Software Tools
Radiance—Lighting Design Software
This daylight modeling tool is widely accepted in the lighting industry.
Web Tools
Cool Roof Rebate Database
This is a database for local utilities that offer rebates for cool roofs.
U.S. EPA, ENERGY STAR Roofing Products
This site provides solar reflectanceAlso known as albedo: the fraction of solar energy that is reflected by a surface on a scale of 0 to 1. Black paint has a solar reflectance of 0; white paint (titanium dioxide) has a solar reflectance of 1. The standard technique for its determination uses spectrophotometric measurements, with an integrating sphere to determine the reflectance at each wavelength. The average reflectance is then determined by an averaging process, using a standard solar spectrum, as documented by ASTM Standards E903 and E892 levels required to meet ENERGY STAR requirements for qualified roof products.
Lawrence Berkeley National Laboratory, Heat Island Group—Cool Roofs
This site offers a wealth of information about cool roof research and technology, including links to a cool roofing materials database.
Cool Roof Rating Council
This website includes a page where you can plug in the roofing type, color, and SRI and emittance values you're looking for, and it will provide a variety of products and manufactures who meet your criteria.
Organizations
Green Roofs for Healthy Cities
This nonprofit industry association consists of individuals and public and private organizations committed to developing a market for green roof infrastructure products and services across North America.
Penn State University, Center for Green Roof Research
The Center has the mission of demonstrating and promoting green roof research, education, and technology transfer in the Northeastern United States.
Technical Guides
Whole Building Design Guide, Extensive Green Roofs
This article by Charlie Miller, PE, details the features and benefits of constructing green roofs.
Sample Plan – Cool Roof
Option 1
The project shown in this sample plan complies with the requirement to have greater than 75% of the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. light-colored.
Samples
Product Cut Sheets
Option 1
Look to product cut sheets like these examples to find high SRI values, indicating roofing materials that comply with the credit requirements.
Roof Weighted Average Calculator
As described in the LEED Reference Guide, a weighted average calculation may be performed for buildings with multiple roof surfaces to demonstrate that the total roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. has an average SRI greater or equal to a baseline theoretical roof with 75% at an SRI of 78 and 25% at an SRI of 30. Use this spreadsheet (with sample calculation) to determine if your roof complies—and if not, what adjustments need to be made.
LEED Online Forms: CS-2009 SS
The following links take you to the public, informational versions of the dynamic LEED Online forms for each CS-2009 SS credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
- SSp1: Construction Activity Pollution Prevention
- SSc1: Site Selection
- SSc2: Dev. Density & Community Connectivity
- SSc3: Brownfield Redevelopment
- SSc4.1: Alt. Trans.—Public Trans. Access
- SSc5.2: Site Dev.: Maximize Open Space
- SSc6.1: Stormwater Design—Quantity Control
- SSc6.2: Stormwater Design—Quality Control
- SSc7.1: Heat Island Effect—Non-Roof
- SSc7.2: Heat Island Effect—Roof
- SSc8: Light Pollution Reduction
Version 3 forms:
- SSp1: Construction Activity Pollution Prevention
- SSc1: Site Selection
- SSc2: Dev. Density & Community Connectivity
- SSc3: Brownfield Redevelopment
- SSc4.1: Alt. Trans.—Public Trans. Access
- SSc4.2: Alt. Trans.—Bicycle Storage
- SSc4.3: Alt. Trans.—Low-Emitting Vehicles
- SSc4.4: Alt. Trans.—Parking Capacity
- SSc5.1: Site Dev.—Protect or Restore Habitat
- SSc5.2: Site Dev.: Maximize Open Space
- SSc6.1: Stormwater Design—Quantity Control
- SSc6.2: Stormwater Design—Quality Control
- SSc7.1: Heat Island Effect—Non-Roof
- SSc7.2: Heat Island Effect—Roof
- SSc8: Light Pollution Reduction
- SSc9: Tenant Guidelines
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions on these forms; for more information, visit LEED Online and click "Sample Forms Download."
