Many of the restrictions encountered in building design are imposed by legal regulations. While all must be met, those in building codes are the most signiﬁcant because they affect almost every part of a building.
Building codes are established under the police powers of a state to protect the health, welfare, and safety of communities. A code is administered by a building ofﬁcial of the municipality or state that adopts it by legislation. Development of a local code may be guided by a model code, such as those promulgated by the International Conference of Building Ofﬁcials, Inc., Building Ofﬁcials and Code Administrators International, Inc., and Southern Building Code Congress International,Inc.
In general, building-code requirements are the minimum needed for public protection. Design of a building must satisfy these requirements. Often, however, architects and engineers must design more conservatively, to meet the client’s needs, produce a more efﬁcient building system, or take into account conditions not covered fully by code provisions.
Construction drawings for a building should be submitted to the building-code administrator before construction starts. If the building will meet code requirements, the administrator issues a building permit, on receipt of which the contractor may commence building. During construction, the administrator sends inspectors periodically to inspect the work. If they discover a violation, they may issue an order to remove it or they may halt construction, depending on the seriousness of the violation. On completion of construction, if the work conforms to code requirements, the administrator issues to the owner a certiﬁcate of occupancy.
Forms of Codes. Codes often are classiﬁed as speciﬁcations type or performance type. A speciﬁcation-type code names speciﬁc materials for speciﬁc uses and speciﬁes minimum or maximum dimensions, for example, ‘‘a brick wall may not be less than 6 in thick.’’ A performance-type code, in contrast, speciﬁes required performance of a construction but leaves materials, methods, and dimensions for the designers to choose. Performance-type codes are generally preferred, because they give designers greater design freedom in meeting clients’ needs, while satisfying the intent of the code. Most codes, however, are neither strictly speciﬁcations nor performance type but rather a mixture of the two. The reason for this is that insufﬁcient information is currently available for preparation of an entire enforceable performance code.
The organization of building codes varies with locality. Generally, however, they consist of two parts, one dealing with administration and enforcement and the other specifying requirements for design and construction in detail.
Part 1 usually covers licenses, permits, fees, certiﬁcates of occupancy, safety, projections beyond street lines, alterations, maintenance, applications, approval of drawings, stop-work orders, and posting of buildings to indicate permissible live loads and occupant loads.
Part 2 gives requirements for structural components, lighting, HVAC, plumbing, gas piping and ﬁxtures, elevators and escalators, electrical distribution, stairs, corridors, walls, doors, and windows. This part also deﬁnes and sets limits on occupancy and construction-type classiﬁcations. In addition, the second part contains provisions for safety of public and property during construction operations and for ﬁre protection and means of egress after the building is occupied.