How Does A Builder Figure Out The M2 Price?

[scooterboy]

Hi Guys,

Something that I've wondered about a few times.

When building a house there are obviously the normal "room" measurements - plus the more external areas, such as carport, roof extensions, terraces and the like.

How does a builder actually arrive at a price per sq.m.?

Does he perhaps use the total roof area, or are there separate sq.m. calculations for rooms and for terraces/carports?

I ask, as it strikes me as being more difficult (and costlier) to build a room, rather than a terrace/carport.

Anyone have any idea?

Thanks

[IMHO]

I'm sure they all have their own different means...

Some do calculate based on whether it's a closed or open space, and whether it's floor #1 or floor #2, and again different rates for different grades of finish.

Others will base their quote on the BOQ and calculated man-days needed, even if the final number is presented as Baht/sqm.

Others might just quote per sqm prices based on what their competitors are asking (i.e. match the market) with not too much thinking needed.

[scooterboy]

Thanks, IMHO - that's probably the answer I was expecting...inasmuch as there are no real predetermined rules to what constitutes a "sq.m." when assessing prices.

As you point out, there are both closed and open areas - and if I have a total of a 100 M2 rooms plus 50 M2 carport and terrace, will the builder charge 10K per sq.m. for the rooms and - say, 5K (or less) per sq.m. for the carport & terrace, or will he charge 10K @ 150 M2?

The mind boggles...

Too, there are the BOQ figures or maybe whichever way the wind's blowing....

Interesting, though still pretty confusing....

Cheers

Edited May 12, 2014 by scooterboy

[IMHO]

Thanks, IMHO - that's probably the answer I was expecting...inasmuch as there are no real predetermined rules to what constitutes a "sq.m." when assessing prices.

As you point out, there are both closed and open areas - and if I have a total of a 100 M2 rooms plus 50 M2 carport and terrace, will the builder charge 10K per sq.m. for the rooms and - say, 5K (or less) per sq.m. for the carport & terrace, or will he charge 10K @ 150 M2?

The mind boggles...

Too, there are the BOQ figures or maybe whichever way the wind's blowing....

Interesting, though still pretty confusing....

Cheers

If the "open" areas still need footings, beams, posts, floor, ceiling, roof and electrical, there's no way they're going to come in at 50% (or less) the price of a closed space - you might save 10-20% depending on what windows/doors it doesn't have, and what type of blocks the walls it doesn't have would have been constructed of...

Then again, if the open area is just a ground slab, with precast posts, no proper footings, and a fiber roof with no insulation or ceiling, it could certainly only cost 5K/sqm, or less

[scooterboy]

Very true, some "open" areas could have roof and walls, though something like a terrace would possibly not. Likewise, some open sided carports, (open) roof extensions and whatnot would have relatively less work needed, compared to the normal "rooms".

I'm not eager to present a plan to a builder, just to hear that it would be far too expensive to build - and then have to redesign everything. Better if I could "guess" beforehand, to a certain degree at least, just how many sq.m. I have to play around with.

Still, nothing's easy, is it!

Thanks for your input - appreciated.

Cheers

[eyecatcher]

I am a quantity surveyor and the price per m2 is simply the total material and labour cost of the job...whether it be garage, house,hotel,school divided by the total floor area.

You can sub divide this again to include foundation in the ground floor and roof in the upper floor.

If you cost everything up as a mid range price then you can easily estimate a cheap build as being say _20% and higher quality at +20%

When you have prices up several different houses a pattern will appear for an average build for example 12k/m2 for ground floor, 6k/m2 for sub floor and founds 15k/m2 for upper floor and roof and 6k/m2 for car ports balconies,paved areas,

Those rates are considered good quality build rates, but each job is different.

So when a developer sees a plot of land and he knows he can build 100 houses on it, its a pretty simple task before any bills are produced to cost up the job, work out a profit margin in order that he can put a bid on a plot of land.

Simple

[scooterboy]

Great - thanks, EC!

We're not thinking (yet, anyway!) of a 2 storey build, just a pretty normal bungalow type thing. No special requirements, as such, except some built-in kitchen cupboards. Oh - and large windows in living room and in 1 bedroom - if that's considered a special requirement.

No fancy schmaltz, no exotic bathtubs (actually, no bathtubs at all), no split level rooms, teak floors, swimming pool or fancy fountains.

Just a normal house - strong and well-built (well, we can dream, eh)...

Thanks for your reply - most informative!

Cheers

[eyecatcher]

There are many architect designed houses in the books you can but at most large bookshops, such as dk books if there is one in your area or see.ed? The one always in a tesco/big c mall.

Typical house designs all with approx cost, and a guide to estimate your own build.

to err on the side of caution with a bungalow budget on 12 to 15k all in per m2, .....that really is generous and will help you decide whether your builders are taking you for a ride.

[scooterboy]

Thanks again, EC - some very useful information, there.

Still, 12 - 15K seems a bit on the steep side for a rather 'ordinary' build - especially as this area is up-country and just a small village, to boot. No See Ed or DK Books, either - in fact, no bookshops at all.

Whatever, guidelines are always welcome, as they are exactly that - guidelines!

Thanks - much appreciated!

Cheers

[alfieconn]

A professional builder doesn't, he will he give you a price based on the drawings which obviously includes all the materials used.