To Build up or out the back???

Hi all,
Its that time when the existing home is a bit too small as the kids are getting older and noiser but its too good a spot to leave. We want to build a "parent's Retreat" in our exisitng brick veneer home.It is on two levels with a Garage /workshop and 4*5 metre bedroom on the lower level and up the stairs to the main living level which is 17m*8m. (Sorry I don't know how many squares that is). This llevel exits to ground level as the house has been built on quite a steep slope. It is buitl on strip footings with double brick to the floor level at the front and besser block and brick skin on the lower high side. From floor level it is single brick. it has a 22.5 hip roof with trussses.

We want to build a parents retreat that is away from the kids bedroom. We want a bedroom and sitting / tv room with a bathroom and toilet. At first we thought we should build up to a 2nd level by sing one of the smaller bedrrooms for the stairs and turning it into a study. We would have the bedroom /sitting room and bathroom up the stairs (about 32sq metres) with the new bathroom right above the existing main bathroom
The other option which is beginning to be much more attractive is to build onto the back of the house. The area is flat, there is plenty of room and if we added the same amount of space we wouldn't loose a room to stairs. I anticipate that the extension would be on a slabwith plumbing going through the existing lower foundation wall walll to meet all the othe plumbing which is readily accessable under the house. it would be timber framed with brick veneer and the existing line of the roof would simply be extended.This approach would enable us to also utilise the existing main bedroom, reconfigure the interior space, keep the views we love and hide from the kids.

Condsidering I am competent to paint, fit trim, hang doors, tile spaces ect what would be the cheapest option Going up or going out???
If I can figure out how I'll post some sketches that might help.

I look forward to any and all contributions.
Cheers
Jock

I think there was a time when going up would be cheaper but not any more. For a two storey place you will need scaffolding all around and that will add thousands to the cost. Then there's the stairs when you get older ;)

I have the same predicament.

Going up will be substantially more exy than going out. Problem going out is the new shade pattern (right across the pool??), loss of yard and potential built upon council limits.

No argument re costs tho.

We have absolutely no impediment to going out as neighbours wouldn't even see the extension. The new area wold still face north east and the view is still perfect.
What about the cost? Does anyone have any estimates per square metre given that it will be built on a slab framedwalls, brick skin, Aluminium windows and roof on trusses. As i said before I ammore tan happy to finish it off inside but while I love plastering I would probably pay someone to finish the plaster off
Jock

It's NEVER been cheaper to go up. That's just a myth propogated by the magazines and the companies that specialise in "first floor additions",
go out, and you also won't have anywhere near the disruption either.

Cheers,

P

Sell the children. Cheaper still.

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It's NEVER been cheaper to go up

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A bloke I worked with about 15 years ago (he was an accountant) had done his due diligence on this. He reckoned that by the time you excavated and poured a slab and paid for the extra roof, it was cheaper to go up, assuming that the existing walls and footings were up to it (which in his case they were). His roof was tiled and he planned to reuse them. He was just raising his building footprint, no change to shape. I think he even intended to reuse his roof framing. This was based on quotes from builders for the job and talking to people. Of course he didn't have to factor in upwards of $1,000 per week for the scaffolding. That may be a special case but my Grandfather, who was a builder, always preferred to go up than out. But then he would have straightened out every nail and reused every bit of timber from the roof and probably the iron as well.

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Does anyone have any estimates per square metre

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About $1,000 per sq metre seems about right as a rough guide. Of course you'll save money on the labour if you do it yourself. I've just built two houses and I reckon I've saved about $30,000 on labour doing things myself - based on $35 per hour. But then I probably take longer to do things than someone who does them all the time. Cost of the job was about $500,000, so that's roughly a 6% saving. Not a big discount I don't suppose.

Are there any 'design & development' overlays on your site ?
Some 'DDO's' limit the height you can build to.
If you're unsure, the councils planning dep't. will let you know over the phone.

When we built up about 30 years ago, our bank manager told us to put the kids upstairs as our knees would not like the stairs as we got older.
We did and he was right

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Originally Posted by Chesand

When we built up about 30 years ago, our bank manager told us to put the kids upstairs as our knees would not like the stairs as we got older.
We did and he was right

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& it's harder for them to sneak out !

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Originally Posted by silentC

He reckoned that by the time you excavated and poured a slab and paid for the extra roof, it was cheaper to go up, assuming that the existing walls and footings were up to it (which in his case they were).

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Yep, I've seen heaps of builders estimate that is is less cost to go up. I've never seen anyone actually document both alternatives and get firm QUOTES who has gone up, and I've been paid to develop two schemes on quite a few occasions.

I don't know why they love it, except that it IS quite profitable work.

It's a bit like trying to convince people they can build a completely new house for less money than a renovation.

I don't understand (yet I know they do this) how houses can support the extra floor legally without a good deal of modification. I've NEVER seen footings designed to support them and constructed "just in case". Likewise I've NEVER seen timber stud walls put in oversize "just in case".

IF you could reuse the existing stud walls and footings exactly as they are, the current cost of double handling a tile roof is about the same as a new one, a timber floor is much more expensive than a slab on ground, you'd be building four external walls not three, a stair (there's a couple of grand) and replacing ceilings and cornices over the whole area.

Going out means a few roof trusses, which would be less than the cost of the stair.

It just doesn't stack up!

Cheers,

P
:D

The guys across the road did it to a 50 year old house. The engineer designed some ruddy great beams to support the new upstairs and they ran triple studs to support them down to the masonry walls below the first storey. The builder just smashed off the cladding in the appropriate places, cut out noggings, and whacked in the new studs. Most of it is still bearing on the original foundations.

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Originally Posted by bitingmidge

I don't understand (yet I know they do this) how houses can support the extra floor legally without a good deal of modification. I've NEVER seen footings designed to support them and constructed "just in case". Likewise I've NEVER seen timber stud walls put in oversize "just in case".

IF you could reuse the existing stud walls and footings exactly as they are, the current cost of double handling a tile roof is about the same as a new one, a timber floor is much more expensive than a slab on ground, you'd be building four external walls not three, a stair (there's a couple of grand) and replacing ceilings and cornices over the whole area.

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About 30 years ago I put on a major double storey extension part of which was above, and incorporating a smaller stand alone bungalow.

Whilst the timber wall frame of the bungalow was okay for the extra storey, the council required me to underpin the concrete slab, and where the staircase rests a large concrete pad into the floor and a new concrete floor surface.

If I had been paying for the extension it would have been cheaper to knock the bungalow down and build from scratch, but as I wasn't :D I didn't. ( I was working for a large homebuilder and all the subbies and most suppliers did the work gratis :D )

Incidentially the roofing company would have charged the same for supplying new roofing tiles as reusing my old ones.

So going out seeems the cheaper option.


Peter.

I recommend going out back over going up, unless there is a compelling reason to do so like killer views or space constraints. As mentioned, no stairs to manage when older..... a nicer "flow" through the home to all rooms.....cheaper to do it and easier if you are doing any of the work yourselves. No scaffolding, no restructuring of foundations, thereby running the possibility of destroying the existing conditions..... and so forth.