If an existing building plays a starring role in your project, it’s a good candidate for this credit, which rewards the reuse of buildings and their structural components. In this way you can reduce the energy- and resource-intensive manufacturing of new materials, while prolonging the enjoyment of a building’s character and history. If the existing building plays only a small role, on the other hand, it is less likely to qualify for this credit, although it may contribute to materials reuse credits. If a project includes new construction in addition to building restoration, the project is only eligible for the credit if the floor area of the new construction is no more than two times the floor area of the retained existing structure.
A LEED for New Construction registered project can earn up to two points for reusing 75% (1 point) or 95% (2 points) of an existing building, as well as being eligible for MRc1.3: Building Reuse—Maintain 50% of Interior Non-Structural Elements.
Evaluate credit eligibility and targets using the eligibility and building reuse calculators available in the Documentation Toolkit. The process of documenting this credit by accurately measuring the area of building elements and tabulating them in the Building Reuse calculator can be fairly time-intensive. When measuring, be sure to consistently follow the credit rules and not double-count elements. In addition, a structural survey must generally be performed to confirm the integrity of the structures and identify any load restrictions. Non-structural elements may also require study by a qualified professional.
This 100-year-old building is undergoing exterior and interior renovation for condominiums. The building's structure and shell will be reused. YRG Photo
If considering a site with an existing building, evaluate the drawbacks of renovation and restoration compared with demolition and new construction.
Building reuse maintains cultural and historic heritage in addition to extending the useful life of the building and materials. Tax credits and even grants may be available from local and federal authorities for rehabilitating historic buildings. These incentives usually require the redevelopment to be historically sensitive, and community input may also be required.
Hazardous materials such as asbestos and lead may be present in older buildings. The owner may benefit from conducting a Phase I Environmental Assessment, and if required, a Phase II assessment with a remediation plan to ensure a safe and healthy facility.
Large cost savings for the owner, along with reduced waste and resource use, can be benefits of building reuse. Perform a budget comparison of new construction versus restoration to make an informed decision.
You may find a tradeoff between building reuse and overall environmental performance, specifically in terms of indoor air quality and energy efficiency. Although many older buildings are energy-efficient compared to average new construction, it is typically more difficult to attain the highest levels of building performance due to the constraints of the existing building. Look for areas where this tradeoff may appear, and mitigate them by identifying measures most likely to result in improved performance. For example, an historic building with a load-bearing masonry wall may not be a good candidate for adding wall insulation. Try to improve thermal performance in other areas like roof insulation, reducing infiltration through windows, and using more efficient HVAC systems.
The architect determines project eligibility for the building reuse credit based on pre-design assessment. A project is eligible if it is reusing an existing structure with no addition, or if the total gross square foot of the final project with the new addition would be less than two times the gross floor area of existing floor area. Use the Documentation Toolkit calculator to determine eligibility.
Projects ineligible for the building reuse credit can count the reused building area towards MRc2: Construction Waste Management for recycling or otherwise diverting waste, or MRc3: Materials Reuse for materials that are reused on-site in a different application (such as door used as a countertop).
Incorporate restoration specifications into the construction documents.
List and tabulate in the Building Reuse Calculator all of the exterior and structural elements being reused, restored and renovated in the project.
The Building Reuse calculator (see the Documentation Toolkit) helps in tabulating and obtaining a reuse percentage for credit targets. This data can be transferred to LEED Online after being finalized. Use these guidelines in carrying out the calculations for Building Reuse.
Building elements removed because of hazardous materials do not count against you, because they are excluded from both the tally of existing elements, and from reused elements.
Many older buildings are energy-efficient compared with average new construction, but can be challenging to bring to a level of higher performance. Consult building science experts to avoid moisture and structural problems, and consult with historic preservationists to make sure that any solutions don’t conflict with historic standards, if relevant. For example, in buildings with load-bearing masonry walls, building scientists tend to want to insulate the exterior, while preservationists may object to changing the appearance of the building. Adding equipment like cooling towers may conflict with a building or neighborhood’s historic character.
Work with the restoration contractor on appropriate demolition and restoration activities that support this credit and other resource reuse credits.
To document the credit, develop a floor plan showing the location of existing structural components, floors, roof deck, exterior walls, and internal structural walls, and identify each that are reused. See the Documentation Toolkit for an example floor plan and elevation.
