Sat, 18 Apr 2026 11:19:38 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=5540#Comment_5540 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=5540#Comment_5540 Sat, 11 Aug 2007 09:36:14 +0100 GBP-Keith https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=5575#Comment_5575 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=5575#Comment_5575 Sun, 12 Aug 2007 13:00:38 +0100 Mark Brinkley https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=5582#Comment_5582 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=5582#Comment_5582 Sun, 12 Aug 2007 18:30:11 +0100 GBP-Keith
I wonder if green (sedum), is more absorbent of heat on the colour spectrum than say red tiles or grey slates.

I am also also looking for any studies that examine whether a good depth of soil absorbed heat during the day and released it slowly during the night? Though thinking about it this might actually make things hotter rather than cooler.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=8569#Comment_8569 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=8569#Comment_8569 Mon, 29 Oct 2007 16:19:57 +0000 RMN
National Research Council of Canada (NRC) carried out an experiment in Ottawa. The experiment called for the division of a roof into two half. One half a typical flat roof the other with a 150mm growth medium. The results showed temperatures of over 70 degrees on the typical flat roof and 30 degrees on the green roof.

Other research has been carried out in America and Japan relating to green roofs. America tried the white covering but the results where not staggering as all it did was heat the surrounding area. Add to this that the American researchers also liked the added benefit that a green roof helps with air quality where as a white roof does not.

In relation to American research you could look up the Chicago experiment between the Cook County building and City hall. These two building are very similar and are only a short distance from each other.

City hall roof (Paved) 126 -130 degrees Fahrenheit
City Hall Roof (planted) 91 -119 degrees Fahrenheit
Cook County Roof (Black Tar) 169 degrees Fahrenheit

It is the evaporation of the moisture in the green roof that helps reduce the heat gain/ emission from the roof.

I trust this helps.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=12089#Comment_12089 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=12089#Comment_12089 Tue, 08 Jan 2008 15:19:34 +0000 greenbyname
It uses a great number of mathematical models to calculate it's data, and is incredibly detailed.

However, the conclusion drawn was that "green roofs [u]do not[/u] act as cooling devices but as insulation ones, reducing heat flux through the roof". Of more use to designers, the report contains a number of parameters to aid the design of green roofs, eg moisture content, soil density, leaf area index etc.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=12105#Comment_12105 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=550&Focus=12105#Comment_12105 Tue, 08 Jan 2008 19:28:00 +0000 James Norton
How deep is planted grass, I it the sort of thing used on the Brighton 'Diggers', Segal self build or deeper still...?

RE the heat island, my understanding concurs with 'RMN', an if its the evaporation, I would of though the grass would have a bigger effect...?

J]]>