Getting it right through design

There are fundamental principals that apply to the design of a green roof, regardless of the proposed landscaping, location or climate. The specified solution must replicate nature within the build up and be able to support the vegetation.

The first step - What is the landscaping finish to look like?

The primary decision is the type of landscape required that best suits the rationale behind the development, whether it is an intensive, simple intensive, extensive or biodiversity roof. Whatever the landscape chosen, the plants will have some basic requirements to sustain them; nutrients, a balance between moisture and drainage to suit the vegetation, and aeration to the root systems.

The next step - Planning the green roof to meet the needs of the vegetation

Once the vegetation finish has been determined the structural and design considerations and green roof components can be proposed.

It is vital that the protection of the building’s fabric and in particular its waterproofing is considered in the green roof design. There is important information that the building’s structural engineer will require:

■□ The height of the green roof system build up.
■□ The maximum saturated load of the green roof.
■□ The sheer force the green roof will exert when on a pitched roof.
■□ Safe access for maintenance.

Use the left hand navigaton to learn about waterproofing and drainage, structural loading and wind uplift, green roof components, green roof configurations, perimeters and safe access, and irrigation and maintenance.