustrades
10k bathrooms
25k kitchen
18k appliances
9k flooring
5k tiles and consumables
3k paint
5k 3 x reverse cycle a.c.
4k shelving and wardrobes
4k doors and hardware
12k freight
3k rendering
7k scaffold

And a bit of other stuff that all adds up

I have had no labor costs of great note as my brother-in-law helped me get it to lockup, and the neighbour helped me sheet it.

It would be fair to describe the level of finish to be moderate.

I have done all of the build except roofing, electrical and plumbing.

Lightweight BAL 60 rated cladding, low-e glazing in aluminum awning Windows, ironbark 135x19 decking, engineered spotted gum flooring, steel subfloor and frames.

Hope that helps