International Passive House Magazine Interview

iPHM Interview with Gregory Duncan, New York, USA

Written by Tamas Banki @ iPHM on 30 July 2011
Gregory Duncan
Gregory Duncan

Gregory Duncan’s interest in high performance building began while working on a deep energy retrofit to an office building in Hamburg, Germany in 1996. He returned to the United States to obtain a Master of Architecture degree at the University of Pennsylvania. Working in New York for over ten years, Mr. Duncan has acquired a significant amount of experience with building construction.

iPHM: Tell us about yourself.
Greg Duncan: My interest in high performance building began while working on a deep-energy retrofit to an office building in Hamburg, Germany in 1996. I returned to the United States to obtain a Master of Architecture degree at the University of Pennsylvania. Working in New York for over ten years, I have acquired a significant amount of experience with building construction. Complementing this practical experience, I continually pursue advanced training in the theory of green design and building science. I am a Registered Architect, LEED Accredited Professional and one of a select group of Certified Passive House Designers in New York State.

iPHM: What did you think that time about the Passive House?
Greg Duncan: I first heard about Passive House in an article in the German magazine Detail. I researched the standard further and discovered Jeremy Shannon’s blog about his townhouse project in Park Slope, Brooklyn.
I was impressed by the ability of the Passive House energy-modeling software to accurately quantify the energy savings in a building. I joined New York Passive House and am now a member of the executive committee.

iPHM: Are you a Certified Passive House Consultant (CPHC)? What does a CPHC do?
Greg Duncan: I became a Certified Passive House Consultant (CPHC) after taking the exam last year. The official designation from the Passive House Institute for CPHC’s who are also architects is Certified Passive House Designer – Architect. A Certified Passive House Designer uses the energy-modeling software PHPP to ensure that a building meets its energy target. As an architect I use my training and experience to design the building as a whole and all the details as part of the Passive House design process.

Your country

iPHM: How well known the Passive House standard in your country?
Greg Duncan:  Green building professionals are increasingly aware of the Passive House standard in the United States. In just a few years, this awareness has increased exponentially. The first wave of early-adopter homeowners shows by example how people in New York and the rest of the country can benefit from the Passive House standard.

iPHM: How many Passive Houses are there in your country?
Greg Duncan:  Nationally, there are dozens of completed Passive House buildings. There is currently one certified Passive House building in New York and almost a hundred under construction or in planning phases.

iPHM: Is there any subsidy in you country for the Passive House?
Greg Duncan:  There are many incentives for energy efficiency that a residential or commercial building that meets Passive House standards would qualify for.

Design/plan/develop

I have designed energy-efficient single-family, multifamily, and mixed-use buildings in and out of New York. I am now developing prototypes for Passive House multifamily buildings in New York City. I performed an energy analysis for a deep-energy retrofit of an historic carriage house being converted to office space at the Woods Hole Research Center in Massachusetts.

Passive House Ventilation

The Montessori School in Erding, near Munich, uses a very low amount of energy to heat because it is constructed to Passive House standards. Preconditioning the fresh ventilation air is one way the building achieves this high level of energy efficiency. The two ducts shown in the third picture above bring in preconditioned fresh air through earth tubes. While earth tubes use modern technology such as antimicrobial nano-silver coatings, the basic idea is nothing new. In Pecos, New Mexico the underground circular kiva ceremonial rooms used passive earth tube ventilation hundreds of years ago to provide fresh air.

Building owners should run ventilation air continuously through earth tubes to avoid mold growth. In Europe, where earth tubes are relatively common, there have not been significant problems with mold. However, many people in the United States are concerned that higher humidity—outside the Southwest, of course—could lead to mold problems if the earth tubes are not properly maintained.

Fortunately for owners in New York, earth tubes are not necessary to achieve the Passive House standard. Good insulation, air tightness, high-performance windows, and the proper orientation are enough.

Email architect@gduncan.us to learn more about building to the Passive House standard.

Open Revit Standards

A new project to develop free open standards for Revit building information modeling (BIM) software:  www.openrevitstandards.com.

A lot of time is spent reinventing the wheel to set up templates, lineweights, etc., in Revit, so join Open Revit Standards, contribute to the wiki, and post on Twitter using #OpenRevStds.