Ideally, a standard data center architecture would be selected, and a building constructed to fit the modular components. However, this is often not possible. In most data center projects, existing buildings impose constraints, such as limited IT space, central chiller systems, electrical services, or headroom. For modular architecture to work in these situations, it must adapt to these restrictions. Additionally, data center operators may have specific design preferences. These could include requirements for guest tours, caging of equipment, or cabling setups that affect airflow or power distribution. Organizations may also have internal standards that influence the design. While modular architectures offer some flexibility to accommodate common preferences and constraints, extensive customizations could reduce the benefits of a standardized approach. > Design concept: A better result is achieved when the site specific preferences and constraints are reviewed and adjusted to suit a desired architecture, rather than to attempt to force an architecture into a pre-conceived specification. The most common constraint of a data center is the size and shape of a pre-existing room(s), and a practical modular data center architecture will have a method to accommodate variations in room size and shape.