Take photos of exposed cavities to document complicated structural systems and future use in installation of utilities or planning renovations.
Protect existing elements during demolition and construction so that they can be reused. Renovation and restoration may be labor-intensive; make realistic plans in advance.
Before completing LEED documentation, the architect or responsible party revisits the tabulation of existing and reused elements to confirm that the percentage of reused building elements is above the threshold required for LEED.
The architect or responsible party drafts a narrative describing the project’s approach to building reuse, including the selection of preserved elements, and any outstanding project features.
Special finishes and materials may be used during construction to maintain a certain aesthetic or historic integrity. Be sure that operation and maintenance guidelines are developed that account for these factors.
Excerpted from LEED for New Construction and Major Renovations Version 2.2
Extend the life cycle of existing building stock, conserve resources, retain cultural resources, reduce waste and reduce environmental impacts of new buildings as they relate to materials manufacturing and transport.
Maintain at least 75% (based on surface area) of existing building structure (including structural floor and roof decking) and envelope (exterior skin and framing, excluding window assemblies and non-structural roofing mate- rial). Hazardous materials that are remediated as a part of the project scope shall be excluded from the calculation of the percentage maintained. If the project includes an addition to an existing building, this credit is not ap- plicable if the square footage of the addition is more than 2 times the square footage of the existing building.
Maintain an additional 20% (95% total, based on surface area) of existing building structure (including structural floor and roof decking) and envelope (exterior skin and framing, excluding window assemblies and non-struc- tural roofing material). Hazardous materials that are re-mediated as a part of the project scope shall be excluded from the calculation of the percentage maintained. If the project includes an addition to an existing building, this credit is not applicable if the square footage of the addition is more than 2 times the square footage of the existing building.
Consider reuse of existing, previously occupied buildings, including structure, envelope and elements. Remove elements that pose contamination risk to building occupants and upgrade components that would improve energy and water efficiency such as windows, mechanical systems and plumbing fixtures.
Pittsburgh Papers: Best of GreenBuild, November 12-14, Pittsburgh, PA, 74-81. Pulaski, M., Hewitt, C., Horman, M. and Guy, B. 2003.
A fascinating study of how buildings evolve or disintegrate after they're "finished," and how to design for their ongoing evolution. Great photos and anecdotes throughout illustrate Stewart Brand's theories, which are a compelling and easy read. A great book for lovers of old buildings, but also for those building new buildings that they wish to have a long, rich life.
ASTMVoluntary standards development organization which creates source technical standards for materials, products, systems, and services 1527-05 Phase I environmental assessment is a report prepared for the real estate holding that identifies potential or existing environmental contamination liabilities.
ASTMVoluntary standards development organization which creates source technical standards for materials, products, systems, and services 1903-97 Phase II environmental site assessment is an investigation that collects samples of building materials to analyze for quantitative values for various contaminants.
Use these documents to determine eligibility for the project, if including an addition. The new construction must be not more than two times the existing floor area.
The building reuse calculator helps in tabulating and obtaining a reuse percentage for credit targets. You can then transfer this data to LEED Online.
To document this credit you'll need a floor plan and elevation identifyng the structural components that are retained and those that are demolished. It verifies the accuracy of elements included in the building reuse calculations.
Use this calculator to tabulate the reused interior components and assess credit compliance.
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 have a project with a large existing wall. The wall will be covered with thin metal paneling but underneath is the existing structure. Can I count the surface area of this wall toward the credit?
Lauren, to me this sounds like waste reduction but not what this credit is all about. I think we have an FAQ on the v2009 version of this credit that speaks to this point a bit more.
Thanks for your response. The wall itself is an existing wall and so I think should count toward this credit.
Sorry, I was thinking about this in terms of the interior surfaces credit. In terms of plain building reuse, I'd count it.
My project has some above grade attached porches. I have to replace the existing tongue & groove decking but not the framing. How do i calculate the sf of the framing?
I would use the surface area of the deck for this figure.
Thanks for your reply. In regards to the same project, we are demolishing some stairs and re[placing. Do stairs have to be counted/included for Credit MRc 1.1/1.2?
