This credit is fairly straightforward and easy to achieve if you are newly creating all the hardscapes. You may comply by applying prescriptive design measures outlined by LEED to 50% of your site’s hardscape, or by covering 50% of your project's parking spaces.
There can be added costs and labor if your project needs to modify existing hardscapes to meet the prescriptive goals of the credit: for example, taking out a black asphalt parking lot to install a more reflective material.
When dealing with existing hardscapes, it may be more cost-effective to shade areas with trees or landscape features than to replace them. This credit can be unattainable if your project’s hardscapes do not already comply and you do not have control over the design of hardscapes.
Before working to treat the hardscape surfaces on your project site, don’t forget that the most effective way to reduce heat islands and help with this credit is to limit the amount of hardscape and parking spaces provided in the first place.
Open-grid pavingLimiting hardscape not only reduces the square footage you must treat with light-colored paving, shading, open-grid paving, or covering, it can also help you gain points under:
The “solar reflectance index” or SRI is the measure of a surface’s ability to reflect solar heat. Higher reflectivity is desirable, because it helps combat 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. effect. SRI can range from zero to over 100, with darker surfaces closer to zero and lighter surfaces approaching 100.
This credit is fairly straightforward to achieve: You may comply by applying prescriptive design measures outlined by LEED to 50% of your project site’s hardscape or by covering 50% of your project's parking spaces.
Surfaces absorb and emit varying degrees of heat based on color and material. The photo shows four adjacent surfaces at the same time on a summer day in Chicago. The new black asphalt has the highest temperature at 126 degrees, while the new white concrete is almost 20ºF less, at 108ºF. Image – YRG SustainabilityIf you need to modify existing hardscapes to meet the prescriptive goals of the credit, you can face added costs. For example, demo of a black asphalt parking lot to install a material with a lighter SRI would be an added expense compared with resurfacing the same asphalt. When dealing with existing hardscapes, it may be more cost-effective to shade areas with trees or landscape features than to replace the hardscapes with lighter SRI material.
Examine existing conditions to help guide site plan development. Does your existing site have shading from trees, covered parking, or light-colored hardscape? Are there ways to minimize your project site’s hardscape and parking areas (including gravel, which is considered hardscape)?
Define your project’s LEED boundary, and ensure that it is consistent across all credits pursued by your project. The LEED boundary defines the scope of work, and must include any land that will be disturbed and or used by your project.
You won’t find it in the credit requirements, but the best strategy here is to limit the amount of hardscape and number of parking spaces provided in the first place. This not only reduces the hardscape square footage you must treat with light-colored paving, shading, open-grid paving, or covering, it can also help you earn:
Explore ways to share parking with adjacent sites, and encourage carpooling and other strategies to reduce the amount of parking area needed.
Some strategies for limiting the amount of hardscape include:
After you have reduced your parking hardscape as much as possible through reduced parking spaces, stacked parking, minimizing sidewalks, and other strategies, try the following steps to reduce heat island effect even further.
Determine the square footage of all non-roof hardscape on your site. You'll need to integrate the strategies below for 50% or more of this area.
Although an area of hardscape may meet two different requirements, the area can only be counted once. For example, pavement that is both light-colored and shaded may not be counted twice in credit calculations.
Explore integrating hardscape shading by trees.
Consult with a landscape architect to specify native and adapted tree species with large canopies. This strategy can reduce the number of trees that need to be planted, watered, and maintained—while providing the maximum shading potential.
It is helpful to plant trees in vegetated strips within hardscape areas to maximize the shading potential. Strips can be placed between parking rows, or as a vegetated buffer between surface parking and walkways.
Trees may be able to provide not only shade for hardscapes but also shade and wind protection for the building—potentially reducing cooling as well as heating loads in the building, and saving operational costs.
When calculating the shading area of trees, you may need to use modeling software. Google Sketchup is a free, easy-to-use application that can help you determine shading area. (See Resources.)
To determine the shadow cast by a tree, average the shadow area cast by the three time of day shown in the diagram.Shading is calculated on the summer solstice (June 21). Take the average of the shaded areas measured at 10:00 a.m., 12:00 p.m., and 3:00 p.m.
Consider shading parking with solar PV panels or architectural structures with SRI values of 29 or greater. This is a new path in LEED-NC v2009 path that can likely be allowed for NC v2.2 projects as well (see LEEDuser’s NC v2009 page on SSc7.1 for more detail). Consider writing a CIR to verify this compliance path. .
