1 storey v 2 storey extension

Hi

I am searching to buy a house and have pinned it down to 2 houses which would require extensions.

The one I am really looking at has a side entrance. The street has a mix of single and 2 storey extensions. Obviously there is a lot more cost associated with a 2 storey extension but I was wondering at what factor.

you would still require a roof, so it would be a matter of joining the original hip roof, floor joists, flooring, extra foundations, extra brickwork and extra windows. I was thinking if I am doing a single storey then would it just be better to try for the 2 storey and would it roughly be to a factor of 1.5?

I was also thinking to save on costs for the time being as budget would be an issue of making the ground level a garage, utility and toilet and convert at a later stage and this would save on a shed.

What would your thoughts be? I know I am simplifying here.

Penn

There's a whole range of different factors to be considered aside from just construction cost.

- Would your extension require planning?
- How much work would be required to the existing first floor layout to get access to the new rooms at the back, or is it just a case of making the existing rooms at the back bigger?
- What is the existing roof construction? Easier to tie a new roof into a cut roof than a prefabricated truss roof
- If you extend two storey, how much will that limit the light and solar gain on the ground floor?
- How much space around do you have for scaffolding?

Yes, there is an economy of scale when it comes to building, as in twice the area doesn't always equate to twice the cost. But some of the other considerations might negate that cost saving. The most important aspect to consider first is, what are your actual needs? Do you need the first floor extension?

I did a single storey extension, although really i wanted a 2 storey one. Problems I faced were I didn't actually need an upstairs extension, it was more greed, and the whole layout of my upstairs would have to change, unless I just wanted to extend the back bedroom and bathroom (which, though not a bad idea as such, would be a bit overkill, I'd rather another room altogether).

What actually put me off going the 2 storey route was the need for planning permission. I wanted to blitz through it, cut corners where I felt I could, throw extra money at things i wanted to, change ideas, layout, etc. and just generally wing it and hope for the best. Probably tormented the builder but it was a good laugh and a great experience. With planning, it'd be very rigid, I believe, and i'd be waiting months for the planning to be approved, and I'm just too impatient.

Yeah dont think I really need it

Worried about the new regs now, having to bring up the whole house could be pricey

Gumbo

Deleted User wrote: »

Yeah dont think I really need it

Worried about the new regs now, having to bring up the whole house could be pricey

Read the regs properly.
Do t fall for the media news story spon that’s full of inaccuracies.

https://www.seai.ie/publications/TGD-L-2019-Dwellings_Energy-Show-2019-Presentation.pdf

Deleted User

Deleted User wrote: »

Hi

I am searching to buy a house and have pinned it down to 2 houses which would require extensions.

The one I am really looking at has a side entrance. The street has a mix of single and 2 storey extensions. Obviously there is a lot more cost associated with a 2 storey extension but I was wondering at what factor.

you would still require a roof, so it would be a matter of joining the original hip roof, floor joists, flooring, extra foundations, extra brickwork and extra windows. I was thinking if I am doing a single storey then would it just be better to try for the 2 storey and would it roughly be to a factor of 1.5?

I was also thinking to save on costs for the time being as budget would be an issue of making the ground level a garage, utility and toilet and convert at a later stage and this would save on a shed.

What would your thoughts be? I know I am simplifying here.

For what it's worth, bought a house that had a garage to the side that was structurally unsound. We had a choice of demolishing and extending as a single storey or demolishing and rebuilding as a two-storey.

We went with the two-storey at a cost of 72k as opposed to 49k for the single storey. We were gutting the entire house so going with the two-storey and gaining a master bedroom, en suite and walk in wardrobe was a no brainer.