There are eight Resource Categories; each category is broken down into sections, and each section earns points based on importance. Adjustments are made to certification threshold levels to credit smaller house sizes. (Our house required 89 points for Platinum Certification.)Not built on prime farmland as defined by the USDA: Located at the end of an existing field, on a large site planned for conservation.
LL 3.1 Preferred Locations:, Select Edge Development Site: 1 point
Select an edge development site where at least 25% of the perimeter of the development site borders existing development. There are developed lots on two sides of the parcel.
LL 6 Access to Open Space: 1 Point
Within 1/2 mile of publicly accessible green spaces at least 3/4 acres in size:
The site is contiguous with protected woodland extending into a Town of New Milford preserve and Weantinog Heritage land trust preserves totaling hundreds of acres. Walking trail into the preserve starts about 1000 feet east along Cherniske Road.
SS 1.2: Minimize Disturbed area of the site: 1 Point
A landscape plan was developed which included maintenance and enhancement of forest edges adjacent to the building site, to maximize plant preservation and ensure that at least 40% of the lot will be left undisturbed. Building envelope is 2 acres on the 13 acre lot. Excavated and regarded area is about 0.6 acres. Construction access after initial regrading and concrete access is about 0.3 acres. See Site planning and maintenance section and landscape plan in Owners Literature.
SS 2.2; Basic Landscape Design, 2 Points
Drought tolerant turf: The site was seeded with mixtures which included drought tolerant grass species and white clover, which is drought tolerant by virtue of its deeper roots. The variety of grass and meadow species produces a cover which is more resilient to varying moisture and nutrient conditions than the traditional monoculture lawn. The shaded edges of the woodland are left to regrow with woodland vegetation . Careful grading around the house and the use of retaining walls for grade transitions kept slopes of 25% and over to a minimum, to minimize erosion and maximize infiltration. The remaining steeper slopes were marked off and overseeded with wildflower mixtures and mulched, so that mowing will not be needed on the steeper yard areas.
SS 2.3: Limit Turf, 3 Points
None of the landscaped area is conventional turf. Meadow areas and areas left for woodland transition are not included in the calculation of turf area. Areas regularly mowed around the house are a diverse mix of cover species more similar to a meadow community than turf, adapted to both low or no fertilizer and periods of drought. Conventional turf must be limited to less than 20% of the landscaped area to earn this credit.
SS 2.4 Drought Tolerant Plants: 2 points
98 % of the landscape plants (grass, sedges, clover, other meadow species )are considered drought tolerant. Grass species which are more drought tolerant will prevail over the less tolerant in a diverse, low maintenance lawn.
Surface Water Management
SS 4.1: Design Permeable Sites, 4 points
Of the 13 acre site, 99% is vegetated. 1% is gravel driveway.
SS 4.2: Design and Install Permanent Erosion Controls, 2 points
Permanent stormwater controls to manage runoff from the house include setting the elevations of driveway, parking, and house so that runoff will follow broad pathways over gradual grades, with intervening areas of almost no grade, for water to spread and infiltrate and sediment and contaminants to settle out. This is made possible in part by the use of retaining walls against the house for grade transitions instead of steeper earth grades.
SS 5: Non toxic pest control: 2 points
Tight envelope: All cracks and entry points sealed with caulk or other means. Rigid foam foundation insulation is protected with stucco surface. Wood to concrete contact avoided by the use of metal or plastic connectors. Wood is kept well separated from earth and plant material. A margin of crushed stone around the foundation will reduce the plant growth and surface moisture which favors insects. Wood sills on concrete are pressure treated. Aluminum insect barrier installed between foundation and wood sill.
Note re: Rainwater Harvesting System, 1.1: 3 points under this credit might have been achieved using 350 gallons of rainwater storage from roof runoff, for irrigation during the growing season, but it is more challenging to put it to use during the rest of the year. The storage vessel would need to be drained or freeze protected.
No irrigation system designed, as this is usually avoidable with good landscape planning.
Indoor Water Use:
WE 3.1: High Efficiency Fixtures, 2 Points
All lavatory faucet flow rates are less than 2.0 gpm.
Toilet flow rates are less than 1.3 gpf.
WE 3.2: Very High Efficiency Fixtures, 2 Points
Shower head flow rates are less than 1.5 gpm.
ENERGY AND ATMOSPHERE
Energy Star Home Rating of 5+ Stars, HERS index of 30
EA 1.2 Exceeds Energy Star for Homes 28.5 Points earned of a total possible 34.
