Feasibility of extending room over garage and roof options

littleboo

Hi all

I have a 1970’s detached house, a double garage extends from the front and the 4th bedroom is over the garage with a flat roof dormer. The flat roof is felted and we had that replaced probably about 16/17 years ago. Planning ahead, I wondering how this room can be improved, and from a roofing perspective, what options there are, assuming that at some point that will fail. I always think of flat roofs as being a liability which will eventually leak, but there seems to be a lot of flat roofed extensions going up, so presumably have a good life expectancy?

The room is approx. 3m wide x 2.4 deep internally and I’m thinking that it should be possible to extend that forward by a metre or so, to give an extra 3x1m and make the room more usable. It would also allow the window to be at a more normal height, currently its high because of the slope of the roof. I expect that the whole thing is poorly insulated. Is it relatively straightforward to extend?

For the roof, I think a pitched, tiled roof would be far more attractive, but presumably expensive and would need quite a big roof alteration. If I’m extending the room, then I need a new roof in some form.

I hoping for some advice on how I can explore this further do, I have no idea. What do I need first – a builder, a roofer, an architect? Would the existing structure be able to support the weight of a tiled roof? Are there are other options to consider make the dormer look less utilitarian?

I have drawn the side elevation, not to scale, to give an idea of what I’m thinking

Thanks in advance

FreeBear

My initial thought - If you are going to extend, you may as well go right up to the end of the garage wall and have a bigger internal space. The overall cost isn't going to be much more. The alternative is to have a balcony, but planning dept may object to the idea, as would any neighbours being overlooked.

Whilst a flat roof will typically have a life expectancy of 25 years or so, a proper tiled roof will last considerably longer. But, as you surmise, it does come with a weight penalty and extra cost. However, you can get hold of roofing sheets that emulate the look of tiles. But it probably wouldn't look right sitting next to your existing tiled roof.

The first step would be to see how much money you have available for the project. Then bounce a few ideas off an architect to see if/what can be done within the budget, and go from there.

Section62

littleboo said:

I hoping for some advice on how I can explore this further do, I have no idea. What do I need first – a builder, a roofer, an architect? Would the existing structure be able to support the weight of a tiled roof? Are there are other options to consider make the dormer look less utilitarian?

We'd need a few pictures of the existing building to be able to give any meaningful comments, other than it would be normal to start with an architect for a project of this potential complexity.

My initial reaction is that would probably be the most expensive 3sqm you'll ever buy.  I'd also guess there is a reason why they put the wall there rather than futher out.

Rosa_Damascena

FreeBear said:

My initial thought - If you are going to extend, you may as well go right up to the end of the garage wall and have a bigger internal space. The overall cost isn't going to be much more. The alternative is to have a balcony, but planning dept may object to the idea, as would any neighbours being overlooked.

Whilst a flat roof will typically have a life expectancy of 25 years or so, a proper tiled roof will last considerably longer. But, as you surmise, it does come with a weight penalty and extra cost. However, you can get hold of roofing sheets that emulate the look of tiles. But it probably wouldn't look right sitting next to your existing tiled roof.

The first step would be to see how much money you have available for the project. Then bounce a few ideas off an architect to see if/what can be done within the budget, and go from there.

Are they any good?

FreeBear

Rosa_Damascena said:

FreeBear said:

My initial thought - If you are going to extend, you may as well go right up to the end of the garage wall and have a bigger internal space. The overall cost isn't going to be much more. The alternative is to have a balcony, but planning dept may object to the idea, as would any neighbours being overlooked.

Whilst a flat roof will typically have a life expectancy of 25 years or so, a proper tiled roof will last considerably longer. But, as you surmise, it does come with a weight penalty and extra cost. However, you can get hold of roofing sheets that emulate the look of tiles. But it probably wouldn't look right sitting next to your existing tiled roof.

The first step would be to see how much money you have available for the project. Then bounce a few ideas off an architect to see if/what can be done within the budget, and go from there.

Are they any good?

Neighbour used them on his new garage. Doesn't look too bad, and he is happy with them. Certainly a huge step up in comparison to corrugated iron or cement sheet.

Done a bit of digging. A link to the roofing sheets used - https://www.metrotile.co.uk/tile-profile/bond/ - Available in a range of colours & styles (other brands out there).

Slinky

Could the existing extension be a timber framed extension cantilevered off the original building in some way? I'm just wondering if the footings for the garage are deep enough to take the weight of a tiled roof?  We had a 1970s house and had to demolish the garage and rebuild with deeper footings when we extended over the garage.