House flat roof conversion

AXO201993

Hi, we're thinking of converting our unusually flat concrete roof to a tall pitched roof to accommodate 2 extra bedrooms & 2 dormas. As the concrete roof is very substantial we could get away with using it as is & then building a roof on top. The size of the roof is 8 meters by 6 meters. Is there a way to work out very roughly how much this would cost.

Thanks for any advice.

Section62

AXO201993 said:

Hi, we're thinking of converting our unusually flat concrete roof to a tall pitched roof to accommodate 2 extra bedrooms & 2 dormas. As the concrete roof is very substantial we could get away with using it as is & then building a roof on top. The size of the roof is 8 meters by 6 meters. Is there a way to work out very roughly how much this would cost.

Do you mean a flat reinforced concrete roof?  When was the property built, and is it a one-off, or part of an estate?

AXO201993

Hi it's a one off circa 1920/30's detached house with a good 8 inches of concrete (not sure if reinforced?)

Section62

AXO201993 said:

Hi it's a one off circa 1920/30's detached house with a good 8 inches of concrete (not sure if reinforced?)

Is there an opening where the stairs would go up, or is that something which would need to be made?

If the latter then you'll need to get a structural engineer involved at an earlier stage than might be normal.  The costs of the project will depend greatly on how the existing structure works, and how the alterations impact on it.

One-off concrete structures of that era can have all kinds of 'quirks' - rule of thumb cost estimates don't really apply in more complicated situations of that kind.

AXO201993

No opening as yet so yes your right about engineer, thanks.

plumb1_2

You will have to take core samples , and employ a structural engineer 

stuart45

AXO201993 said:

 (not sure if reinforced?)

I'd be worried if it isn't.

SootySweep1

Hi
Could I ask what style of house it is ?

My parents have a flat roof bungalow which has a reinforced concrete roof.

Jen

GDB2222

Build costs currently are very high, but ballpark figures are often taken in more normal times as £2000 per sq m. Your roof is 50 sq m.  

So, I would guess that your project would cost somewhere between £100k and £200k. Maybe.

I’m not sure how helpful that is, unless you were perhaps hoping for £20k, in which case I’d say you need to reconsider.