Explore integrating architectural canopies with an SRI equal to or greater than 29, or photovoltaic (PV) canopies.
You cannot count shading cast from the building itself, as your project building does not cover non-building hardscape area from an aerial view.
Canopies, terraces, balconies, and other architectural devices are covered by the calculations for this credit if they do not have conditioned space below them. Coverings that have conditioned space below are considered roofs and are covered under SSc7.2: Heat Island Effect—Roof.
Explore integrating the use of light-colored hardscape material with an SRI value of at least 29.
SRI is the measure of a material’s ability to reject solar heat and is determined by a material’s light reflectance and heat admittance. For example, dark colors have values close to 0 SRI absorb most of heat they receive, while lighter colors have higher values and tend to reflect heat.
Obtain the SRI value of materials you are considering from the manufacturer.
Power-washing old concrete can help restore it to near-new SRI values. For the purposes of documenting the credit, it is assumed that the material has the new value, unless existing hardscape is being used. For existing hardscape, you must either use the weathered value, or document that surfaces have been cleaned and lightened enough to be equivalent to the default SRI values.
Concrete has higher SRI values than asphalt and so is preferable for this credit. However, it is also generally more expensive than asphalt, but it is more durable and often has a lower life-cycle cost, as it must be replaced less often. This is especially true in high-traffic areas, turnarounds, and areas of heavy-duty vehicle use. If concrete can’t be used everywhere due to the price, use it selectively in high wear-and-tear areas.
Explore using 50% pervious, open-grid paving.
Using open-grid paving allows water to infiltrate the ground, which could also help your project team achieve the stormwater management credits SSc6.1 and SSc6.2.
Open-grid paving is different from porous paving—Open grid paving is laid out in a pattern that exposes areas of the ground allowing vegetation to grow in the open cells. Porous paving is continuous paving that allows water to penetrate it minimizing runoff. Porous paving alone without an open grid will not help you earn the credit, as you need the vegetation and its associated evapotranspiration help mitigate the heat island effect. Porous paving can qualify as a light colored material, however, if it has an SRI of 29 or higher.
The open-grid paving itself should be at least 50% pervious and contribute to 50% of your project's hardscape areas.
Open-grid paving can be just as durable as other types of paving, but it may require additional maintenance to ensure that open cells do not become clogged.
Open grid paving is the most beneficial when it is applied on top of permeable soil that promotes infiltration. Soils with high clay content, or land with shallow bedrock may prevent water infiltration thus making open grid paving less functional.
Determine the number of parking spaces needed for your project. Fifty percent or more of those need to be under cover—underground, under deck, under roof, or under the building. Parking roofs must have an SRI value of at least 29.
Consider locating parking underground, freeing up more site area for other uses, such as larger building footprints, open space, and landscaping.
If 50% of your project’s parking is underground or under the building, there is no parking roof requiring any SRI value. The building roof would be calculated according to SSc7.2 requirements even though the building covers parking spaces.
Parking spots apply to all parking areas within the LEED boundary. Off-site parking outside the LEED boundary is not included in this credit.
Revisit your site hardscape area calculations to ensure that you are still meeting the requirement that 50% of the site hardscape is shaded, open-grid paved, or light-colored—or that 50% of the parking is under cover.
Be sure to collect the SRI values for all hardscape materials you are planning to use toward this credit.
Create a site plan for the LEED submittal that clearly indicates the following:
Include any specific material properties and SRI criteria in the construction and landscaping specifications.
Ensure that the materials and landscaping are used according to your specifications for credit compliance.
Include regular cleaning practices for hardscapes and coverings, especially for light-colored surfaces, as their SRI value will tend to drop, making them less reflective, as they get darker and dirtier. Committing to this is not required to earn the credit, but helps realize the benefit of it.
Include regular weeding practices for any open-grid paving, to keep the material durable and ensure that the spaces do not become clogged.
Excerpted from LEED for New Construction and Major Renovations Version 2.2
Reduce heat islands (thermal gradient differences between developed and undeveloped areas) to minimize impact on microclimate and human and wildlife habitat.
Provide any combination of the following strategies for 50% of the site 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 roads, sidewalks, courtyards and parking lots):
Place a minimum of 50% of parking spaces under cover (defined as under ground, under deck, under roof, or under a building). Any roof used to shade or cover parking must have an SRI of at least 29.