You're still talking exterior? I think all exterior stuff like this is a bit of a gray area. If the stairs were make-or-break, I'd exclude them, but otherwise I'd include the area from plan view just to be conservative.
Our project will contain a 8'x8' walk-in cooler that will be either be connected directly to the building or wil stand alone, a couple of feet away from the building. This equipment falls under Division 11 (Foodservice). Would the walk-in cooler be considered an 'addition' to the building? Thank you
Diane, it sounds like part of the building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint., if it is connected to the building, although I'd be interested in hearing any other interpretations.
If it is separate from the building, then you could consider it an accessory structure, which could have some implications should you choose to use them. See the Minimum Program Requirements supplemental guidance document, and information on accessory buildings in project boundaries.
How do core drills & MEP penetrations through the structure handled in this credit? Should they be subtracted and accounted for in the reused area?
Diane, if I understand your question correctly, you're asking whether part of a wall, for example, that is removed for a MEP penetration, should count as reused area. It seems to me like it should not, because that particular wall area is not reused.
If MEP peenetrations are going to make your break your reuse calcs, you must be on a razor's edge!
I have a major renovation project that has multiple brick clad structural piers (that are to remain). How do I calculate the s.f. of those elements? Or, do they fall under the "columns" and therefore excluded.
Based on your description, it sounds like the piers could fall someplace in between structural columns and interior structural walls. The conservative approach would be to lump the piers in as a structural column. However, if the piers are large, you could make the argument that they are interior structural walls, the call is yours.
We are building an addition that is sandwiched between 2 buildings. The current two building exterior facades will become interior walls when complete. We are not demolising and rebuilding but rather integrating the two existing exterior walls in the new building. Isnt this reuse? We are saving nearly 95% of these two walls and they will account for more than 50% of the new building's 'exterior' structure.
What are you defining as the final "building" for your LEED certification? Is it the addition that's the sandwich filling, or is the whole building/sandwich to be LEED-certified?
The addition is the LEED project and it is only the "sandwich filling". One of the adjacent buildings is already LEED CI Gold. So we are only cutting a few access 'holes' in existing walls and reusing them for the new building.
My interpretation would be that you can't claim materials reuse because the square footage of the "addition" dwarfs the size of any existing building reuse that you could try to claim.
Buildings in this situation often can put the building reuse toward MRc2: Constrution Waste Management, as the reused material is diverted from the landfill, but since those walls are a part of other buildings that are not in danger of getting rid of them, this seems like a stretch.
Does this make sense? Any other angles I'm not seeing?
1. Our project has concrete structural floor slabs, overlaid with a couple inches of topping slab, which does not function as part of the structural floor system. We are generally retaining the topping slab, but in certain areas we need to demolish it -- but leave the structural slab untouched -- for horizontal conduit runs, etc.
Do we need to count the areas of topping slab demolition as 'demolished' floor for the purposes of MRc1.1/1.2? If so, is there any provision for counting those SF as 'partially' demolished, since only 50% of the combined depth of the structural and topping slabs is being demolished?
2. For interior structural walls, the NC 2.2 Reference Guide says to "calculate the surface area ... of both sides of the existing wall element." Under NC 2009, the calculation is of one side (which makes much more sense). Is *both* sides actually correct for NC 2.2?
For question #1, credits MRc1.1 and 1.2 refer to maintaining the existing building structure. Thus, the replacement or repair of portions of the non-structural topping slab shouldn't impact the calculations.
For question #2, that's really an NCv2.2 MRc1.3 question, and from what I can see the calculation method has remained the same in version 2009, though in 2009 it is covered under MRc1.2- check out page 353 in the reference guide for more details.
Short answer- you count both sides of an interior non-structural wall.
Thanks for the confirmation on #1. On #2, the NC2.2 reference guide does indicate to calculate both sides of structural walls (p.244), as well as non-structural. I asked the question because I wanted to make sure that hadn't been changed by some later addendum, etc., since it seems so illogical (i.e. why would you count both surfaces of an interior wall, but only one surface of an exterior wall?). Glad they have changed it in 2009.
Thanks for the clarification. I agree with you, it seems very odd to count both sides of an interior structural wall for the MRc1 calculations. As there are no memos, addendums or CIRs indicating a change/correction, I would assume that v2.2 calculations should include both sides of an internal structural wall, and v2009 includes only one side.
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