The use of microducts inside buildings provides several important benefits, the design can be customized to avoid installing distribution boxes every floor instead they can be installed every other floor or even further apart. It all depends of the specifics of the building, the outcome of the design you are looking for, the penetration and growth and the details of the boxes and equipment you are planning to use.
The cable riser of the building in below case it a 12 fiber cable installed inside the proposed Riser 12 way microduct using one of the empty 5/3.5 mm micro ducts. If your design requires to have a larger count fiber cable, then the configuration will be similar but having a larger in diameter microduct located in the center of the bundle that could be a 12/10 or even larger. Each apartment will be fed by an individual 5/3.5 mm microduct from one if the distribution boxes and depending on the design criteria a single fiber cable and up to a 12 fiber cable can be blown inside.
In the case of the example there are 8 apartments per floor, it means that the distribution boxes can be place every third floor and interconnected with the 12 way. In order to breakout to the floors above or below of each distribution box, in each box and also in each floor the pre-assigned 5/3.5 mm tubes can be accessed, then cut and connected to each individual 5/3.5 mm micro duct that are installed into each customer premises. The distribution boxes installed will contain the optical splitters that will distribute the bandwidth throughout the entire building. The fibers coming out of the splitters will run inside each 5/3.5mm tube and into the apartments.
By using this design you will only have fiber splices inside the distribution boxes where the optical splitters are and drop fibers can be blown from there directly to each apartment. Individual 5/3.5 mm is lot easier to conceal or camouflage as they are white and small.