Submerged Lands

The word biodiversity is used to describe the range of organisms inhabiting a particular ecosystem. The greater the diversity of organisms, the more healthy the ecosystem tends to be. Maintenance and encouragement of biodiversity is therefore a key part of the sustainability agenda. In order to maintain and improve biodiversity, developers should try to incorporate building elements that provide habitat for plants, birds and animals in and around the properties that they construct. In many countries, biodiversity is not an optional extra, but a requirement of the planning system with which property developers must comply with. The use of landscape architects with appropriate knowledge of techniques for the encouragement of biodiversity does not only help to achieve the goal of biodiversity, but can also make a development much more attractive, which generally enhances consumer demand.

One interesting way of introducing biodiversity to developments is through the provision of green and brown roofs. Green roofs can be either flat or pitched. Flat green roofs can be either intensive or extensive. Extensive roofs have a thinner layer of grass or sedum grown in a thin layer of matting or soil above further layers of materials that ensure both the viability of the overlying foliage and efficient drainage. Intensive roofs are similar in construction but have a deeper soil layer in which larger plants, including trees, can be grown. Intensive roofs are often used to provide amenity space to residents as well as contributing to biodiversity. Pitched roofs, which can only be extensive in design, require simpler waterproofing and drainage systems than flat roofs, because the formation of pools of water is prevented by their design. Some developments are now starting to introduce green walls, which operate on similar principles.

Brown roofs, also known as bio-diverse roofs or rubble roofs, are similar in design to flat green roofs, but are usually designed with specific biodiversity objectives in mind. They are typically planted with a much wider variety of plants than green roofs and the growing medium also tends to be more diverse. Soil and rubble are deposited in varying depths to suit different vegetation types. The extra weight generated by the use of rubble and an unequal distribution of weight requires such roofs to have greater structural strength than green roofs. Sometimes brown roofs only provide the growth media, which are then seeded by the wind, animals and birds. The planting of certain forms of vegetation can be used to encourage particular bird and animal species to frequent the area.

These roof types help to provide a more constant temperature for buildings. In the winter, they keep the heat in while in the summer they help to keep buildings cool. They can also enhance the appearance of buildings, although brown roofs can be less attractive to some people, and as mentioned above, can be used to provide amenity space for residents. They generally require little maintenance, although drainage systems may need repair and weeding may be required if aggressive, unwanted plants start to colonize them.

Reducing Energy Usage of New Developments
Reducing Water Usage of New Developments
You Are Here Encouraging Biodiversity on New Developments
Reducing Construction Waste
Becoming a Sustainable Business
ISO 14001 Accreditation