- LEED Introduction
- Sustainable site
- Energy & Atmosphere
- Indoor Environment
- Water Efficiency
- Materials and Resources
o (Prerequisite) Framing Order Waste Factor Limit- 1 point
- Unfortunately, the first objective most contractors prioritize does not involve how much was is being sent off to landfills. LEED mandates limiting waste to 10% of the wood material ordered to build your home. This helps limit the waste produced as well as the destruction of old-growth forests.
o Detailed Framing Documents- 1 point
- Knowing precisely what materials are needed is crucial in sustainable building. Also, creating detailed framing plans using optim um value engineering will help reduce the cost of materials, resources, and labor. This will lessen the environmental impact the build has and dramatically reduce building cost as well.
o Detailed Cut List and Lumber Order- 1 point
- The framing plans will then allow for exact cutting measurements which will further reduce waste.
o Framing Efficiencies- 3 points
- Using advanced framing techniques, or optimum value engineering, will allow you to use less wood which in turn will allow for the goal of using more insulation. If the requirements are met in only 50% of the walls, only half the credit will be awarded.
Advanced Framing/ Optimum Value Engineering
Advanced Framing : Video
- 24” On Center Framing
- Normally walls and floors are framed with 2”x4” studs spaced 16” apart. Using 2”x6” studs spaced 2’ apart will allow for more insulation without compensating the wall’s integrity.
- Stack Framing
- Simply aligning the studs in the framing of the wall and the floor will allow for more efficient load transfers. This als o allows for single top plates, as opposed to double, which in turn means a better fastening of the plywood that spans the transition.
- Coordination of Doors & Windows
- P lacing doors and windows alongside the 2’ framing grid helps reduce waste and allows for more insulation.
- Turned-Stud Cornersor “California Corner” Framing
- Rotating a 2”x6” (as shown in the diagram) will allow for more insulation of the space. It also allows for faster framing since there is no need to measure for inside wall placemen
- Ladder Framing
- Small blocks of 2”x4” cut to fit between the 2’ spacing will allow for easy attachment of interior walls to the exterior. Three blocks should be used for an 8’ wall and four for 10’.
- Metal Hangers
- Instead of jack joints, meta joist hangers (I-joist) will provide the support needed while simultaneously allowing for more space for insulation. An I-joist the I-joist is a man made engineered wood product which has incredible strength in relation to its size and weight.
- Omit unnecessary headers
- Non-load barring walls do not require the use of headers over windows and doors. Not having them here will reduce lumber use and still maintain its structural integrity.
- Replacement for Sheathing
- Rigid foam insulation reduces thermal brigding, the transfer of heat or cold through wood framing. An example of this is STYROFOAM™ Brand Residential Sheathing. This is an extruded polystyrene foam board with plastic film facers on both sides to reduce job site damage to the insulation boards. In new construction and residing applications, it provides a level, even surface for the exterior sheathing and for new siding material, plus helps enhance energy efficiency, reduce condensation and create an attractive, long-lasting home exterior (Dow Building Solutions).
- Building a house that is 24,000 sq. ft. will save approximately $1000 and provide for 8% more insulation when using advanced framing techniques. This is beneficial since the r-value, the resistance to heat value, of wood is much less than that of fiberglass batting. All this extra insulation is crucial in keeping heat in as well as keeping it out efficiently.
- Easier to walk between studs with larger tools and nail bags.
- Walking along a 5 ½” wall is much safer than walking along one that is one 3 ½”.
- The weight of the walls is dramatically reduced.
o Off-Site Fabrication- 4 points
- Points are awarded here had the construction of the framing taken place at a separate location, in which case points would not be available elsewhere in this MR subcategory.
Habitat for Humanity and LEED standards
This year will be the 17th Collegiate home built by the ISU/IWU HFH chapters. The standards for this house were less than that of others merely because of its size, but the goal of a platinum rating was still unreachable. The progress thus far has been substantial but could have been more efficient in terms of framing. Though ‘off-site fabrication’ was practiced, the framing plans could have been much more efficient. Here is a check list of inefficiencies that I have taken note on.
- Studs used were 2″x4″ rather than 2″x6″ which restricted the amount of insulation that could have been used.
- Approximately 2624³ in. of ‘extra’ 2″x4″ was used as “cripples for the windows
- Headers on non-load barring walls were used wasting about 2160³in.
- 3072³ in. of extra 2″x4″ was used in order to adjoin exterior walls to interior walls. This framing technique also restricted the use of more insulation and will now provide an escape for heat or an entrance for cold.
LEED for Homes Rating System
Advanced Framing Video
STYROFOAM Brand Resident Sheating