Design Submittal
Documentation for this credit can be part of a Design Phase submittal.


Sloped roofs have different minimum SRI requirements because of the different angles at which the sun’s rays will hit the roof. For example, flat roofs receive more of the sun’s rays at direct angles, thus the SRI requirement for flat roofs is higher (i.e., for lighter material) than for sloped roofs. (See chart, from the 




83 Comments
green roof cover - ivy
Hello,
I'm working on a project which is considering to use the ivy as green cover.
My worries in considering this system as a green roof , consist of the definition of greenroof which is supposed to have a layer of soil.
At the same time I'm sure that our system can reduce heat island effectHeat island effect refers to the absorption of heat by hardscapes, such as dark, nonreflective pavement and buildings, and its radiation to surrounding areas. Other sources may include vehicle exhaust, air-conditioners, and street equipment. Reduced airflow because of tall buildings and narrow streets exacerbate the effect., bacause of heat absorbition through the leave.
Looking forward to having your advice.
How to define ‘Roof Area’
Hi,
I’m working on a C&S project and have a problem with defining the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. of the project. The project has parking underground and three floors of retail spaces. Above one part of the building there will be unenclosed parking spaces (2 floors in total) with roof parking. Does the roof parking of the parking tower need comply with the SRI requirements or can this area be excluded from the roof area?
The roof parking covers the unenclosed parking floors and could be excluded from the roof area according to “‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1.“ However the roof parking is also the roof of the retail spaces under the unenclosed parking floors and should be included in the roof area according to “Roof area is the area of the uppermost surface of the building which covers enclosed Gross Floor AreaGross floor area (based on ASHRAE definition) is the sum of the floor areas of the spaces within the building, including basements, mezzanine and intermediate‐floored tiers, and penthouses wi th headroom height of 7.5 ft (2.2 meters) or greater. Measurements m ust be taken from the exterior 39 faces of exterior walls OR from the centerline of walls separating buildings, OR (for LEED CI certifying spaces) from the centerline of walls separating spaces. Excludes non‐en closed (or non‐enclosable) roofed‐over areas such as exterior covered walkways, porches, terraces or steps, roof overhangs, and similar features. Excludes air shafts, pipe trenches, and chimneys. Excludes floor area dedicated to the parking and circulation of motor vehicles. ( Note that while excluded features may not be part of the gross floor area, and therefore technically not a part of the LEED project building, they may still be required to be a part of the overall LEED project and subject to MPRs, prerequisites, and credits.).”
Any ideas?
Thanks.
exempted area from SSc7.2
Hi all,
our office building has a roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. that consists of some functional, usable spaces. In detail this area will be used as playground for children and as chill out area for office's employees.
Could this areas be deducted from the total roof surface area ( as I do for mechanical equipment?).
Thanks.
Mario, I could see an argument being made for this, but in my opinion, no. It's very common to have functional space on roofs, but this is not mentioned in LEED as an excludable space, and I haven't seen this question come up before. Also, just as non-roof hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios., including pedestiran-oriented hardscape, is counted in the nonroof credit, it seems that space of this nature should be counted in the roof credit.
Thanks Tristan.
We have recently found a Leed InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. saying:
"Roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. that consists of functional, usable spaces- such as helipads, recreation courts, and areas covered by equipment, solar panels, and appurtenances- can be exempted from the roof calculations for SSc7.2. Projects are not eligible for SSc7.2 if the exempted spaces encompass the entire roof area. Applicable Internationally."
In my opinion, functional and usable spaces can be exempted, considering that a high SRI value makes the roof area impossible to use due to the glare. What's your opinion?
Mario, you are correct. I should have revisited that LI before posting my earlier response. I agree you can exclude the space.
