A number of factors need to be taken into consideration when purchasing locks for commercial facilities: security requirements, ADA compliance, how often the lock will be used, and the type of room being secured. From the front door to the storage closets, each application requires careful consideration in lock selection.

Most commercial buildings, from warehouses to schools, rely on a mixture of lever locks, deadlocks and mortise locks. Each type of lock normally is available in standard, medium and heavy duty construction. Standard duty locks are suitable for privacy locks, patio locks, classrooms and storerooms. Medium duty locks are suitable for office doors, passageways and classrooms. Heavy duty locks are suitable for entry doors, apartments and offices. When choosing a lock, consider how secure the door needs to be--heavy duty locks provide more security than standard duty locks.

Study the lock construction to determine if it's going to do the job. For example, in choosing a heavy duty cylindrical lever lock, look for the following specifications: 1) Meets ANSI/BHMA A156.2, Series 4000, Grade 1 for key-in-lever locksets; 2) Allen-head screws are used on the inside levers to prevent vandalism; 3) Lever is free-wheeling when the outside lever is locked; 4) Meets requirements of the Americans with Disabilities Act of 1991; and 5) Cylinder assemblies are removable in case the lock ever needs to be rekeyed.

Decide if you can use a mortise lock or need to install a deadlock paired with a cylindrical lock. A mortise lock provides ease of entry since the lever will open the door after the top locking mechanism is unlocked. A deadlock/cylindrical lock combination requires unlocking both the deadlock and the lever lock but provides more security.

Consider having a special coating added to lock levers installed on doors leading to rooms containing hazardous materials. The rough sensation of the abrasive coating alerts anyone opening the door to the potential dangers on the other side.

Added security can be found in electrified door locks. The best locks offer either a "fail safe" or "fail secure' option. A fail safe latch bolt
can be operated by the lever from either side except when the outer lever is electrically locked, then neither lever opens the door. By contrast, on a fail secure lever the deadlock latch bolt can be operated by the inside lever at all times, only the outside lever is inoperable when the latch is electrically locked.

The best lock suppliers will offer locks for every need, including asylum locks, dormitory locks and closet locks. Expect to pay from $40 for a basic lock up to $300 for the most secure locks.