When the Energy Star Rating System is used, it takes the place of LEED credits EA 2 through EA 10, except that credits remain available for Domestic Hot Water conservation measures in EA 7.1 and 7.2.
This home, in climate zone of 5, achieved an Energy Star HERS index of 30, and an Energy Star rating of 5 + Stars. The energy star rating certificate and Energy Analysis Report are included in the homeowner literature.
LEED Credits for features of this house which are incorporated in the Energy Star rating system are described below:
EA 2: Insulation: (part of Energy Star Credits)
Walls are designed to R40, compared to building code minimum of R19. Loose cellulose, made from recycled paper and a boron based fire and insect retardant, is blown into the cavities in 2x4 stud framing. This method completely fills all voids such as behind electrical boxes with insulation which is much less susceptible to air transmission than fiberglass. Outside the plywood sheathing, 2 layers of foil faced 2" high-R closed cell foam insulation are installed from foundation to roof, eliminating the thermal bridging which occurs when dense framing elements conduct heat through the insulated envelope. The layers of foam have staggered, taped joints, eliminating voids for air transmission. This system provides the air and vapor barrier, effectively at the inside surface of the foam insulation.
The roof is designed to R60, compared to building code minimum of R30. Cellulose is blown into the 2x8 rafter spaces, and 5 inches of hi-R foil faced foam board is installed over the roof sheathing, with joints staggered and taped. This roof layer is continuous with the wall foam layers to minimize air leakage in the entire envelope. With moisture laden air not travelling through the insulated wall and roof space, there is no opportunity for moisture to be conveyed into the structure, and no cold surface within structural elements where moisture can condense and cause problems.
The foundation has 2 inches of rigid foam insulation outside and 3 1/2 inches of cellulose in the 2x4 stud wall inside, for a total of R23. The basement slab has 2 inches of rigid foam underneath for an R value of 10.
See Energy Star Thermal Bypass Inspection Checklist, in Energy Star section of homeowners literature.
EA 3: Air Infiltration(part of Energy Star Credits)
Measures to prevent air infiltration described above. Additionally, window flanges are caulked in place; aluminum insect barrier is sealed to the foundation with non-hardening caulk, and foam sill seal is installed between aluminum insect barrier and wood sill; space between windows and doors and framing filled with expanding foam, and many other measures. A tight envelope contributed significantly to the low HERS rating. The standard for the highest level of LEED credit is based on a blower door pressure test resulting in less than 2.0 Air Changes per Hour at 50 Pascals of pressure (ACH 50). Small houses have a greater exterior surface area than large houses per unit of volume, yet this house tested at ACH 50 of 1.46 ; 25% better than the highest LEED category. All HVAC ducts are inside the envelope insulation, resulting in no loss of energy from ductwork.
EA 4: Windows(part of Energy Star Credits)
Windows are double glazed, argon filled, with Low E glass, to lower heat transmission. Their U value is .33. Energy Star requires a U value of less than or equal to .35. Window area on the north and west is kept to a minimum. West windows typically contribute to overheating, but this house is shaded by the nearby forest in the late afternoon.
EA 5: Heating and Cooling Distribution System(part of Energy Star Credits)
Heating and cooling losses from the ducted distribution system are negligible, as all ductwork is inside conditioned space. Ductwork is sealed for efficiency. Minimal air leakage meets the qualifications for the highest LEED credit in this category.
EA 6: Space heating and cooling equipment: (part of Energy Star Credits)
HVAC design conforms to ACCA Manual J calculation standards as required. A programmable thermostat is installed.
HVAC equipment meets the standards for EA 6.3, the highest level of LEED credit in this category. The boiler is rated by the DOE at 93 AFUE. Weil McLain rates its cold weather efficiency at 98 AFUE. The level required for the highest LEED credit is 90 AFUE. The Hi-Velocity air distribution system is set up for air conditioning equipment with a SEER rating of 15.85 to be installed if needed, which exceeds the minimum rating of 15 for the highest level of LEED credit in this category.
EA 7: Water Heating (part of Energy Star credits)
Our Propane fired combination space and backup water heater exceeds the highest efficiency standard set for LEED credits in this category with an Energy Factor of .88 according to the Energy Star report. The highest LEED standard is an Energy Factor or Combined Annual Efficiency of at least 0.8. The solar water heater is expected to supply at least 60% of the Annual DHW load of the house, the highest LEED standard in this category.
Note: The Energy Factor (EF) for water heating takes into account energy loss from hot water storage in addition to the efficiency of converting fuel to heat, which is the measure provided for space heating appliances by the AFUE.
