House Extension - Structural Question

[ben123d]

Considering a two storey extension to enable us to have a bigger house bathroom. I've just got a couple of structural questions.

The project is the extend an existing two storey lean-to structure (original part of the house), effectively moving the end wall outwards to add an additional 1.5m in width (1.3m internal approx.) to the downstairs cloakroom and toilet, and upstairs bathroom. The wall between the downstairs toilet and cloakroom is just a partition (not load bearing)

I'm wondering if this is structurally possible? If so, does that mean a new floor joists in the existing rooms upstairs and down stairs? Or just a new roof as the perlin is resting on the wall to be moved?

Could this be done as a timber frame to cut time, costs etc. Very basic diagram below. Red area to be extended into to form larger bathroom. Blue fill box is the existing house. So an infill extension of sorts.

Any info or assistance would be much appreciated, and apologies in advance if I've not provided enough info and happy to supply more.

 

[cdbe]

Perfectly possible, my initial focus would be lower down - foundations and any drainage that might get in the way. A bit of steelwork upstairs isn't likely to be a big issue.

 

[ben123d]

There is a drain to be dug out and moved, but I don't think it's going to be too bad.

There is a basement under the ground floor too, which I should have mentioned. Not sure how that will impact foundations.

Out of interest, why would a steel be needed upstairs? Would that be in place of the perlin?

It's currently a vaulted ceiling upstairs, with nothing above.

 

[^woody^]

Anything is possible , but cost is normally the issue.

You would be better off posting up some elevations, as I for one can't make head or tail of the floor plans

 

[ben123d]

Apologies for the quality of the drawing. Not a gifted artist, so photos also attached. Looking to build out into that blue brick work for the extension to bring it flush with the building line

 

[cdbe]

the perlin is resting on the wall to be moved?

why would a steel be needed upstairs?

Possibly under the purlin when you take the wall out.

 

[ben123d]

I'd be quite interested to know if this could be done as a timber framed extension?

Like to retain the vaulted ceiling, as it makes the space lighter, especially with the velux

 

[^woody^]

It does seem straight forward structurally, but as always the drainage needs to be considered - more so in this case by the looks of things.

A timber frame would be possible, but the issue would be what it is clad with - there may be planning issues with appearance. If it will have a brick outer skin, I can't see any real advantage with a timber frame for such a small extension.

 

[ben123d]

It does seem straight forward structurally, but as always the drainage needs to be considered - more so in this case by the looks of things.

A timber frame would be possible, but the issue would be what it is clad with - there may be planning issues with appearance. If it will have a brick outer skin, I can't see any real advantage with a timber frame for such a small extension.

A house near-by did a similar extension and used stone harvested from the existing house (i.e. the infill section which would be covered by the new extension) as the outer leaf of the timber frame, and it looked pretty good.