On a multinational Team from design to construction it can take a minimum of 36-50 months. Yes time can be cut -- certainly not to 15 days -- but not with the way large developments are currently build. The average rate of floor construction (with a prestressed slab) is 4-7 days, so the absolute minimum time required to get just the structure going will be >57 weeks. The average rate to get a single bath tub approved by the Consultant, Engineer, Client, Finance etc., is normally 3 months. To get a Hotel room approved down to the last fitting, carpets, access systems, IPTV, media hub, lighting, air conditioning and everything co-ordinated is anybody's guess, but again not less than six months.
On the current Project we are just finishing (5 luxury hotels), we have over 100 km of steel piping just for fire protection and chilled water for the air conditioning systems. There are over 50 systems involved, such as data, IPTV, WI-Fi etc. At peak we had over 5000 people working on the Project.
No chance in hell that an up to standard hotel can be finished in 15 days.