1.4 Structural Design

The Object of Structural Design

The requirements of the client and user may include the following:

• The structure should not collapse locally or overall
• It should not be so flexible that deformations under load are unsightly or alarming, or cause damage to the internal partitions and fixtures; neither should any movement due to live loads, such as wind, cause discomfort or alarm to the occupants/users.
• It should not require excessive repair or maintenance due to accidental overload or because of the action of weather.
• In the case of a building, the structure should be sufficiently fire resistant to, give the occupants time to escape, enable the fire brigade to fight the fire in safety, and to restrict the spread of fire to adjacent structures.
• The working life of the structure should be acceptable (generally varies between 10 and 120 years).

The designer should be conscious of the costs involved which include:

• Initial cost which includes fees, site preparation, cost of materials and construction.
• Maintenance costs, e.g. decoration and structural repair.
• Insurance chiefly against fire damage.
• Eventual demolition.