The practitioner must first identify the risks facing the building, including fire, water, and other natural elements, and assess the likelihood of their occurrence. The building must be secured without causing damaging, physical or aesthetic, to the historic fabric of the place. The architect or preservationist should be consulted about each component of the security plan. Next, the security expert must decide on necessary compromises to his plan, based on limitations placed by historic fabric, cost, and aesthetics. Each type of building, such as church, museum, or customer-oriented establishment, has its own unwritten rules of security. The key to success in security of historic buildings is flexibility -- in some cases, security and fire protection equipment is concealed, while in others, it may be better to install them out in the open. Sometimes, security experts must compromise standard procedures to meet conservation concerns. Psychological security tactics are used to subtly display to visitors the measures being taken at a certain historic building. Elaborate security systems, unacceptable in modern buildings; portable detection; and alternative types of protection all become the norm in the effort to protect America's heritage. The security practitioner working in this environment must know about available tools; protect the historic fabric; understand conservation and construction techniques; assess risk; and employ a mix of equipment, staffing, and psychological deterrents.