Shade constructed surfaces on the site with landscape features and utilize high-reflectance materials for 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.. Consider replacing constructed surfaces (i.e. roof, roads, sidewalks, etc.) with vegetated surfaces such as vegetated roofs and open grid paving or specify high-albedoAlbedo is synonymous with solar reflectance. materials to reduce the heat absorption.
This is the organization that sets the testing standards for material heat emissivityEmissivity is the ratio of the radiation emitted by a surface to the radiation emitted by a black body at the same temperature. and reflectance that help determine a material’s SRI.
This national association represents concrete pavement contractors, cement companies, equipment and material manufacturers, and suppliers. See Albedo: A Measure of Pavement Surface Reflectance, R&T Update (3.05) (June 2002).
Lawrence Berkeley National Laboratory conducts heat island research to find, analyze, and implement solutions to minimize 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.. Current research efforts focus on the study and development of more reflective surfaces for roadways and buildings.
Use this software to model shaded areas from trees.
This site offers basic information about 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., its social and environmental costs, and strategies to minimize its prevalence.
This site plan from a LEED project shows SSc7.1 compliance, with 50% of parking spaces located under cover.
Check the SRI index of products specified to earn this credit. The pavers in these examples have varying SRI values, some of which would contribute to the credit, and some of which would not.
This calculator produced by Lawrence Berkeley National Labs (LBNL) allows you to compute 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) and roof surface temperature based on solar reflectance and thermal emittance based on ASTMVoluntary standards development organization which creates source technical standards for materials, products, systems, and services standard E 1980.
This template is the flattened, public version of the dynamic template for this credit that is used within LEED-Online v2 by registered project teams. This and other public versions of LEED credit templates come from the USGBC website, and are posted on LEEDuser with USGBC's permission. You'll need to fill out the live version of this template on LEED Online to document this credit.
Documentation for this credit is part of the Construction Phase submittal.
I've got a site plan, and measurements of how big the trees are upon planting. We'll be using Option 1 shading by trees. Anyone know how to calculate how big they will be in 5 years? Maybe a landscaping reference of some kind or a chart?
This is in the Midwest in a wet climate, 32" annual rainfall, and they are deciduous trees, Oaks I believe. Oughtta grow like weeds, no?
Lawrence—I don't know of a reference for this. Let us know if you found something!
Hi! We are using on-site cast grey light concrete and grey concrete stones. The producers have great difficulty to provide the documentation for a certain SRI value, this kind of measurement is not done in Denmark.
LEED provides a typical SRI values, f.ex. for gray concrete 35.
Is it enough to show compliance with this credit by proving that new grey concrete is used?
Yes, we have successfully submitted it that way.
The project I am working on has equipment pads for a generator and cisterns on the site. Additionally there is a concrete pad for a dumpster. Do you think I should count them as part of the paving? They are concrete, so they will comply, but they are essentially covered all of the time.
I would just exclude the areas from the paving because equipment is on top of it. For SSc7.2 you can exclude all skylights and roof top equipment sqft from 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.. It would be logical that the same concept can be allowed for 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..
Is whitish gray pea gravel considered open grid pavement in that it is permeable and reflects more light back than black top would. In other words is pea gravel parking lot not considered a hard scape? thank you!
Hi, if a harscape surface is shaded by trees outside the leed boundary, (but inside the campus where is located the project)., does this area contributes toward this credit?
2. How do you measure the 50% of parking under cover for option 2, only the car space or including the street or space between car park?
1. Unfortunately, I don't think you can count area that is shaded by trees outside the LEED project boundry unless you are attempting a mastersite credit.
2. Typically, you measure the car space area only and not the street and space between the car park. When you fill out the template it asks for the number of car spaces that comply and not the square footage.
Is there a general SRI value for the Open grid system?
I am not aware of an SRI value that applies generally to open-grid pavers. I think it varies. However, I'm wondering why you ask, because for this credit you don't need that information—being open-grid is enough to comply.
There's been a lot of discussion about open parking garages and Option 2.
If I'm attempting to achieve Option 1 and I have parking on the top level of an open parking garage can I count that parking deck towards my non-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.. Since it's not a roof under 7.2 and it's not part of the definition of a footprint it seems reasonable that it be counted as a "parking lot" however "parking lot" seems to imply on-grade.
