Consider the following aspects when designing a floor plan: the purpose of the room (entertaining, working, sleeping), cost, your requirements and the needs of your family, traffic habits, comfort features, source of light, safety, wiring, plumbing, ventilation, room décor, furniture, and... the list goes on! A designer can help you consider all these factors so that you end up with a plan that meets your needs while still giving you freedom to change things around as your life changes. The main effect that the design of the floor plan has is determining how we use space. By deciding what functions we want our rooms to serve, we are able to create a plan that is efficient in its use of space. For example, if one of the goals in designing a bedroom is to give the illusion of more space by using smaller beds, then a loft or storage area for clothes or books is necessary. In contrast, if the goal is to make the most of the available space by using a large bed, then it isn't necessary to include a closet in the design. In addition to determining how we use space, the design of the floor plan affects other aspects of the house such as security, accessibility, and cost. If you require complete privacy in a particular room, for example, a walk-through wall may be required to ensure visitor compliance with building regulations. This would mean including a door with a lock on the inside of the room for extra security.