Energy Efficient Buildings

Energy Efficient Mountain Residence

Exterior walls of this home were constructed with R12 Continuous mineral fiber insulation and an air and weather tight membrane on the outside face of sheathing, R21 dense-pack cellulose insulation between studs, and an "Intelligent" air and vapor retarder membrane on the inside face of studs. Roofs received R60 insulation. A heat recovery ventilator exhausts stale air while efficiently conditioning incoming fresh air which provides a comfortable interior environment throughout the year.

Energy Efficient Mountain Residence

Exterior walls of this home were constructed with R12 Continuous mineral fiber insulation and an air and weather tight membrane on the outside face of sheathing, R21 dense-pack cellulose insulation between studs, and an "Intelligent" air and vapor retarder membrane on the inside face of studs. Roofs received R60 insulation. A heat recovery ventilator exhausts stale air while efficiently conditioning incoming fresh air which provides a comfortable interior environment throughout the year.

Larkspur Near Net-Zero Guest House Addition

The exterior walls of this guest house were constructed with double studs with R44 dense-pack cellulose insulation. Huber Zip-Wall Sheathing provides an air and weather tight exterior membrane, while an "Intelligent" air and moisture retarding membrane is on the inside face of studs and on the underside of roof framing. The roof is insulated with ten inches of dense-pack cellulose plus three inches of closed cell spray foam on the underside of the roof deck for a total of R55. A geothermal heating and cooling system utilizes a "Versatherm" snap-fit radiant floor heat system. A heat recovery ventilator provides balanced fresh air circulation throughout the house. Skylights provide ample solar heat and light for the sunroom / greenhouse wing.

Passive Solar House, Cherry Hills Village, CO

This caretaker’s residence was designed to make passive solar energy an integral part of the architecture. The glass-enclosed stairway serves as a primary solar collector. Its poured-in-place concrete stair cantilevers from a concrete support wall, with both the stair and wall clad in black tile to maximize absorption of the sun’s heat. The thermal mass of the concrete then stores this energy and releases it gradually. Heat collected within the stair enclosure is circulated to the upper level of the residence. When excess heat accumulates, operable skylights above the stairway open to provide natural ventilation. A Trombe wall on the south-facing wall of the lower level serves as a second passive solar collector. Solar heat absorbed and stored by the wall is circulated to both the main floor and basement. During the summer, motorized awnings shade both the stair enclosure and Trombe wall to prevent unwanted heat gain. Sun sensors automatically extend and retract the awnings as needed for effective heat management, while a wind sensor retracts them during high winds. The exterior materials and architectural character of the residence were selected to complement the Owner’s nearby home.

Passive Solar House, Cherry Hills Village, CO

The glass-enclosed stairway serves as a primary solar collector.

Cross Section Thru Heat Collecting Stairway

Architectural section detail illustrating construction of the passive solar-heated stairway, with glazed exterior wall, concrete thermal mass, ceramic tile surfaces, and roof construction.

Solar Heated House - Denver Country Club Neighborhood

While employed by James Sudler Associates Architects, Robert Larsen was a member of the design team for 180 High Street in Denver, one of the city’s earliest active solar residences. The house utilizes a hot-air solar collector integrated into the sloping south-facing roof. Solar energy heats air within the collector, which is then circulated through a large thermal-storage bin in the basement filled with egg-sized rocks. The rocks absorb and store the heat for later use. When the sun is not shining, the stored heat is drawn from the rock bed and circulated throughout the house. Solar energy is also used to help provide domestic hot water. To further reduce energy consumption, the house is highly insulated, with three inches of rigid foam insulation applied continuously to the exterior walls. The insulation is protected and finished with a synthetic stucco exterior, helping create a highly energy-efficient building envelope.

Solar Heated House - Denver Country Club Neighborhood

Together, the active solar heating system, thermal storage, solar-assisted domestic hot water, and enhanced insulation made this house an unusually forward-looking example of residential energy-efficient design for its time.

Solar Heated House - Floor Plan

Solar Heated House - Storing Heat

Diagram of a hot-air solar heating system showing roof-mounted collectors circulating heated air to a basement rock storage bed, with a fan and backup gas furnace.

Solar Heated House - Heating From Collector

Diagram of a hot-air solar heating system showing heated air circulating from roof-mounted solar collectors through the house, with basement rock heat storage and a backup gas furnace.

Solar Heated House - Heating From Storage

Diagram of a hot-air solar heating system showing stored heat being drawn from the basement rock storage bed and circulated through the house, with a backup gas furnace.

Solar Heated House - Summer Hot Water Storage

Diagram of a hot-air solar system in summer mode showing solar collector heat used to heat domestic hot water while excess heated air is exhausted outdoors.