Mechanical room covered by greenroof
By definition the mechanical room will be excluded from roof calculations. However, we are considering covering a mechanical room with a greenroof in order to apply for this credit.
The issue here is that space is so limited and we need to provide 3300 sqft in order to comply with SSc7.2 and SSc5.1 as well.
We ran out of space because, however if we covered a big mechanical room where hvac and elevators machinery are we will be able to comply with these two credits.
But we dont want to run into a review saying the greenroof at the machinery room will be excluced from calculations.
Does anybody have any experience of greenroof in machinery rooms being accepted in order to comply with credits regarding vegetated spaces?
Michael, it's hard for me to imagine there being a problem with this. Excluding appurenances is a way to simplify the credit calculations and ease the requirements. You are choosing to make things a bit harder for yourself to earn the credit. I would simply include this area in your roofing calculations.
Great to hear this opinion Tristan. If at the end we submit it this way and get a positive response from the reviewers we'll post the results on the forum.
Thank you!!
Weighted calculation - lower SRI value
Hello!
We have a project in which the client will install a roofing material with an SRI value of 70 (low slope: requirement-78) for 100% of the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1..
Can this be compliant with this credit, using the weighted calculation? Even though 100% of the roof has an SRI value lower than 78?
Thanks!!!
Rosamaria, run the calculations and find out! There is a calculator in the Doc Toolkit above.
Thanks, Tristan. Yes, running the calcs and using the formula, it passes.
But the question was more if this formula applies to a project where all the roof areas will have the same material with an SRI of 70 (when it should be 78), or does it apply only to projects where they have SEVERAL roof materials and one or some of them DO have SRIs higher than 78, and others don't?
Thanks! :)
Yes, it applies.
SRI values for marble
Has anybody had any experience documenting SRI values for marble? We have a few greenroofs that, as part of design, implement some white marble pebbles but I just havent had a clue about how to document SRI number.
The American Institute of Marble recomends, according to the Natural Stone Council, that any claim of stone being a high SRI product must be substantiated through professional material testing. They also provide a few natural stones SRI measured by the American Institute of Marble but they show an average of 60, you can find this document at this link:
http://www.marble-institute.com/pdfs/CaseStudy4_SolarReflectanceOfStone.pdf
I know testing material through and accredited facility is the obvious option but that would increase cost and it is really difficult that and investor will be willing to do this just a few pebbles.
Any idea of a source that can be used as a SRI documentation for white marble?
Thank you very much.
Michael—sorry, finding SRI values for specific cases like this can be tough. I don't know if a source for marble SRI.
Thank you Tristan. How come that the GBCI does not accept a white marble as a given SRI compliant material?
I'm thinking about not specifying this anymore since it does not help achieving the credit.
Michael, GBCI would accept white marble, as it would any other material with valid SRI values.
That's the thing Tristan, since no documentation exists for marble, then specifying marble at a rooftop (in a sky terrace application for example) will not help you anyhow to achieve the credit, even though white marble will for sure comply with SRI requirements like I said no documentation exist.
I think this should be reviews by USGBC.
Mike. You can always get the material tested. There are plenty of testing companies out there that do that. Of course that costs.
Someone posted a contact for a US based testing company here in the forum. I just can't find it right now.
In Europe : Fraunhofer Institut" in Stuttgart, Germany does SRI testing. They need a product sample to do that. They will also translate it into English for an extra fee. http://bit.ly/pHZG5Z
Thank you very much Susann.
Thank you Susann!
Do you have a contact person in Fraunhofer Institut by any chance that I could reach out?
High Rise Tower with pointed crown
I am working on a HR tower with "virtually" no roof. The upper most portion of the tower is converging to a very narrow; curved glazed concrete-framed structure with no flat roof. Does it contribute to credit SSc7.2 compliance?
Also, for credit SSc7.1; does vertical surfaces of the tower providing shade to adjacent hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. contribute to credit compliance; or it should be only horizontal shading surfaces?