EA 7.1: Efficient Distribution System: Compact Design of Conventional System: 2 points
Water heater is centrally located to points of use so that the longest pipe run to fixtures is less than 30 feet, with branch lines to each fixture being 1/2 inch diameter. Hot water will be delivered quickly, with a minimum of unused hot water left to cool off in plumbing lines.
EA 7.2: Pipe Insulation: 1 point
Domestic hot water piping has R4 insulation.
EA 8: Lighting: (part of Energy Star credits)
Roughly 25% of the house is using pin based fluorescent, 75% screw base. (Several incandescent bulbs are currently installed for comparison purposes). Energy Star credits a home's energy efficiency for using screw in fluorescent bulbs or for its Advanced Lighting Package using dedicated pin based fluorescent fixtures. There appear to be more options currently in the market for screw base fluorescents and it is likely that advances will occur in this type of bulb at least as rapidly as for pin based bulbs.
EA 9: Appliances: (part of Energy Star credits)
The refrigerator, dishwasher, clothes washer, and ceiling fan are specified as Energy Star efficient. A "Very Efficient" clothes washer will conserve water as well as electricity.
EA 10: Renewable Energy: (part of Energy Star credits)
The 2kw Photovoltaic system installed is estimated to produce between 30 and 50% of the energy efficient home's annual electric needs. There is room on the roof to expand to a 3 kw systems, and the power inverter in the basement is sized for this expansion capability. This may be the equivalent of about 3 or 4 LEED points of a total of 10 available in this category.
EA 11: Residential RefrigerantManagement: No refrigerants used: 1 point
Air conditioning equipment not installed; not needed.
MATERIALS AND RESOURCES
Environmentally Preferred Products:
MR 1: Material Efficient Framing
Various measures are suggested in the LEED manual to reduce the volume of framing material used in construction. Our choice to use 2x4 studs and 2x8 rafters with a custom designed envelope using both rigid foam and cellulose meant that framing material did not need to be oversized beyond structural requirements just to provide thickness for insulation. 2 x 4 studs are each, and presumably in the aggregate, about 64 % of the wood volume of a 2x6 stud. 2 x 8 rafters are 80% of the wood volume of 2x10 rafters, which are usually used to accommodate R30 fiberglass insulation. The 2x4 wall takes up 64 % of the footprint of a 2x6 wall, allowing us to use resource- intensive built area as living space instead of wall thickness.
Spacing at 24" o.c. instead of the 16" spacing we used would reduce the number of framing pieces in a standard run by 33% and earn 1/2 LEED point. But the necessarily increased rafter depth and probably stud depth, and the reduced frequency of attachment for finished surfaces would have been offsetting disadvantages. The LEED manual did not offer points for our system, but the thinking involved is worth noting.
MR 2.2: Select Environmentally Preferred Products from List: 10 Points
(The maximum of 8 points allowed for this category are credited here, with the two points achieved beyond the 8 maximum used as an ID 3.1credit.)
Floor/Flooring: 1 point:
45% of floor area is either reclaimed tile or sealed concrete finish floor. These and the Vermont ash finish floor, milled in Woodbury, CT, are counted as locally sourced (extracted, processed, and manufactured within 500 miles of the home)
Floor/Carpet: 1/2 point for no carpet in house.
Foundation aggregate and cement: Total 1 point for local source.
Interior wall and ceilings; gypsum board: 1 point for recycled content and local source.
Interior walls, ceilings, and millwork; paint: 1/2 point for Low VOC EcoSpec and natural oil finishes.
Landscape/ Decking or Patio: 1 point for locally reclaimed material.
Other/Cabinets: 1 1/2 Points for material milled from reclaimed city logs, sheet wood products with no added VOC's, and locally sourced from Citilog in Pennsylvania.
Other/counters: 1/2 point for reclaimed Fireslate counters in kitchen and baths. (No credit available here for locally reclaimed)
Other/ Trim: 1 1/2 points for trim reclaimed from recovered city logs, solid wood with no VOC's, and locally sourced.
Roof/Roofing: 1/2 point for recycled content in steel roofing. Steel is also eminently reusable and recyclable.
Roof, Floor, Wall Insulation: 1 point for recycled, locally sourced cellulose framing infill insulation.
Investigated and documented local options for diversion of construction waste
MR 3.2: Waste Reduction: 2 Points;
generated 7.98 cubic yards of construction waste per 1000 s.f. of floor area, for a reduction of 69% below the standard waste volume for ordinary construction sites. Material was ordered and used carefully. Potentially useful scrap was piled accessibly and much of it used up during the job. Recyclable cardboard, steel, and cans and bottles were stored and taken to the local recycling center. Remaining clean burnable solid wood scrap was burned in a woodstove in the basement to heat the house during construction, reducing the need for fossil fuel burning heaters.
