Twin Pitched Roof, to single hip for loft conversion.

[Bewdy]

I'm looking at a property which is currently split into two flats and I'm wondering about the viability of adding another storey and potentially a whole extra flat in the roof space.

At the moment, as you can see from the attached pic (bottom one), there is a substantial twin pitched roof. I'm thinking of continuing the side with the two chimneys along, getting rid of the valley, and putting a flat roof at the top with some form of flat roof light, then dormers on the front and back.

I haven't inspected the roof structure inside yet, but assuming it's a traditional roof based on the age of the property, what's likely to be involved with getting rid of the valley, am I likely to be looking at replacing some (or all) of the roof with a steel structure, as in this link?

Also what's the possibility of being able to complete all this with the ground floor flat occupied, I'm guessing some kind of complete scaffold with a covering over the top? are they prohibitively expensive?

 

[noseall]

I can't comment on the structural side of things other than the push from the two remaining hip ends can only be dealt with via some serious invasive structural work, should you need to open up the whole space.

Large canopy scaffolds are costly. Upwards of £5k for an average detached house. A fair bit more for yours.