Even if you have no flat roof at all, the steep-sloped roof does count too. See the graphic above. You will probably count from the point the vertical surface starts angling towards the top.
As for SS 7.1 you may want to ask you question there, so other LEEDUser can find the answer also.
Good luck with your project!
Roof or Non-roof?
Hi All,
We are working on a high-rise office project that will sit on top of an existing structure. The existing structure (5-storey retail building) has a larger footprint compared to the proposed building.
We included the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. of the existing building to our project boundary where proposed landscape vegetation will be placed.
Should the top most floor (roof level) of the existing structure be considered as roof or non-roof in relation to the proposed high-rise office building?
Mary Ann,
I would suggest taking a look at the AGMBC which you can find on LEEDuser here.
Mechanical equipment compartments as roof surface
Hi everyone,
I’m working on a project registered under LEED 2009 C&S Rating System. I understood that roof surface is a surface that covers usable interior space, defined as a space which is both conditioned and occupied. On my project’s roof, there are some mechanical equipment compartments which are enclosed but not conditioned and not occupied spacesOccupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space.. Does my roof surface final count must include the roof surface of those mechanical equipment compartments or are those exempt from the SSc7.2 credit calculation?
Thank you in advance!
It use to be a bit more like you describe it, depending the space being conditioned. But with the new definition of roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. the roof above your mechanical room will be included in the calculation, since it's enclosed gross square footageSum of the floor areas of the spaces within the building including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft or greater. It is measured from the exterior faces of exterior walls or from the centerline of walls separating buildings, but excluding covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, chimneys, roof overhangs, and similar features. of the building. However form my experience these mechanical rooms a lot of time are more like a enclosure to prevent direct exposure to rain. So those walls often times are lovers all around and no actual wall separating inside from outside. I think in this case I would excluded such an area form the calculation. I hope that helps.
I would consider it an area that need to be included, after all is an area that otherwise would be heating up and remember the intent of the credit is to avoid the heat island effectHeat island effect refers to the absorption of heat by hardscapes, such as dark, nonreflective pavement and buildings, and its radiation to surrounding areas. Other sources may include vehicle exhaust, air-conditioners, and street equipment. Reduced airflow because of tall buildings and narrow streets exacerbate the effect..
The only think I could possibly think that can be exluded from the roof of a mechanical room is insulation since it typically is not a comfort area.
Has anybody had any experience about incluidng mechanical room's roof as part of the SSc7.2 scope?
HVAC on a green roof calculation
Hello,
we are working on the project of a new commercial building where green roof is about 50 % of the whole roof.
There are some HVAC installations consisting of a mechanical part (located on the non green roof) and of a ductwork (located mostly above green roof and partially above non green roof).
How can we handle this situation? Should we deduct all the HVAC installations of the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. OR should we deduct the mechanical parts only? What do do with the ductworks above the green area?
We would prefer to deduct all the HVAC or to deduct mechanical parts only for reduction of a roof area. Is it correct?
Thanks for any advice.
Petr
You can deduct both the equipment and the duct work. see also the definition of roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1.: http://www.leeduser.com/credit/NC-2009/SSc7.2#comment-16498
In many countries you are required to have gravel strips around and under equipment for fire security and people safety reasons. Even thought I don't think that was the reason for excluding these areas.
Good luck with the project.
Awnings?
Are awnings part of roofs? My project has a large roof and then some metal awnings over entrances, do the tops of the awnings also need to comply with/be counted in the roof credit documentation?
You don't have to include the awnings since there don't cover an enclosed space see also this comment with the definition of a roof. http://www.leeduser.com/credit/NC-2009/SSc7.2#comment-16498
SSc7.2 Option 3
In my project I will achieve the requirements of SSc7.2 with option 3. The roof is covert by 10% green roof and 60% white gravel and ….. My question is if I don’t get the SRI value from the manufacture of the gravel can I use the value of 79 from the LEED reference guide for calculation?