INDOOR ENVIRONMENTAL QUALITY
Prerequisites include all combustion equipment with closed combustion, dedicated air supply, carbon monoxide moniter installed on each floor, and airtight woodstove.
IEQ 2.2: Install High Performance Fireplace: 1 point
The Vermont Castings Encore non catalytic stove has the lowest emissions at 0.7 g./hour among EPA rated non catalytic wood stoves, comparable to the lowest emission catalytic stoves. A direct air supply is attached to the stove to provide combustion air and draft in a tight house to avoid sending conditioned air up the chimney, and to avoid smoke backdrafts when exhaust fans are operated in the house.
Outdoor Air Ventilation:
IEQ 4.2 Enhanced Outdoor Air Ventilation with Heat Recovery: 2 points.
Fully ducted Heat Recovery Ventilator with a capacity of 200 CFM draws exhaust air from bathroom locations on three levels (rough plumbing provided for bathroom in basement level) as needed and according to a schedule programmed at a central control in the main hallway. Fresh air conditioned with heat recovered from outgoing air is delivered to living spaces on all three levels.
IEQ 4.3 Third Party Testing of outdoor air flow rate into home: 1 point.
Tested rate of outdoor air flow into home with HRV ventilator at high speed is 154 CFM.
Installed in bathrooms and kitchen, using Energy Star or central exhaust fan (HRV)
IEQ 5.2: Timer/Automatic Controls for Bathroom Exhaust Fans: 1 point
Each bathroom location has a timed exhaust fan control. The central hallway controller has an automatic humidistat which turns the air exchange fan on high when house humidity exceeds the set point.
IEQ 5.3: Third party testing of exhaust air flow rate out of home: 1 point
The kitchen hood exhaust fan tested at 227 cfm. The two bathrooms tested at 62 and 50 cfm.
Supply Air Filtering
IEQ 7.2: Install Filters of MERV 10 or better, with adequate system air flow: 1 point
Installed MERV 11 filter. This should be checked or changed every three months or so during operating seasons to maintain air flow and filter effectiveness.
IEQ 8.1: Seal off ducts during construction: 1 point
Ducts sealed with tape during construction to prevent dust from entering the air distribution system.
IEQ 8.2: Indoor Contaminant Control: 2 points
We installed permanent walkoff mats at each (2) main entry. These are recycled plastic grates installed flush with the front porch floor and in a frame set at grade outside the west entry. Each have space under the grate for material to accumulate for periodic removal. We built a seat and shelves next to the main entry for removing and storing shoes, to reduce the introduction of particulates to the indoors.
IEQ 8.3: Flush Home Continuously for 1 week with the windows open: 1 point
HVAC system fan running continuously during flush-out.
IEQ 9.2: Install Radon Resistant Construction if home is not in EPA zone 1: 1 point
The house has a radon ventilation system consisting of 4" perforated pipe in the crushed stone under the basement slab around the perimeter of the basement, connected to a 4" solid pipe flue opening through the roof near the ridge. Natural convection would vent radon if it was present. This or a comparable system is a required prerequisite in a zone where the EPA considers radon to be prevalent (Zone 1). It earns a credit when installed in homes in areas such as the local Zone 2 where radon is less prevalent.
Garage Pollutant Protection:
IEQ 10.4: Detached garage or no garage: 3 points
Garages near living spaces may create indoor air quality conditions which need attention. If a garage is planned in the future, consider a detached garage to keep air pollutants away from living space.
AWARENESS AND EDUCATION
Education for Homeowner and/or Tenants
AE 1.2 Enhanced Training: 1 point
In addition to the basic operations manual and training, we will sponsor open houses for realtors and potential home buyers informing participants of the unique features of a LEED home and discussing subjects related to the efficient use of resources and the appropriate use and maintenance of the measures and systems which are incorporated in sustainable home design and construction.
AE 1.3 Public Awareness: 1 point
We have published information about this house and Green Building here on our website, which we will be updating. We have generated news articles (Litchfield County Times and GreenBuildingAdvisor.com) explaining our design program and certification level, and display a LEED for Homes sign indicating our certification level. We will sponsor tours with interested organizations such as the Housatonic Valley Association, the Connecticut Chapter of the U.S. Green Building Council, and the Northwest Conservation District, in addition to realtor and prospective buyer open houses.
TOTAL POINTS for this project: 89.5