Construction elements are the buildings structural parts (e.g. columns, floor plates, foundations) and interior elements (e.g. doors, partitions, ceilings and floor finishes). The technical brief mostly focuses on requirements for interior elements because these tend to have a direct relation to the usability of a room or space. For a museum, for example, is makes sense to formulate requirements concerning floor finishes to ensure that the floor can withstand heavy foot traffic and the loads of heavy artworks. Likewise, there may be requirements for the flexibility of walls, allowing different exhibition layouts without major costs or disruption to the museums operation. An example of a requirement concerning an external construction element is the requirement that the buildings facade should be graffiti proof or that the facade should not be climbable for security reasons. Requirements for floor finishesThis example shows the requirements for the floor finishes in an office project. Although these are very detailed, they are still performance-based and do not specify a particular solution (e.g. textile, rubber, vinyl).Standard floor finishDescription Floor finish to be used for all spaces that are intensively used by staff and visitors, unless stated otherwiseProperty ValueAnti-static Electrical resistance 2KV (cf. EN1815)Cleanability Common stains (e.g. from coffee spills) should be easily removable, without special cleaning tools/ materialsSustainability Materials should be recyclable and free of toxics (halogen, formaldehyde or PVC)Resilience 40% (cf. DIN 18032)Slip-resistance R9 (cf. DIN51130) Mechanical servicesMechanical services relate to the plumbing, piping and systems that deliver heating, cooling, water, air and gases in a building. As explained earlier, the technical brief should refrain from specifying these systems in detail, but it can be useful to formulate general system requirements regarding operational issues such as ease of maintenance, reliability or warranties. It may also be relevant to specify which mechanical services should be available at room level. Do some rooms have specific ventilation needs? Should a room have dedicated outlets for gases or liquids? In hospital buildings, for example, patient rooms need to be equipped with specific outlets for the provision of oxygen, medical air and purified water. For other building types, requirements will be simpler, but still of practical importance. A school art classroom, for example, may require hot and cold water outlets, an extra-large sink and a clay sink trap.Electrical servicesElectrical services concern the buildings systems for lighting, power supply, security, data and communications. As with the mechanical services, requirements can be formulated on the level of the system as a whole, and on the level of particular rooms. On a systems level, there may be requirements concerning the reliability or flexibility of systems. It is quite common, for example, to ask for an additional 25% 46