Raft costs per square metre

[Alan Ambrose]

Morning. Anyone with a raft have an example cost? @marshian ?

[marshian]

1 hour ago, Alan Ambrose said:

Morning. Anyone with a raft have an example cost? @marshian ?

 

Last one I did looked like this but it was years ago - Cost was pretty much free as most of the wood was scavenged

 

 

Sorry didn't build the house so no idea on costs

[kandgmitchell]

Last year ours was £260/m2 (i.e £26K for 100m2) for stone, then 150mm XPS, 250mm r/c slab and 100mm perimeter XPS plus 4 No. 100mm drains to outside slab area ready for onward connection.

[JohnMo]

2 hours ago, Alan Ambrose said:

Anyone with a raft have an example cost

Think you may need more details - what sort of raft and spec?

 

We did a concrete raft, but there were also strip foundations under and around it, on difficult site, so our costs may not be want you are wanting.

[Gus Potter]

12 hours ago, Alan Ambrose said:

Morning. Anyone with a raft have an example cost?

Post your design drawings if you want and see if folk on BH can put some reasonable cost numbers / suggestions to this.

 

In terms of pricing raft slabs ideally we want to split out any excavation and back filling cost from the slab and then further split out the insulation cost.

 

 

 

 

 

 

[Gus Potter]

10 hours ago, JohnMo said:

We did a concrete raft, but there were also strip foundations under and around it, on difficult site, so our costs may not be want you are wanting.

Fair enough if you take the slab in isolation.. but often these things require a holistic approach.

 

As a designer folk often ask me..

• why is your raft slab thicker.. I've seen some slabs at 100mm thick internally.. and I say because that little extra thickness allows me to shed load into it which makes the other parts of your design cheeper.
• Why have you got the extra complexity in my attic conversion.. often because it lets you get the stair to fit and complies with BC regs
• We are renovating a historic building so we can't apply standard rules and need to design from first principles this is the way to go I say.

 

 

[Alan Ambrose]

Ah, to report back - I was recomended a QS as a way to solve the 'am I getting a reasonable price' problem. That's where there were few apparent takers for the job.

 

That worked a treat. The QS thought the bid from the single contractor was fair.