5th floor...maybe a hobby room. E.g. stargazing with telescope. Ideal if the 5th floor in building contained a patio...no roof...the patio is the roof for the lower stories.

I would suggest you to cover some part or whole of the terrace floor with artificial grass. It stays green all year round and is also very easy to maintain as compared to natural grass. However, leave the place where you plan to install BBQ basin as it may get damaged because of fire. You can even place a swinger and 1 or 2 garden table set.

Warlike Tiger, Good Morning. Whats your dilemma. Is it the budget, design plan or availability of a professional to do it? Either of that would require a site study, without that it is not possible to estimate the plans or costs or even a realistic design plan. If you are keen , you can search for professionals in this forum and contact them or leave your number for interested architects to call you. However, this idea of building the second story and then breaking the lower floor walls is not feasible. It is a hilly area and you should be all the more cautious with the foundation. Hope this helps! Amit CORNERSTONE DESIGNS Bangalore.

This photo has taken from the rare side and as u can see the two polls and the wires.