These instructions are using only parts from 10255 Assembly Square set. You don’t need any spare parts from the original set. You will get light and dark version of the handcrafted instructions in PDF and bricklink list in XML.
The building consists of three floors and it is divided into blue and green parts. Blue part contains gym and apartments and green part contains stairs. It can be placed next to the Police Station 10278 set.
On the first floor there is a public gym which can be used also as amenity for two apartments for bodybuilders. There is bench press, holder for weights, water dispenser, cash register and bathroom with toilet and shower. In front of a building is ice cream stand which will test the will of customers.
On the second floor there is blue apartment with small kitchen, table, holder for weights and modern bed with night table.
On the third floor there is very similar apartment which is more in dark red color. The bed has different design.
Roof is also divided into two parts. Roof over the blue part of the building is more ornamental. Roof over the green part is kind of black mansard roof.
Instructions are handcrafted in Studio 2.0 with all details and proper views of the build. You should be able to build this modular building without any issues. Please let me know via private message if something will not be clear. I will try to help you.
Enjoy the build!