Only local materials or those that are easily acquired should be used in the landscape for both budget and sustainability considerations. Nevertheless, there are circumstances when a unique material or installation technique for a special feature and outdoor space warrants inclusion. Some materials require the mining and use of scarce resources in addition to being manufactured many miles away from where they are to be used. Materials appropriate for a warm climate often do not work as well in a colder climate that experiences extreme temperature swings, frost, and winter snow. Sustainability
As previously discussed in Chapter 3, every design proposal must consider its impact on the environment and should attempt to create a small footprint on the land. Specifying the right material for any given element or area of the design should evolve from a thorough knowledge of materials and not be limited to the designer’s personal preference. Additional consideration should also be given to the clients’ preference, compatibility with the architecture of the house, and regional appropriateness. Function
The appropriate material for a pavement, vertical surface, or overhead plane is partially dependent on when, how, and for how long the material is used. For example, gravel, rough cut stone, and naturally weathered wood are suitable for a rustic, unrefined, rugged landscape, whereas brick, cut stone, and metal are suggestive of a polished and urban setting. Regional Climate
The amount, frequency, and timing of sun exposure, precipitation, frost, and even wind should have a direct bearing on material choice. The general selection of materials during preliminary design and the refined selection during the preparation of the master plan should be based on (1) function, (2) form, (3) style/character, (4) regional climate, (5) sustainability, (6) budget, and (7) availability. Other materials recycle previously used materials and/or are derived from local sources. Budget/Maintenance
The client’s budget is a big factor in determining what materials are suitable for a landscape design. Style/Character
The style of the house and the intended character of the landscape should be considered before selecting materials. It is a waste of time to dream about expensive materials or devise elaborate patterns and construction methods if the client is on a tight budget.