A real estate developer builds on land, thereby increasing its value. The developer may be an individual, but is often a partnership or a corporation.
Developers are extremely concerned with providing useful buildings and structures. Useless buildings have no value, which means they can't be sold or rented. However, the building can only sell if it's in the right location, has utilities (defined as the availability from adjacent public roadways and with a sufficient capacity of water, sanitary sewer, storm sewer, electrical power, natural gas, telephone and cable) construction costs can be managed, and the project completes on time. The standard solution to the construction problems is to retain a registered professional engineer who specializes in supervision of construction, and involve this person before purchasing the land. The standard solution to the salability problems is to retain an architect to design an attractive development. Many developers retain ownership of profitable rental properties.