Sustainable Concrete Solutions for LEED for Homes 

 

Sustainable Concrete
Solutions for LEED for Homes 


What is LEED for Homes?

LEED for Homes (LEED-H) was released by the United States Green Building Council in January, 2008. The program is intended to cover single-family houses, production and custom, as well as low-rise multifamily applications of three stories or less. The stated goal of the USGBC is to provide a residential sustainability system that transforms the design of mainstream homes. Designers and homebuilders can differentiate themselves by providing homes that are recognized as high-quality green homes. Homeowners can rely on an easily recognizable “brand” when purchasing a sustainable home. Table 1 shows the various certification levels and the number of points required for a home to meet each level. Table 2 provides a listing of the LEED-H Resource Categories where concrete can contribute to a project’s qualifying for certification.

What about the exterior envelope?
Above-grade concrete wall systems deliver on durability, providing unparalleled disaster and wind resistance.Unlike conventional systems, they're inherently fire and pest resistant, will not promote the growth of mold and mildew, and will not decay. Panelized systems virtually eliminate construction waste. The cement in concrete systems can be supplemented with industrial by-products like fly ash, reducing burdens on landfills.

How about concrete finishes?
Finishes also have a big impact on the long term performance of a home. On the outside, the hardness and durability of exposed concrete, concrete masonry, or applied concrete finish systems like stucco or fiber cement siding and trim, will provide durability to reduce the frequency and cost of maintenance and replacement. Concrete roof tiles adhere more effectively in high winds, stand up to hail and fire, and last far longer than ordinary shingles.

And the indoor environment?
Inside, airtightness is improved because concrete wall systems reduce joints and penetrations. Higher levels of insulation, and the thermal mass of the concrete, make mechanical systems more efficient and more effective in maintaining good indoor air quality, with more constant temperatures and fewer drafts. Concrete floor systems can provide rich, high-quality, water-resistant floor finishes. Concrete roof tiles have been shown to keep attics cooler, further reducing mechanical loads.
 

Bottom Line: By using concrete systems and finishes, homebuilders and designers can more easily achieve LEED-H certification for their homes. Whether through contributions based on the resource categories outlined here, or through accepted submissions for sustainable innovation credits, a concrete home provides the long-term, high-quality residential performance the USGBC is striving to encourage with LEED for Homes.

 

Table 2: LEED for Homes
Potential Contribution to Project Credits - Sustainable Concrete Benefits

Resource Category

Credits

Resource Sub-Category

Concrete Benefit

ID - Innovation and Design Process

Prerequisite

ID 2.1 Durability Planning (Pre-Construction)

Unparalleled disaster and wind resistance, durable long lasting finishes, low maintenance, less frequent replacement, mold and mildew resistance

ID 2.1c Indoor Moisture Control

SS-Sustainable Sites

0.5-1.0

SS 5 Nontoxic Pest Control

Concrete wall, floor and roof systems eliminate invasive, expensive and environmentally hazardous chemical termite treatments needed with wood framing.

WE - Water Efficiency

1.0-5.0

WE 1.1 Rainwater Harvesting System

Capture and control rainwater and graywater with concrete cisterns

 

WE 1.2 Graywater Reuse System

 

EA - Energy and Atmosphere

Prerequisite
2.0-34.0

EA 1.1 ENERGY STAR Performance
EA 1.2 Exceptional Energy Performance

Unparalleled combination of high R-values, very low air infiltration, and thermal mass benefits of exterior walls.

2.0-5.0

EA 2 Insulation
EA 3 Air Infiltration

Inherent continuity of insulation and air barrier in concrete wall systems simplifies on-site detailing and required inspection procedures

MR - Material and Resources

4.0

0.5-3.5

MR 1.5 Off-Site Fabrication

Panelized concrete wall, floor, and roof systems can all be manufactured off-site to reduce waste

Concrete exterior walls and foundations with recycled fly ash or slag, recycled content in fiber cement siding, concrete masonry, concrete patios, countertops, and roof tiles, sealed concrete floors as alternative to high waste volume generated by carpet. All potentially locally derived materials.

MR 2.2 Environmentally Preferable Products

0.5-3.0

MR 3.2 Construction Waste Reduction

Demolished concrete can be crushed and reused as base material or fill

IEQ - Indoor Environmental Quality

13.0

EQ 1 ENERGY STAR with Indoor Air Package

Durable exterior envelope, effective mold and moisture resistance, reduced air infiltration, non-toxic pest control alternative, low-VOC sealed concrete floors

AE-Awareness and Education

Prerequisite

AE 1 Education of the Homeowner

Concrete systems are more durable, long lasting, presenting home owners with a more trouble free low maintenance environment