Single Story Extension + Attic Conversion

steve22

Im currently debating the idea of an extension to my house and I really don’t know where to begin.

The house is a 3 bed semi detached in Westmeath and my requirements are one more bedroom and one extra room downstairs that will more than likely have many uses including utility/storage and possibly a play room for the kids for a while.

I’m not too inclined to go for a two story extension to the rear so Im wondering is there a huge difference (financially really) between a two story extension and a one story extension plus attic conversion?
I haven’t really done my calculations but the downstairs extension would be in the region of 200sf and the attic conversion would be into one bedroom, but being a hipped roof might need some modification. I was thinking of putting in a separate utility room downstairs but I’m trying to keep costs to a minimum and assume a single room would be the best idea and I can add my own storage units eventually.

So… To those in the know and those who have experience in this area… is there any way I could find out a rough price for such a job. A 150 – 200sf single story extension to the rear and attic conversion with possible roof modification.

If I had an idea of price at least I'd know whether to pursue it further!!

muffler

First thing: if you are going for a standard hip roof over a one room extension then you wont get a room above that will comply with regs. Abandon the idea of a hipped roof if you are thinking of having a room in the attic area and maybe consider a 1.5 storey extension in order to achieve requirements in relation to ceiling heights etc.

You are going to have to access the new "upper room" from the first floor in any event so why not just build 2 storey?

steve22

muffler wrote: »

First thing: if you are going for a standard hip roof over a one room extension then you wont get a room above that will comply with regs. Abandon the idea of a hipped roof if you are thinking of having a room in the attic area and maybe consider a 1.5 storey extension in order to achieve requirements in relation to ceiling heights etc.

You are going to have to access the new "upper room" from the first floor in any event so why not just build 2 storey?

thanks for your reply.
Maybe i wasnt quite clear... what i'm considering is two separate projects really.

1. A single story extension to the rear of the house.
2. Main house attic conversion.

The reason i mention the hipped roof is the house has a hipped roof at the minute and i've read that its difficult to do much with the attic space unless you change the overall roof - maybe put a gable end on it?
would i need planning permission to make changes to the roof?

I thought about the two story extension alright but i'm not really sure how i could work it out to connect upstairs. theres not a whole lot of room and i just thought i'd use the space in the attic and limit the amount of changes/disruption to the main house.



EDIT - Just read over my original post there and it does sound like i'm thinking of converting the attic space in the extension rather than the main house.... sorry about that!!

muffler

Ah, thats a bit clearer now

First of all converting a hipped roof attic area isnt great value for money as you have lost quite a bit of floor area/head room on account of the hipped roof. You will also have to comply fully with all relevent fire regs for the conversion should you choose to go down that route. Quite a bit of disturbace involved also compared to building a higher extension.

Bear in mind that you will loose a bit of floor space on the first floor no matter which approach you take - either for the stairs to the attic or a hall out to a new room in a 1.5/2 storey extension.

Depending on the location of windows in an attic conversion you may need planning permission. Likewise, depending on size among other things you may also need PP for a rear extension.

A very, very rough guide for building a single storey extension would be in the region of €100/ft2. Converting the attic could be around €70 or more per sq. ft.

If for example you priced a single storey extension and got quotes in around the €100/ft2 mark you could then go back to the contractors with revised plans showing an additional floor above the single storey extension and Id be fairly sure that the additional costs for the upper room would kick in at maybe €60/ft2. max.

I'd advise you to get a local arch. tchn or arch. to have a look and come up with a couple of ideas and see how the pricing works out from that.

steve22

Thanks for the info muffler, it's a great help.

muffler wrote: »

I'd advise you to get a local arch. tchn or arch. to have a look and come up with a couple of ideas and see how the pricing works out from that.

I think this is probably the way to go. Get an few proper ideas drawn up for each option and take it to a few contractors at that stage to get an idea.