Nigel Mykura via Wikimedia / CC BY-SA 2.0

When choosing materials and construction techniques for a structure, consider how long you need the structure to last and how intensively it is going to be used.

Is the structure:

• going to be used constantly, for example steps in a public park?
• exposed to extreme weather, for example a bench in a coastal garden?
• going to come under heavy pressure, for example a driveway?

Different materials have different strengths, some will wear away or rot over time like wood, others are more likely to break or smash, like glass or thin concrete or stone slabs.

The following qualities of a material affect its performance:

• Mass and density – how heavy is it? How solid is it?
• Durability – how long will it last before wearing down or rotting away?
• Tensile and compressive strength – will it bend or crush?