Green roofs are roofs covered with vegetation that provide insulation and environmental benefits. There are three main types - intensive, semi-intensive, and extensive. Intensive green roofs support trees and require regular maintenance, while extensive green roofs use shallow soil and low-maintenance plants. Constructing an extensive green roof involves installing a waterproof membrane, turf hooks, edging boards, and a thin layer of soil and plants.

1. Green Roofs Defining green roofs Why use green roofs? Types of green roofs Construction methods Examples of green roofs

2. Defining Green Roofs Different definitions but simplest of them being: A roof of a structure that is covered with vegetation of some nature that can range from trees to moss

3. Why use a green roof system Provide high degree of insulation so keep heat in and cold out. Therefore reduce heating costs. Example U.K use more energy keeping buildings cool in summer than warm in winter They retain between 60%-100% of rainfall. So reduces pressure on drainage systems reduce need for attenuation tanks Absorbs Co2 emissions.

4. Why use a green roof system: continued Reduce the effect now referred to as “urban heat island” as cities as generally warmer than country side. Other benefits include improved: Life span double that of traditional roofs quality of water Air quality amenities

5. 3 main types of Green roofs: first one is: Intensive green roofs: no limit to amount of plants or trees requires regular maintenance and access. Due to depth of substrate. Most expensive. Likely to be found at ground level or flat roofs like apartment blocks and appear like a park with paths, benches and even playgrounds One building contains 35,000 plants and 75 types

6. Intensive green roof: ACROS Fukuoka building in Fukuoka city Japan.

7. Semi-intensive green roofs This type is restricted to smaller shrubs and grasses. Substrate layer is not deep enough for trees. Access is required for this type but not as much as this is not designed for people. Maintenance is less than the previous example. It is also less expensive.

8. Semi-intensive green roof: Roof cover on Airport in Amsterdam

9. Extensive green roofs Substrate is very minimal about 15mm There is a limit on the types and amount of grass of plants used This type is the lightest, the cheapest, very little in maintenance. What is involved in maintenance? Using the Lawnmower to cut the grass??? These characteristics make it the most applicable to domestic dwellings. So I shall discuss this type in further detail

10. Extensive green roof: domestic dwelling

11. Methods of constructing an extensive pitched green roof Roof loads must be calculated ensuring roof is strong enough when soil is dry and saturated Begin with ply decking and timber up stands. Apply bitumen based roof felt and seal with waterproof mastic.

13. Methods of constructing an extensive pitched green roof Turf hooks are then screwed onto the roof structure Followed by front edging boards to retain the soil. The membrane is then laid down this is what provides the basis to which the soil grips onto and grows around. This also sealed at all joints.

14. Membrane being rolled out.

15. Methods of constructing an extensive pitched green roof: continued The soil matter can then be displaced over the roof. It will then be spread evenly over the roof surface. Finally the grass, plants or turf can be used over the soil. The green roof is then finished.

18. Houses that may be familiar with green roofs Gary Neville's proposed new house development. The teletubbies house.

19. Gary Neville’s proposed new house

20. Teletubbies House