The SRI can vary a lot depending on, what exactly your gravel looks like and is made of. You will need the actual SRI either per manufacturer's data or testing. See also George's question below.
Pool SRI
Hi
What about a pool? In this project we are working on, there will be a pool in a terrace on the roof. What would it be it's SRI? Or does it depends on the tiling used under water?
Luis, this gets into some tricky issues which have been discussed in more detail on the NC version of the SSc7.2 forum, but my recommendation is to not try to count the pool for your SRI-compliant surfaces.
Solar cells and green roof
Hi
My project is having green roof (less than 50 % of the total roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. though) and the rest of the roof area will be covered of solar cells. Can I somehow use this toward this credti?
For this credit, according to Leed Online, you have to consider total roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. excluding mechanical equipment, photovoltaic panels and skylights. If your project's roof consist of only photovoltaic panels and green roof, in terms of this credit, 100% of this roof is a green roof and therefore you achieve it. Actually you can apply for exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. with this percentage.
The project i'm looking at has a green roof with PVs sitting on a framing system slightly above the vegetative material. Is it possible to include the plan view area of PV in the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. calculations as on other projects we've seen a better growing result in the shade of the PV than elsewhere . Sun angles etc would also mean that the green area is alos doing its job. The project's ecologist has given the all clear for walk on access for maintenance purposes. thanks
Vivian,
do you have other materials on the roof as well? Or is it only green roof with PV panels? If there is only vegetated surface and PV panels, why do you want to include it?
The reason for excluding mechanical equipment and PV panels from this credit calculation is that it would be contraproductive. HVAC systems are very often situated on the roof, because it is not possible to put it anywhere else. And without it you wouldn't achieve some other more relevant credits...
Yes there are other roof areas - two difference types of roof material and also some other plant enclosures. I'd exclude the plant areas easily enough but if we can include the area of PV within the green roof area on which the PV sits the calculations should be favourable for the 50% vegetative roof area
I see... my guess is that if you wish to do it this way, you will need to submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide on this.
SSc7.2 Inquiry - Subterranean 'Roof'
Hello,
The project I am working on consists of a tower with subterranean spaces that lie beyond the tower's footprint. Could we consider the vegetated area over the subterranean as "roof" and include it in the calculations for SSc7.2? Thoughts?
Thanks!
Patrick, I would say that depends in part on the function of the underground spaces. Are they conditioned and occupied?
Hi guys.
We have it the same, but on the contrarary. My guess is that if the underground floors serve as a garage, then the "roof" at the ground level can be considered a terrain instead of a roof and we do not have to count that towards achieving SSc7.2. Any comments on this?
Yet I forgot to mention that besides the green "roof" aka vegetated surface above garage there is a portion of asphalt drive way. That is why we want to exclude it.
Yes they are, both conditioned and occupied.
Patrick, in that case I would consider it a roof.
Existing White Roof
We are working on a Core & Shell major renovation which has an existing white roof. I've been having a hard time finding if we can just leave this roof and achieve this credit. Also, if we can achieve it do we need to count the materials for our total materials cost even though it's already in place?
Courtney, as with other existing materials on the project, you would not have to include the roof in your project cost. You could earn the credit by leaving the white roof in place, but you'll have to show that it has compliant SRI value. That will probably require finding specs from the manufacturer, or testing.
Skylight with Fins
Dear all,
My project is a retail mall with a very big skylight across the mall's width.
The skylight has alternating horizontal fins made of 19mm thick mild steel, meaning that one half of the skylight's area is going to be glazed and the other half is going to be white-painted steel.
Do I have to demonstrate SRI compliance for the glazing and the metal sheets of the skylight?
Thanks!
George, skylights are excluded from the calculations for this credit. I think that puts these fins, which you describe as an appurtenanceAn appurtenance is any built-in, nonstructural portion of a roof system, such as skylights, ventilators, mechanical equipment, partitions, and solar energy panels. on the skylight, in a bit of a gray area. Sounds like it would be a good idea to include them, though.