The parking deck is new gray concrete, SRI of about 35
Tom, what's the SRI of this parking area going to be? Less than or greater than 29?
Okay, I was wondering if you had a low-SRI situation you were trying to find a way out of. Since your SRI is over 29 for the parking area I think you don't have a lot to worry about since however you document the credit, compliance with the intent shouldn't be an issue. Seems to me that calling the top deck the roof of the parking garage and sticking with Option 2 is more straightforward, but that's just my take.
We have a project which is already near substantial completion but the contractor forgot the E-Krete Overlay coating over asphalt paving which gives an SRI of 38. The area that needs to be coated is just 200 sq.m. (2,152.82 sq.ft.), so they suggested to have white paint coating instead of this polymer composite overlay (E-Krete). Is white paint coating accepted for SSc7.1 credit? Please advise.
Tysa, the white paint could be acceptable, but you would need SRI data for it. Also, while LEED would not strictly require this, I would think you would want to make sure that a durable coating is used so that the benefit is retained for the life of the project, or as long as possible.
The majority of the 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. on this project is uncolored concrete, which the manufacturer has provided a chart indicating the SRI of each color. Is this documentation sufficient or will testing be required?
Mahmoud, if the manufacturer can provide data on the SRI of the 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., you don't need to complete independent testing.
Has anyone used shade calculations from the building and other infrastructure, such as an elevated rail line, to demonstrate compliance. This would be in addition to trees.
The credit language is pretty specific about what counts towards shading, and elevated rail isn't included. If it meets the SRI requirement it may be worth trying, no guarantees though.
If the top level of an existing parking deck is used for parking and there are no shading devices of any sort, this would still qualify for Option 2 credit? This is how I read the RG and the conversations on this page. But when I'm trying to document the credit in LO, it will not display as complete until I check the SRI box on the form. Since my parking is all existing and there is zero chance of altering them, I'm stuck with the old concrete at an SRI of 19 per the RG. Any suggestions? I can always go the document and call the problem out to the reviewer route.
the parking garage has parking on the roof as well. does this quality for the non-roof credit?
Gianni, yes, this applies under Option 2 of this credit (non-roof).
I still have queation of the top parking has no shading. is it aplies to Opction2?
Yes. See the Bird's Eye View above where there is an explaination of Option 2.
we have an industrial project in Veracruz Mexico.
All the parking lot is covered and the company is providing a bus service for the employees.
My question is, if the bus drop off zone, or spaces also have to be covered?
The bus just remain in site from 15 to 20 minutes.
Rosamaria, there is no requirement in LEED for parking or a drop-off zone to be covered, so I would say no.
The option under SSc7.1 is for 50% of spaces to be covered, so I would say you're fine either way.
Is your question coming because you are aiming for 100%? What spaces are you referring to in your question?
That's right Tristan! we are aiming for 100% covered spaces.
So far we have all employees, staff, visitor parking spaces covered. But we are wondering if the bus drop off zone will affect pursuing 100% covered spaces. There are like 10 spaces for buses.
Can I come work for you Rosamaria?! My car gets so hot out in the open during the summer!
I'm researching some property that I would like to adhere to as many LEED guidelines as possible. The cost analysis is a bear, but I guess that comes with the territory when combining environmental design and choosing the right property for sale. Is there any advantage to increase from 50% to say 75% or 100%?
In gaining a better grasp on LEED guidelines, there is a delicate balance between budget and adhering to guidelines. Can it be done? Of course, but to do so optimally takes a lot of work. I'm grateful for these forums, since they help to find that point. If I ever find a property for sale that I would like to buy, I'm confident that I can make eco-friendly renovations and stick to a budget. Thanks for the great info!
We are building a clinical expansion to an existing hospital campus. The parking that will be used for this new building will be an already existing parking garage adjacent to the new structure that we will not be affecting during the construction process. Are we allowed to include this garage in the LEED boundary in order to receive credit for parking spaces being under cover? If we do, will the garage also have to be included in the energy model for EAc1? Will it have to be included in SSc8?
Thank you very much for your assistance.
Pablo, for a better understanding of this issue, please review the LEED Minimum Program Requirements supplemental guidance document. There is discussion there of setting the LEED boundary with respect to site features, and how to count them for selected credits. Please post back here with follow-up questions.
