Leed Roof Sri

Emissivity is a material s ability to release absorbed energy.

Leed roof sri.

The intent is to provide a standard certification process that registers buildings constructed with environmental performance efficiency and occupant health and well being as primary goals. Cool roof coating products are available for most roof types according to the department of energy. To meet leed requirements a roofing material must have a sri of 29 or higher for steep slope 2 12 roofing and a sri value of 78 or higher for low slope roofing. Projects seeking leed v4 have the option of qualifying using either initial sri or by obtaining the 3 year aged sri value.

In the earlier leed 2009 requirements cool roofing did not consider aged sri as an option for qualification. Low sloped roofs those below 2 12 and flat roofs must have an average initial albedo of at least 0 65 and steep sloped roofs must have an average initial albedo of 0 25 or more. A steep sloped roof must have an initial sri of 39 or a three year aged sri of 32. Leed 2 2 sustainable sites credit 7 2 states that to receive one point building owners should use a roof with a solar reflective index sri of 78 over at least 75 percent of the roof s surface for roofs with slopes less than 2 12.

The requirement for sri can be met by using concrete rather than asphalt for 50 of all sidewalks parking lots drives and other impervious surfaces. The environmental protection agency s energy star roof product program www energystar gov has cool roofing specifications for both low sloped and sloped roofs. Recycled content of berridge metal. Any roof used to shade or cover parking must 1 have a three year aged sri of at least 32 if three year aged value information is not available use materials with an initial sri of at least 39 at installation 2 be a vegetated roof or 3 be covered by energy generation systems such as solar thermal collectors photovoltaics and wind turbines.

As shown in table 1 the minimum sri for cool roofing has increased in the newer leed v4. Under roof or under building. Sri measures the roof s ability to reject solar heat defined such that a standard black reflectance 0 05 emittance 0 90 is 0 and a standard white reflectance 0 80 emittance 0 90 is 100. This credit is worth 1 point.

For leed v4 in existing buildings low sloped roofs must have an initial sri of 82 or a three year aged sri of 64. Leadership in energy and environmental design leed is the green building rating system developed by the united states green building council usgbc. Concrete is typically the material of choice for parking structures. Green roofs and leed certification.