What does Cost per Square Foot include

[David_Dublin]

Hi. Maybe this is a silly question. I am trying to do a very high level cost of doing an extension. I intend to go to a QS when the time is right, but at the moment I havent decided what way we want to do it. When we do, we have some architects we intend talking to about design.

So....the silly question is: what is included in the cost per square foot? I know the actual cost varies completely based on complexity of build, materials used, but what would ordinarily be included in the cost? From reading posts on this & other sites, the following is what I expect are: the actual building works (foundations, walls, roof etc), plumbing, electrical, insulation. Is this right? Are other things also covered: painting, windows, doors, general carpentry etc.

I know there is huge scope for grey area, just trying to get some sort of very high level understanding of what to add on to the per square metre cost. The things I would know about would be fit out of things like kitchen, bathroom, any above standard glazing or wiring or plumbing etc.

Any advice gratefully received.

 

[Leo]

Please edit the title of your post to make it more meaningful.

 

[Docarch]

....what to add on to the per square metre cost.

What square metre cost? What square metre cost were you thinking of?

I have done extension jobs in the last year in Dublub ranging from € 1,200/m.sq. to € 2,800/m.sq. The devil is in the detail and there are so many factors in building that influence the cost.

 

[David_Dublin]

What square metre cost? What square metre cost were you thinking of?

I have done extension jobs in the last year in Dublub ranging from € 1,200/m.sq. to € 2,800/m.sq. The devil is in the detail and there are so many factors in building that influence the cost.

Sorry, I may not have put my question clearly. I understand the cost per sqm varies hugely. What I was asking is what you would expect to be included as part of that cost. Or alternatively, on top of the cost per sqm, what would you expect to have to budget for. Alser has me steered in the right direction.

 

[Docarch]

What I was asking is what you would expect to be included as part of that cost.

I'm still confused as to exactly what you are looking for. You can include anything you want but it just mean a higher cost per m.sq. Nobody will actually price the job as a cost per m.sq.? It is only generally used as a very loose rule of thumb.

If you intend to use a QS and/or architect, I would speak with them first to get some general advice.

 

[David_Dublin]

I'll give it one more try...when using cost per sqm as a rule of thumb you come up with an estimate for build cost. I think I am right in saying this. But, as Alser says, this would not usually include fees, white goods, furniture.

I know there is no hard and fast rule as to what is included, and what is not, but generally speaking, I was wondering if things like plumbing, insulation, electrical etc would ordinarily be included. Whereas, it would not be the norm to include furniture, kitchen, bathroom fit out etc etc.

Anyhow, I know what I mean, and thanks for the replies

 

[Docarch]

Hi David. I think what I am trying to get at is what cost per m.sq. have you come up with or what cost per m.sq. are you considering allowing?

If you allowed E 1000/m.sq. for a (simple) extension, you would be getting a very basic builder finish, windows, etc., and I would be adding on all the peripheral items mentined by alser above.

However, if you were to allow E 2500/m.sq. for a more complex extension you could pretty much assume all is included and to a relatively high spec!

But, as I mentioned above, I do not think that is really an appropriate way to be trying to establish a budget cost/estimate for a project.

The only time I use a per m.sq. budget cost is when a client comes to me I usually suggest budgeting E 1500/m.sq., so if they want to build a 40 m.sq. extension and their budget is E20K I would usually tell them, in reality, they are not going to get their 40 m.sq.!

 

[David_Dublin]

Hi David. I think what I am trying to get at is what cost per m.sq. have you come up with or what cost per m.sq. are you considering allowing?

If you allowed E 1000/m.sq. for a (simple) extension, you would be getting a very basic builder finish, windows, etc., and I would be adding on all the peripheral items mentined by alser above.

However, if you were to allow E 2500/m.sq. for a more complex extension you could pretty much assume all is included and to a high spec!

But, as mentioned above, I do not think that is really an appropriate way to be trying to establish a budget cost/estimate for a project.

Aaah, that penny drops with me. Thanks for hanging in there!!

I haven't really come up with a value to be honest (Docarch rolls eyes to heaven).

We'll that's not strictly true. I have a spreadsheet that tells me things I dont want to believe. I have rough drawings for a two storey build on the side of my house, replacing a single storey garage. I reckon there will be about 85sqm of build. No steels. So I was starting off with a figure of 86k or thereabouts. And then I was adding on loads of stuff, mostly fit out stuff, but plumbing too, and some electrical, completely arbitrary figures. Having done that the total was waaay more than I want it to be, so I asked the question above with a view of maybe being able to take off some of the items I had added.

I really dont want to waste peoples time, I was just asking what I thought was a simple question. When we decide on what we want to build, we will do it the right way, i.e. properly costed, assign a QS, have it project managed etc. Actually, I have a few questions on that so will add a new thread, maybe have a look out for it....Thanks all for the replies

 

[Docarch]

I have a spreadsheet that tells me things I dont want to believe.

I know that feeling!

Now we're suckin' diesel! Sounds like a big enough build and a simple enough build to grab builders interest (i.e. you should get good/competitive pricing for a job of that size).

You seem to be sort of on the right track. I would start at E 1,000 / m.sq. for the build/basic builders finish, including probably bog standard interneal doors, PVC windows and external doors, basic electrics, basic plumbing and heating, etc., etc., and then work up from there adding in the peripherals like sanitary ware, floor finishes (tiles or timber flooring) and extra/over costs where you want a higher spec (like for example maybe alu-clad timber windows and external doors).

You could save yourself a bit of time and headache by maybe asking a QS to do a preliminary budget costing for you which would/should include your specific wishes/requirements. This might cost you E 250. Might be a worthwhile exercise? With that under your belt, then you could approach an architcet to flesh out the plans for tender.

Just to add to the above, depending on the detail/nature of the plan, an additional cost/sum needs to be allowed for work to the existing house to facilitate the proposed extension, it could be just as simple as allowing for making opes in an existing gable wall, and associated making good of existing finishes, to access the proposed extension or can be more complex (depending on the plan).

 

[David_Dublin]

I know that feeling!

Now we're suckin' diesel! Sounds like a big enough build and a simple enough build to grab builders interest (i.e. you should get good/competitive pricing for a job of that size).

You seem to be sort of on the right track. I would start at E 1,000 / m.sq. for the build/basic builders finish, including probably bog standard interneal doors, PVC windows and external doors, basic electrics, basic plumbing and heating, etc., etc., and then work up from there adding in the peripherals like sanitary ware, floor finishes (tiles or timber flooring) and extra/over costs where you want a higher spec (like for example maybe alu-clad timber windows and external doors).

You could save yourself a bit of time and headache by maybe asking a QS to do a preliminary budget costing for you which would/should include your specific wishes/requirements. This might cost you E 250. Might be a worthwhile exercise? With that under your belt, then you could approach an architcet to flesh out the plans for tender.

Just to add to the above, depending on the detail/nature of the plan, an additional cost/sum needs to be allowed for work to the existing house to facilitate the proposed extension, it could be just as simple as allowing for making opes in an existing gable wall, and associated making good of existing finishes, to access the proposed extension or can be more complex (depending on the plan).

Thanks a million for this, you have hit the nail right on the spot. Yeah, I think we'll have to involve a QS sooner rather than later. I dont want to end up with a fertile image of how amazing everything will look, only to discover that it is completely unaffordable.