Does anyone have an easy way to calculate the area shaded by trees for this credit? I have the anticipated height and canopy diameter of the trees at 5-years. Thanks!
Kristine, I am looking for "when" this calculation should be preformed. I know that I have read the answer somewhere, I just can't remember where. When I was searching different phrases in LEEDuser I found your comment. Are you really working in version 2.2? You may have better luck in version 2009. sara
Kristine and Sara - the credit calculations in the NC version 2.2 Reference Guide state that shade coverage "shall be calculated at 10am, noon, and 3 pm. The arithmetic mean of these three values will be used as the effective shaded area." The v2.2 credit doesn't specify the date for which to calculate these areas, but my understanding is to use the summer solstice, June 21st. (That's made clear in the v2009 credit language.)
As for a method to calculate the area, some projects have used site photos taken on June 21st, but in your case it may be easiest to create a simple SketchUp model with a tree or solid circle sized to represent the tree canopy. Then use the Shading view and set the date and times in the shade options palette and draw a polygon on the ground as an area take-off of the shaded area. Hope that helps.
FYI: The third version of the LEED-NC v2.2. Reference Guide states on page 92: “Shade coverage shall be calculated at 10 a.m., 12 noon, and 3 p.m. on the summer solstice.” Addition of the date was an errata item for page 90 of the First Edition of the Reference Guide. It was codified into the second and third editions.
Sketchup is a good program to use for calculations, or if you've got a lighting designer on your team, they no doubt have access to software like AGI-32, which is what we are using.
Does LEED require a minimum amount of parking spaces to be undercover to achieve this credit. The project has no current parking, and after the renovation and addition, there will be a one-car garage. If I am reading it correctly, according to LEED we would qualify for 7.1 Option 2 with 50% of spaces under cover and obtain an 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. by having 100% of spaces under cover. Is that correct?
I would agree with your assessment. Keep in mind that any roof used to shade or cover parking must have an SRI of at least 29.
We combined parking garage and planted trees to provide shady parking spaces - as well as removed 25% of the old concrete parking lot- dramatically reducing 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. for my project. We were denied this credit. Here is what they said:
A narrative response has been provided to appeal the preliminary ruling which denied the achievement of this credit. However, without prior approval to combine strategies from both options of this credit (by means of 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 Ruling or otherwise), the approach to earning this credit by fulfilling the requirements for one or the other option is the only means to earn this credit.
During the writing of this credit there was no mention of an either/or and during Faculty Training we agreed that we could combing trees and cover...ergh.
Sue, I'm wondering how you proposed to combine Options 1 and 2? They seem to me like apples and oranges—no totally clear way to combine them, which is probably why GBCI didn't allow it. Also, credits where "or" is allowed typically state this.
I do sympthaize since the project seemed to do the right thing.
I don't think the reviewer should be suggesting or requring you to use the 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 process in a review comment.
We have a hotel project which has designated parking on the fourth level of a shared parking garage. These spaces were built prior to the hotel for the hotel’s use, so we would like to take credit for them under SS Credit 7.1, but how can we include them in the LEED site boundary?
You can't include just that floor of parking unless you include the whole building and all that it implies in your LEED boundary. As much as it would be nice to take credit for this, LEED doesn't allow "gerrymandering" of this sort. Other buildings that use the same parking could also take credit for it if that were the case, and that would not make so much sense. (Although I have to admit it's also not totally crazy in this case.)
We have a fire station project in which the city is requiring us to repave a portion of the public streets surrounding the property. Are we required to include this area in our project boundary, and the total overall hard scape area?
My understanding is that because the public streets surrounding the property are outside the property line of the project building, the project site boundary will not have to include these streets and thus they will not have to be included in this credit.
Reducing hardscape can help earn SSc5.2 while making it easier to earn SSc7.1, by reducing the amount of hardscape that needs meet the LEED requirements.
Maximizing vegetated areas and areas paved with open-grid pavers can help reduce stormwater runoff quantity while reducing hardscape that contributes to the heat-island effect.
Vegeated areas and open-grid paving helps stormwater infiltrate into the ground. Promoting infiltration can help filter out polluting particulates, improving stormwater quality.
If shading hardscapes with vegetation, consider using native or adapted vegetation, which will require less irrigation. Open-grid paving can also be placed over rainwater cisterns that can reduce the use of potable water in landscaping.
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