Greenwich Passive House Renovation
AIA CT Sustainable Architecture Award 2022
Our clients asked us to take an existing 1930s house on over four acres in Greenwich, CT, and transform it into a modern oasis. The goals for this project were not only to modernize a second home and haven for the young New York City family, but to create a gathering and entertainment place for friends, family, and kids to have fun. These desires - along with the clients’ sophisticated modern aesthetic - influenced the design significantly and led us, as architects, toward ‘breaking open’ the existing traditional structure to reveal spaces that are open, light-filled, and playful.
Given that our team - clients, architects, and builders - are all highly invested in sustainable building, our directive was also to turn this old leaky home into an energy efficient, sustainable one. We set our sights on achieving Net Zero and Passive House certifications (Both represent the most stringent energy efficient standards in the world.)
With the sustainability goal in mind, we gave ourselves the challenge of keeping as much of the existing house as possible. In the end, the house grew from 8,200 sf existing to 9,000 sf and we:
Did not add to the footprint.
Rebuilt part of the roof for a third-floor space including media room, bar and pool table.
Fully relocated the kitchen to the center of the house so that it could take full advantage of the private view and swimming pool access.
Created a dining room onto itself that is at once formal and fun enough for everyday use.
Created a spa like primary suite.
Gave every room a light filled, sculptural and spatially flowing atmosphere.
Ultimately, by embracing these challenges, we transformed a tired duckling into a peaceful, fun and lovely swan while also helping the planet.
SPECIFICATIONS
INSULATION - Energy Modelling led us to double stud walls with 10” thickness filled with mineral wool batts, in addition to 3” of continuous Comfortboard insulation; our typical wall assembly. Wall: R-52. The existing 2x12 roof was insulated with 6.5” of Demilec Heatlock Closed Cell Spray Foam and 4 3/4” of Dense Pack Cellulose. Roof 1: R-55. The new Roof was insulated with 18” of dense pack cellulose. Roof 2: R67. The basement walls was insulated with a combination Demilec Heatlock Closed Cell Spray Foam. 4” of EPS insulation board were placed over the existing slab-on-grade. Basement: R-25
ENVELOPE - A continuous air barrier, insulated window bucks and triple-pane European windows complete the energy efficient envelope.
BLOWER DOOR TEST - 0.6 ACH @ 50pa
ENERGY - The house is 100% electric (except for the gas stove in the kitchen and one gas fireplace.)
HVAC - Mitsubishi Heat Pumps heating and cooling, Sanden heat pump water heater, Zehnder ERVs and Make up air system comprise the houses mechanical systems.
SOLAR - Solar panels on the roof generate much of the home’s power needs.