Such was the case with Dan Colombini, whose home in Ossining, New York was badly laid out, energy inefficient, in constant need of repair, and so poorly insulated that it would aggravate Colombini’s allergy-induced asthma.
But rather than simply move away, Colombini—a mechanical engineer and a principal at the New York City-based consulting engineer firm Goldman Copeland—decided to make lemonade out of his lemon of a house.
Working alongside a team of visionaries from Nugent Construction Management, CGA Studio Architects, and Restaino Design Landscape Architecture, Colombini personally engineered the home he wanted to live in. By the time construction was finished, that house had become one of the most energy-efficient and cost-effective houses in the country.
This dedication to energy efficiency makes the Colombini House the winner of Green Builder’s 2026 Green Home of the Year in the Net Zero Plus Energy category.
The Colombini House is an all-electric, net zero, U.S. Green Building Council (USGBC) LEED Platinum-rated “Passive House”—an architectural housing design that requires very little energy for space heating or cooling. Sustainable choices were made from the very moment of construction, with 75 percent of the original house’s materials being diverted from the landfill to be reused and repurposed within the new project, and the bulk of the remaining materials being recycled or locally sourced.
Initially, these decisions were made simply to achieve the goal shared by Colombini and his family of living in a net zero house. However, as the project continued, what initially seemed like faraway milestones rapidly grew more achievable.
“To achieve our net zero goals, research led us to the Passive House design strategy,” Colombini says. “During the design process, it became apparent that by following Passive House design criteria, LEED accreditation would also be within reach.”
By the end of the project, the home had achieved the LEED Platinum certification. Colombini would later note the team’s achievement of USGBC’s highest rating to be the most pleasant surprise of the project, considering it to be “icing on the cake” for having a healthy, comfortable, and highly efficient home.
Indeed, the Colombini House is more comfortable than it’s ever been. The three-bedroom, 3,500-square-foot home with attached garage is completely electric, thanks to its 18-kilowatt roof-mounted solar array. It is practically airtight due to its 12-inch-thick (18 inches on the roof) cellulose insulation cavity.
Energy efficient appliances add to the comfort while reducing the cost, from its Zehnder Energy Recovery Ventilator (ERV), to its Daikin 3-pump heating and cooling system, to its Rheem heat pump water heater, to its Vetta Elite92 windows and doors. In the event of a power outage, twin LG electric batteries will keep the fully LED lights on until normal service is restored.
The result is a house that produces far more energy than it uses—hence the net zero status. The difference is so great that Colombini can charge his electric vehicle off of the surplus power alone.
The project was not without its difficulties, however, the worst of which were all symptoms of a larger, more omnipresent struggle occurring during the time of building.
“As construction began in 2020, the effects of the COVID-19 pandemic were evident throughout,” Colombini recalls. “The project team was presented with hurdles related to material availability and cost, and labor availability.”
Other unwelcome surprises included difficult excavation, and delays resulting from need-to-order specialty products from Europe—most notably the aforementioned high-efficiency windows and doors—during a time when shipping was subject to frequent complications.
To combat these challenges, Colombini and his team tried to be as flexible as they could on material selection, and adjusted their task schedule based on labor availability. Coincidentally, these solutions would overlap with other project goals, including regionally sourcing materials such as wood for siding and flooring.
Colombini considers the build process to have been a valuable experience for all involved.
“One of the greatest challenges with Passive House and other high-performance construction is the lack of labor educated on the required methods and materials to be used,” he notes. “By executing this work, all stakeholders learned from the process and can carry these lessons forward to the next project to be completed.”
On the subject of value, however, there’s certainly a more-direct monetary benefit to the Colombini House as well. The cost of construction proved to be around $300 per square foot—only 8 percent higher than that of a traditional house. When compared to the energy savings it’s already begun to accrue, Colombini and lead architect Christina Griffin of CGA Studio expect the Colombini House to have paid for its marginally more-expensive construction within 10-15 years.
“The Colombini House is a landmark project,” Griffin says. “Not only does it reach the highest standards of energy efficiency and sustainability, but it demonstrates that they can be attained at an additional cost that can be recouped through energy savings in about a decade—far less than the period of a typical home mortgage.”
Colombini adds that there is little cost impact when it comes to achieving Passive House standards. “There’s a hope that broader education on the applied strategies can permeate throughout the construction industry,” he says. “There are always things that can be improved upon when looking back on any design and construction effort. That being said, we have no substantial regrets, and we appreciate the final product every day.”
Appliances: Bosch and LG appliances, all ENERGY STAR certified.
Building envelope: Exterior walls: 12-inch exterior Larsen Truss with dense-packed cellulose held by ProClima Mento 1000; 2-by-4 interior wall cavity with mineral wool batt. Ceilings have 1.5-inch Gutex continuous wood fiber insulation and 18-inch dense-packed cellulose, held by Intello wrap on the interior framing. Foundations insulated with XPS Rigid Foam.Cabinets, shelves, millwork: Custom millwork in the kitchen, bathrooms and mud room.
Caulks and sealants: Air sealing completed at OSB layer, with taped seams under the Larsen truss/cellulose layer. The home is within compliance of the Phius 2021 requirement of 0.06 CFM/SF of envelope area.
Countertops: Quartz countertops.
Decks: Front porch wood is locally sourced, thermally treated oak.
Doors and hardware: All doors (front entry, garage entry, patio sliding glass) sourced from Vetta Windows; high performance in line with Passive House strategy.
Electrical: Utility electric service is supplemented by an 18-kilowatt roof-mounted solar PV array. Two LG batteries in the garage provide emergency power during outages.
Exterior finishes: Regionally sourced hemlock wood siding is stained.
Fire protection: Smoke detection and fire extinguishers are provided per code.
Flooring: Regionally sourced hickory.
Garage doors: Insulated garage doors provided by Henry B Whitaker.
Home controls: Daikin controls provided for HVAC system, Zehnder controls for ventilation; occupancy sensor lighting controls are provided in closets.
HVAC/ducts: 3-ton Daikin heat pump system provides heating and cooling; Zehnder Energy Recovery Ventilator (ERV) provides ventilation.
Insulation: XPS Rigid Foam on foundations; 1.5-inch Gutex continuous wood fiber insulation and 18-inch dense-packed cellulose on ceilings.
Landscaping: In accordance with LEED requirements, all native plant species are used in landscaping; rain garden and bioswale with native plants provide a means for storm water management, mitigating runoff and promoting a healthy ecosystem.
Lighting: All LED fixtures.
Paints and stains: All zero-VOC paints from a variety of manufacturers.
Plumbing/plumbing fixtures: Variety of manufacturers.
Renewable energy systems (solar, wind, etc.): Utility electric service is supplemented by an 18-kilowatt roof-mounted solar photovoltaic array. Two LG batteries located in the garage provide emergency power during outages.
Roof: Architectural shingled roof for the main home, standing seam metal curved roof for the garage.
Telecommunications: Verizon carrier service feeds both wired and Wi-Fi service throughout the home.
Ventilation: Zehnder ERV provides fresh air supply and exhaust, recovering energy from exhaust air stream
Water heating: Rheem heat pump water heater operates at UEF of 3.88, provides cooling to the basement while generating hot water for domestic use.
Windows, skylights, patio doors: Vetta windows are used, with a predominant NFRC rating of U-Factor 0.17 and SHGC 0.49.
Other: Main stair handrail created by a local iron work artisan; EV charging is provided in the garage, supplied by the main electric/solar system.