Chaleff Residence
GREEN BUILDING is building with environmental impact factored into the process. The designer operates with knowledge of materials processing, the physics of energy fluxes and a sense of the built environment acting as an “armature” for the social environment. All of this is considered in addition to the usual architectural issues. This residence is an example of sustainable building through the workings of its materials. Specific components of the solution are described below:
1. Site selection and site responsive forms.
The lot is a strip between historically farmed land and a secondary road. The older, taller trees are part of a “shelter belt” that modified the effects of winter winds blowing across the road. Since this is not a Village lot, rigid conventional right-angle geometries were deemed inappropriate. Organic forms were sought that could be constructed economically. The retaining walls and the elimination of the straight ridge were attainable without incurring a heavy premium.
2. Principal Structural Elements.
The exterior walls and roofs are constructed of Structural Insulated Panels (SIPS) that are sandwiches of Oriented Strand Board (OSB) with expanded polystyrene form (coffee-cup stuff) cores all glued together without formaldehyde resins. There are no studs or rafters. The panels combine with screwed connections to form assemblies up to three times stiffer than conventional stick constructions. The thermal resistance of the envelope to heat losses by conduction and infiltration is about 3 times greater than conventional stick frame. The OSB is fabricated from “weed” trees or “plantation” trees rather than prime sections of prime trees. The foam may contain a large fraction of “regrind” (post-consumer recycled foam waste). And is fabricated with no ozone-depleting CFC’s or HFC’s.
3. Other Structural Components.
The beams and trusses are fabricated with parallel-strand lumber (PSL) which uses pencil-sized pieces of Douglas Fir. This engineered product is stronger and stiffer than solid-sawn timber and will not crack, warp, split, or shrink. It is manufactured without formaldehyde resins. The floor joists - and the wall studs - are steel and not prime Douglas Fir. The steel is cheaper and will not check, warp or shrink. Most importantly, all drywall is screw-fastened so there are no nail-pops.
4. Heating, Ventilating, and Air-Conditioning System.
The propane-fired boiler has a fuel efficiency rating of over 95%. It is directly vented through the wall and combustion air is drawn into the sealed combustion unit. Even if there is negative pressure in the house, there is never any danger of the products of combustion going into the house. The hot water is used to provide hot air (via a coil at the blower) and through coils, power two hot water tanks (one up and one down). This highly efficient package can be switched if street gas becomes available. Waste hot water has its heat reclaimed with a heat exchanger.
5. Air Circulation.
The hot air is driven under the floor and forms a blanket that flows under the entire floor through to the perimeter registers. Half the heat is delivered convectively from the registers and half radiantly from the floor. The central return is at the highest point of the house collecting the stratified hot air and recycling it down through the floor. As with all hot air systems, all the air goes through one point and may therefore be filtered and humidified or dehumidified as well as heated or cooled.
6. Passive Solar Design.
The south façade is predominantly glass; the north, opaque. This minimizes heat losses to the north and allows the sun to shine in a heat up the floor. The floor mass prevents overheating and continues to release heat to the space through the night.
7. Interior Finishes.
The drywall utilized throughout is finished with latex paint and primer. Most major manufacturers have a line with minimal volatile organic compounds, some very sensitive people may require stricter control of paint finishes and can obtain milk-base paints and stains or finishes manufactured entirely with natural organic materials such as boiled linseed oil, shellac or tung oil. Heavy metals and VOC’s are carefully excluded by some manufacturers. The Masonite doors have a clear lacquer finish.
8. Exterior Finishes.
The roofing is “Ondura” by Ondura Corporation in Fredericksburg, VA/. It is asphalt-impregnated cellulose (with a high recycle content) and sports a lifetime warranty. It costs approximately the same installed as laminated shingle roofing. It may require resurfacing with a latex paint every 10-15 years.
The siding is Hardiplank, a composite material of sawdust and aerated autoclaved concrete. It is fireproof, rot-proof, and termite proof, and comes with a 50-year warranty.
The lot is a strip between historically farmed land and a secondary road. The older, taller trees are part of a “shelter belt” that modified the effects of winter winds blowing across the road. Since this is not a Village lot, rigid conventional right-angle geometries were deemed inappropriate. Organic forms were sought that could be constructed economically. The retaining walls and the elimination of the straight ridge were attainable without incurring a heavy premium.
2. Principal Structural Elements.
The exterior walls and roofs are constructed of Structural Insulated Panels (SIPS) that are sandwiches of Oriented Strand Board (OSB) with expanded polystyrene form (coffee-cup stuff) cores all glued together without formaldehyde resins. There are no studs or rafters. The panels combine with screwed connections to form assemblies up to three times stiffer than conventional stick constructions. The thermal resistance of the envelope to heat losses by conduction and infiltration is about 3 times greater than conventional stick frame. The OSB is fabricated from “weed” trees or “plantation” trees rather than prime sections of prime trees. The foam may contain a large fraction of “regrind” (post-consumer recycled foam waste). And is fabricated with no ozone-depleting CFC’s or HFC’s.
3. Other Structural Components.
The beams and trusses are fabricated with parallel-strand lumber (PSL) which uses pencil-sized pieces of Douglas Fir. This engineered product is stronger and stiffer than solid-sawn timber and will not crack, warp, split, or shrink. It is manufactured without formaldehyde resins. The floor joists - and the wall studs - are steel and not prime Douglas Fir. The steel is cheaper and will not check, warp or shrink. Most importantly, all drywall is screw-fastened so there are no nail-pops.
4. Heating, Ventilating, and Air-Conditioning System.
The propane-fired boiler has a fuel efficiency rating of over 95%. It is directly vented through the wall and combustion air is drawn into the sealed combustion unit. Even if there is negative pressure in the house, there is never any danger of the products of combustion going into the house. The hot water is used to provide hot air (via a coil at the blower) and through coils, power two hot water tanks (one up and one down). This highly efficient package can be switched if street gas becomes available. Waste hot water has its heat reclaimed with a heat exchanger.
5. Air Circulation.
The hot air is driven under the floor and forms a blanket that flows under the entire floor through to the perimeter registers. Half the heat is delivered convectively from the registers and half radiantly from the floor. The central return is at the highest point of the house collecting the stratified hot air and recycling it down through the floor. As with all hot air systems, all the air goes through one point and may therefore be filtered and humidified or dehumidified as well as heated or cooled.
6. Passive Solar Design.
The south façade is predominantly glass; the north, opaque. This minimizes heat losses to the north and allows the sun to shine in a heat up the floor. The floor mass prevents overheating and continues to release heat to the space through the night.
7. Interior Finishes.
The drywall utilized throughout is finished with latex paint and primer. Most major manufacturers have a line with minimal volatile organic compounds, some very sensitive people may require stricter control of paint finishes and can obtain milk-base paints and stains or finishes manufactured entirely with natural organic materials such as boiled linseed oil, shellac or tung oil. Heavy metals and VOC’s are carefully excluded by some manufacturers. The Masonite doors have a clear lacquer finish.
8. Exterior Finishes.
The roofing is “Ondura” by Ondura Corporation in Fredericksburg, VA/. It is asphalt-impregnated cellulose (with a high recycle content) and sports a lifetime warranty. It costs approximately the same installed as laminated shingle roofing. It may require resurfacing with a latex paint every 10-15 years.
The siding is Hardiplank, a composite material of sawdust and aerated autoclaved concrete. It is fireproof, rot-proof, and termite proof, and comes with a 50-year warranty.