One of the main drivers of the design brief is to include more bedrooms. I think upstairs is probably the best place for the new bedrooms. Looking at the downstairs floor plan, one of the most obvious things to do at first glance is to build on top of the garages. Well what I mean by that is the two original garages immediately either side of the main 3 bay design of the house. We decide to engage a structural engineer to come and take a look at the foundations and it's good news. They're deep and strong enough to take a second level.
The other thing to consider is the quality of the space. The rooms created would be just under 3m x 3m (approx 9ft x 9ft) which would be very tight for a double bedroom. So this means this space could be used for a small bedroom or perhaps bathroom or dressing room depending on how the internal layout turns out.