Using Table 1 of the LEED Reference Guide
Dear all,
It is being really hard to obtain Manufacturer data for the roof materials SRI in my country.
There is a table in the LEED Reference Guide that lists the "Solar ReflectanceAlso known as albedo: the fraction of solar energy that is reflected by a surface on a scale of 0 to 1. Black paint has a solar reflectance of 0; white paint (titanium dioxide) has a solar reflectance of 1. The standard technique for its determination uses spectrophotometric measurements, with an integrating sphere to determine the reflectance at each wavelength. The average reflectance is then determined by an averaging process, using a standard solar spectrum, as documented by ASTM Standards E903 and E892 Index (SRI) for Typical Roofing Materials". Is there any possible way that I can use this table in my calculations by any chance?
Thanks!
We have had the same issue on our projects. There are no SRI values for roofing materials and the only way of getting them is to perform an rather expensive testing. As far as I know and have read so far you will have to prove the actual SRI. You can not use that table. We haven't actually tried a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide or submitted the credit with presume values. So maybe they will except it, but my guess is not.
I would second what Susann says. You have to show actual SRI. I think part of the hope of LEED in general and perhaps in this credit is that manufacturers will be more motivated to provide this kind of information.
In this project, the gravel or cement on the roof is going to be painted white. The white paint is produced locally by manufacturers who do not know what SRI means!
As such, can I use the SRI value for the white coating in Table 1? I do not think that the SRI will vary significantly among white coatings.
Any suggestions?
Thanks!
Again, I think you need to use actual values, not rely on the table. The value for something that appears "white" can in fact vary a lot, especially when it's applied to something like roof ballast.
Does GBCI want to document SRI of materials that have SRI lower than required by this credit as well as of complying materials?
For example, part of roof is covered with bituminous material and part of roof covers high albedoAlbedo is synonymous with solar reflectance. EPDM foil. We have documents only for EPDM foil. In calculations for this credit I intent to use actual SRI for EPDM and for bitumin a value from the table or other sources. Could this be acceptable? Obviously, bitumins do not have high albedoAlso known as solar reflectance: the fraction of solar energy that is reflected by a surface on a scale of 0 to 1. Black paint has a solar reflectance of 0; white paint (titanium dioxide) has a solar reflectance of 1. The standard technique for its determination uses spectrophotometric measurements, with an integrating sphere to determine the reflectance at each wavelength. The average reflectance is then determined by an averaging process, using a standard solar spectrum, as documented by ASTM Standards E903 and E892 so the manufacturer doesn't even want to test the material for SRI. This sounds logical to me...
Petr, you do not need to document SRI for materials that you are not using to comply with the credit. I hope that answers your question.
I have the same problem in Brazil. Difficulties to obtain SRI value for some materials. One of most respected tech institutes performs SRI test according to ASTMVoluntary standards development organization which creates source technical standards for materials, products, systems, and services E 1980. However, the refletance value is obtained by ANSI/ASHRAE 74-1988 - "Method of Measuring Solar-Optical Proprerties of Materials - E procedure". Emittance is measured according to ASTM C1371, as indicated by the LEED RG.
Can USGBC/GBCI accept SRI values for a material performed in accordance with these standards referenced, using ANSI/ASHRAE Standard, instead of ASTM standard, to determine the reflectance value?
We have not submmited any CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide or LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org..
The reference Guide page 119, see footnote 2, listes both ASTMVoluntary standards development organization which creates source technical standards for materials, products, systems, and services 1980 and ASTM c1371. So you should be fine. No CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide necessary.
