Extensions - single storey with prep for second storey?

QTPie

Just wondering, can this be done?

Has anyone extended their house single storey with all preparation for a second storey extension at a later date (flat roof initially, then pitched roof later on). Or is the "cost saving" generally not too much (on about a 24m2 footprint)?

RJS86

It sounds like a sensible idea to me. When I removed the central load bearing wall, dividing the living room and dinning room in my house, I made sure it had capacity for a loft conversion in the future.

The main issue with your situation would be the foundations, make sure they have the capacity for the future development as that will most likely be the most expensive thing to alter at a later date. I would also consider the construction of the walls to ensure that the first floor walls can be easily built off it in the future. With that in mind I wouldn't leave it too long between phases as the Building Regs could update and increase cavity size requirement and cause complications. I'd consider using a solid wall construction with external insulation so that any future increases in U-value requirements would only effect the external face and not the wall itself.

macka0

It may be worth building the double but not knocking thru upstairs if money is an issue till you have got it,only one set of plans,not putting a flat roof on to rip off etc , might be worth pricing it up

mummyroysof3

It should be possible but tbh I would think it would be easier to do it in one go as I don't see the point in putting a roof on to then take it off to build second story. Will it mean you need plans done twice? Planning permission twice? And building reg hassles. We are looking into extensions but only need a bedroom but to do it will have too much downstairs space lol

a&akay

Did it DIY, but 26 years ago now. As others have said make sure the foundations are designed to take the second storey. I made the wall a parapet one so the 2nd storey could be built just by taking the capping stones off with the flat roof still in situ. I had the pitched roof extended and incoporated an attic and bathroom at the same time, builders this time as I wasn't into full blown pitched roof work. Extension was 25' by 13'.

Mojisola

macka0 wrote: »

It may be worth building the double but not knocking thru upstairs if money is an issue till you have got it,only one set of plans,not putting a flat roof on to rip off etc , might be worth pricing it up

Friends did it this way - the builder said it would be much cheaper than adding a second story later on.

It took a couple of years before the second storey was fully functioning but there was only one lot of major building mess to cope with.

QTPie

Thank you very much for these opinions/advice/experience - good to see what has actually been done before.

Am going to look at a house tomorrow - which would hugely benefit from a two storey extension - so will bare this in mind whilst looking around.