cost difference between 1 3/4 storey and 2 storey house

[Amateur bob]

im curious to know if there is much difference in build cost between a 1 3/4 storey and a 2 storey house? does the roof line having to be broken up add much of a cost to the 1 3/4 house? thanks

[ProDave]

I doubt there is much difference in cost.

 

If building 1 3/4 I would (I did) avoid conventional dormer windows.  I dislike the complication of them and some aspects of their detail can be very awkward to get right.  And they don't add that much space.

 

Instead I did "gable ends" like this:

 

 

With a vaulted roof hung from ridge beams, this gives a clean inside and outside, with standing headroom in all but the extreme corners of the bedrrooms.

 

 

 

[nod]

Not a lot 

That why there are so many of these 3 & 4 storey houses being built and so few bungalows 

A large part of your build is site excavation and drains 

We blew nearly a third of our total spend getting the slab and garage bases in and drains  

[nod]

3 minutes ago, ProDave said:

I doubt there is much difference in cost.

 

If building 1 3/4 I would (I did) avoid conventional dormer windows.  I dislike the complication of them and some aspects of their detail can be very awkward to get right.  And they don't add that much space.

 

Instead I did "gable ends" like this:

 

 

With a vaulted roof hung from ridge beams, this gives a clean inside and outside, with standing headroom in all but the extreme corners of the bedrrooms.

 

 

 

Nice 

Though I quite like those preformed chunks of fibreglass that most of the builders use ?

[the_r_sole]

.

Edited September 26, 2019 by the_r_sole

[Temp]

We have a 1.5  storey house. Only thing I would do differently is put more insulation in the roof pitches. We appear to have an issue with solar gain through the roof itself.

[ProDave]

Well looking logically these are how the costs go:

 

Additions: 

Extra cost of more complicated roof structure including more complicated roof tiling and valleys etc.

Extra time to insulate board and finish sloping ceiling details.

Extra cost of roof windows Vs ordinary windows.

 

Savings:

Less external wall to build and finish (render etc)

 

Other benefits:

Lower overall working height, good for self builders with a touch of vertigo.

 

The lower sales value is irrelevant here. Planning rules mean that 99.9% of houses in the countryside here are 1 1/2 storey so it is what people expect and considered "normal"

 

And if self building a lot of the extra costs are just a bit more of your time.  So I think it boils down to extra cost of more complicated roof structure Vs cost saving of not building 2 storey high walls.

[joe90]

Originally ours was to have skeilings (1 3/4 ?) but decided last minute to go full 2 story (kept ridge height the same so planners not involved) extra cost was bricks only (6 rows), builder said no extra cost on labour as saved faffing elsewhere.

[Amateur bob]

20 hours ago, ProDave said:

I doubt there is much difference in cost.

 

If building 1 3/4 I would (I did) avoid conventional dormer windows.  I dislike the complication of them and some aspects of their detail can be very awkward to get right.  And they don't add that much space.

 

Instead I did "gable ends" like this:

 

 

With a vaulted roof hung from ridge beams, this gives a clean inside and outside, with standing headroom in all but the extreme corners of the bedrrooms.

 

 

 

nice house what sq m is that in size? do you have a rough cost per m2 for the build? thanks!

[Amateur bob]

20 hours ago, nod said:

Not a lot 

That why there are so many of these 3 & 4 storey houses being built and so few bungalows 

A large part of your build is site excavation and drains 

We blew nearly a third of our total spend getting the slab and garage bases in and drains  

was it a sloping site?

[Amateur bob]

6 hours ago, Sensus said:

 

The  standard house type range at the last major developer I worked for was almost entirely 2 storey (we had a few 2.5 storey 5 beds), but we used to build a mix of 2 and 1.5 storey variants in my Region (Cotswolds), due to Planning requirements.

 

The QS's reckoned that as a rule of thumb, the additional work involved with a 1/2 storey upper floor (insulation/airtightness detailing; dormers; roof structure) increased the cost per square metre on that storey by 25%.

 

At the dame time, the Sales Director also reckoned that the sloping ceilings discounted the sales revenue - again for the square metreage on the upper floor, taken in isolation, and again as a rule of thumb - by 15%.

 

The total 'cost' was therefore 35% for the floor area of the upper floor.

 

Obviously, the economics will be different for self-builds.

so its 35% more expensive to build a 1 3/4 storey as opposed to 2?

[nod]

32 minutes ago, Amateur bob said:

was it a sloping site?

 

13 minutes ago, Sensus said:

No, it's roughly 25% more expensive to build the upper storey, and once complete you would value the floor area on that upper storey at  roughly 15% less than you would if it was full storey height.

 

Build costs and sales values per m² floor area for the ground floor remain unaffected, so the overall additional cost/reduction in sales value is somewhat less.

No ours was flat as a pancake 

Just lots of trees and deep foundations 

[Amateur bob]

2 hours ago, nod said:

 

No ours was flat as a pancake 

Just lots of trees and deep foundations 

A lot of roots then? whyd u make the foundations so deep?

[nod]

We never came across any roots 

We had 500 mil to take off the whole plot 1800 deep for strip foundation for house and garages due to the heave from the near by tree Clay board etc 

750 tons of much out At least the same back in 

The muck away cost 13 k

 

[ProDave]

4 hours ago, Amateur bob said:

nice house what sq m is that in size? do you have a rough cost per m2 for the build? thanks!

About 145 square metres, I forget exactly, depends if you count the integral garage or not and the roof space above it (plant room)

 

Hoping to complete for £1000 per square metre.

[nod]

We have recently completed 

For slightly over 800 per sq mtr 

5 bed 284 sq mtrs Not including land purchase 

Still some landscaping to do 

and lawn to put down 

 

 

Edited September 5, 2019 by nod
Add more pictures

[nod]

13 minutes ago, nod said:

We have recently completed 

For slightly over 800 per sq mtr 

5 bed 284 sq mtrs Not including land purchase 

Still some landscaping to do 

and lawn to put down 

 

 

 

[Amateur bob]

very impressive which timber frame company did you use? do much yourself?

[Amateur bob]

13 hours ago, ProDave said:

About 145 square metres, I forget exactly, depends if you count the integral garage or not and the roof space above it (plant room)

 

Hoping to complete for £1000 per square metre.

you must have done most of the build work yourself at that cost?

[ProDave]

Just now, Amateur bob said:

you must have done most of the build work yourself at that cost?

Yes. Needs must.

 

I paid a builder to lay the foundations and build and erect the frame.  After that I have employed a plasterer and a joiner for some detail work, and just about all the rest I have done myself.

 

Still not finished but I still hope to complete for that price.

[Amateur bob]

6 minutes ago, ProDave said:

Yes. Needs must.

 

I paid a builder to lay the foundations and build and erect the frame.  After that I have employed a plasterer and a joiner for some detail work, and just about all the rest I have done myself.

 

Still not finished but I still hope to complete for that price.

who was the frame company? what do you think of scotframe? i hear a lot about them but looked at frame costs on their website and they werent cheap

[ProDave]

10 minutes ago, Amateur bob said:

who was the frame company? what do you think of scotframe? i hear a lot about them but looked at frame costs on their website and they werent cheap

I had a lot of trouble finding anyone that would do what I wanted.  I wanted more insulation than a "standard" TF and I did not want the standard concrete block outer skin that adds almost nothing to the insulation.

 

I tried talking to Scotframe about using a standard frame and adding extra insulation to it, they refused to quote.

 

In the end it was designed by a local architectural engineer and detailed by a structural engineer and built to those drawings and erected by a local small building firm.