Instructions
Build a lobby. Click on the lobby tool and drag a lobby out on the first floor. Don't make a lobby much wider than a screen length at the beginning; you can always add on later.
Build an elevator. Click on the elevator tool and click once on the lobby. Each elevator must originate in a lobby. Click on the arrow at the top of the elevator and drag upwards to extend the elevator skyward, creating more floors.
Create offices and condos to earn money and increase the population of your tower. Devote each floor entirely to either offices or condos; combining them will cause your condo tenants to complain about the office noise and move out. While offices are intially less economical to build, they provide the highest population density of any room available in SimTower.
Reach the two-star rating by achieving a population of 250 or higher. Create hotel rooms for extra income, and accompany these with housekeeping rooms for cleanliness.
Extend your lobby outward and build more office space. Extend the elevators to the basement level and build a few fast-food restaurants to feed the office workers. Build more elevators on your elevator shaft by clicking on the elevator tool and then clicking on the shaft. Only eight elevators are allowed per shaft.
Build a security center near the lobby. These may not be demolished and must be near a lobby. The security center is required for a three-star rating.
Watch your population increase to 1,000 people. With a security center already built, you will achieve a three-star rating after meeting the population requirement.