For security reasons, locking systems must be available in the door. These locking systems can be digital or manual. Manual door systems require a key to open the door from the outside. However, should a key be required to open the door from the inside? In author’s opinion, it shouldn’t be. However, most of the existing door lock systems require a key to open the door from the inside. This may leads some problems in emergencies. In the event of a fire, gas leak or other accidents in the building, tenants should leave the building immediately.

Therefore, the lock should have a button on the inside of the lock so that it can be opened easily (Figure 1). On the other hand, most of the access to the office or educational building is controlled by the specified security person. The security guards lock the building according to the preset time.

If a person is trapped in the building due to work outside of business hours or while using the washroom, or for any other reason, they cannot leave the building until security has opened the door. During this time, the trapped person is in trouble if an accident occurs in the building. There are many deaths in the world, for example in the event of a fire because there is no suitable exit system. The best option for the building door should be the push bar system. Figure 2 shows a typical push bar door exit system from the inside for commercial buildings.

In some countries, locking systems for commercial buildings should meet certain standards such as the Americans with Disabilities Act (ADA) and the Health Insurance Portability and Accountability Act (HIPAA). These regulations are intended to ensure that people with reduced mobility can safely exit the commercial buildings in an emergency. Hospitals and other important buildings should also follow the HIPAA regulations for increased security requirements.