Reference Guide CS 2.0 says on page 105: "Default values will be available in LEED-CS v2.0 Reference Guide". I assume this points on the table on page 107. Under the table there is a statement that the values dont replace values of manufacturer data sheet. Strange for me? As we use white coatet gravel on built-up roofA roof covering consisting of several successive layers (each of which is called a "ply"), usually of roofing felt, with mopping of hot asphalt between layers and topped by a mineral-surfaced layer or by gravel embedded in a heavy coat of asphalt. and white cement tiles I would take the values from the table...
For documentation the RG says just to provide a list of materials of the SRI, but not how to proof this SRI. So I assume that they dont need manufacturer data sheets as proof, right?
You will need the manufacturer data sheets or testing protocols showing the SRI. You really can not use data listed in the table of sample data you may find otherwise. Also make sure the manufacturer list the standard under which he has tested the SRI.
Sorry, I know this is hard and expensive if you are working on a non US project. Good luck!
Roof area used as playground for elementary and pre-schoolschool
In a school project, we are using a great deal of the roof areaRoof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). ‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1. as play space for the kids. This area will have an appropriate surface for play and will not meet the urban heat islandA densely populated area in which pavement and buildings absorb, store, and release solar energy, making the vicinity warmer than it would be if the pavement and buildings were not present. SRI requirements for a roof. We are trying to figure how to count this space. Would it be considered roof? Would it be considered pedestrian oriented hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. ? If considered pedestrian oriented hardscape, could it count toward SSc5.2? Or can it be ignored completely since it is a roof area used as an occupied space? The latter would work well for us with regard to SSc7.2 as the remaining roof area is mostly white or vegetated.
Looking forward to your thoughts.
I think you would most likely have to consider this a roof, since it is a horizontal exterior surface over conditioned space. So, I think you would have to count it under SSc7.2. I suppose you could try to to count it under SSc7.1, under the argument that it's more like a non-roof surface, if you thought that would be advantageous, although you'd have to get a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide or hope for the best during review. I certainly couldn't see it being ignored—not clear how you could argue that. If it's occupied space that it would have to have roof above it, right?
I could see it being counted as pedestrian-oriented hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. under SSc5.2 if you're also earning SSc2.
Thoughts?
We are having the same problem on a football arena. The project has a big area which serves as roof for part of the occupied areas and is the main access of the stadium, functioning as a large circulation area. However, if we specify a material finish with a high SRI, wouldn't it be unconfortable for the pedestrians since it is a horizontal surface? If we specify an 29 SRI wouldn't it be enough?
Thank in advance for your answer.
Any of these surfaces over conditioned space would be considered a roof and would need to meet the SRI requirements accordingly. Although use of roof space for these activities is clearly commendable -- in may receive credit in other areas of LEED -- a dark surface would not meet the intent of this credit. Note that roof covering occupied but not conditioned spaces are not counted in this calculation.
I would not rule out a pedestrian-appropriate high SRI surface -- a lot of products have been developed in the last few years that meet the SRI requirements without feeling highly reflective. The stadium condition is somewhat unusual, though, so I don't know offhand of anything appropriate. You won't likely find products for the play space.
Definition of Roof
I am working on a project consisting of a horinzontal base building on which two residential towers are located.
My question is if the top of the base building counts as a roof to be included in the credit evaluation?
The intenden use of this area is as a recreational space for the apartments, so it is more like a terrace than a roofgarden.
with thank in advance for your answer
Robert, I believe that a roof is defined as a surface that covers usable interior space. So, for example, a balcony is not a roof, but it sounds like this terrace is a roof.
What about a terrace that is just partially covered by the next floor? One of the projects we are currently working on has this very interesting design: like stacked floors with some with vegetated terraces/balconies, and the next floor overhung partially or completely or opened like a rooftop terrace.
According to your experience, how shall we treat for SSc7.2 the terraces, that are partially covered by the next floor? I am thinking of counting as roof, only the visible part from bird-eye.
Also, a big issue is the open space calcs in SSc5.2: can we included the vegetated balconies, even though they are covered by the next floor.
Any thoughts and considerations would be highly appreciated. Thanks in advance.
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