Category: passive house

24 May

Success with Passive House: An Interview with Ryan Cassidy

Leyna O'Neill enterprisegreencommunities, insulation, passive house

Ridgewood Bushwick Senior Citizens Council (RBSCC) is leading the way for new construction in the affordable housing market with their dedication to high efficiency building practices, and more specifically, the Passive House Standard to which their properties,  Knickerbocker Commons and Mennonite United Revival Apartments, were built. After noticing these properties’ incredible performance in EnergyScoreCards, Bright Power sat down with RBSCC Director of Property & Construction Management, Ryan Cassidy, to discuss his experiences with Passive House.

Not familiar with Passive House? Check out our breakdown “What is Passive House and Why You Should Care”.

The following has been lightly edited for clarity.

LO: At what point did Passive House land on RBSCC’s radar?
RC: In about 2004 we started working with NYSERDA’s Multifamily Performance Program (MPP) and we saw that the incentives available for high efficiency buildings were substantial, and it was cutting edge at the time. A few years later we noticed that the available grant money was decreasing but there was an uptick in consultants who could administer the MPP program so we started looking for ways to construct buildings that were really geared toward energy savings. We got in touch with Chris Benedict [architect at Chris Benedict R.A.] who presented the idea of constructing a Passive House. It wasn’t something we were familiar with at the time, but Chris had extensive experience in energy efficient buildings so we were interested in her ideas.

LO: What was the motivation for going forward with Passive House at Knickerbocker Commons and Mennonite United Revival Apartments?
RC: Knickerbocker Commons was the first Passive House building we designed, though it ended up being built second due to a lengthy design approval process. The reason we stuck with it through all of that was because the design showed us that we could build the same building type for the same cost, but with significantly more efficiency. The numbers showed that we could have boiler systems and heating plant distribution that were one third of the typical size and then allocate those savings toward the insulation and ventilation. We went through the same process at Mennonite United Revival Apartments, though it got approved a little faster.

LO: So it was a combination of both cost-effectiveness and high efficiency that drove you?
RC: Yes, it works so well in affordable housing because our rents are so stabilized and we’re unable to implement big rent increases, but we can make up that difference on the operations and maintenance side with high efficiency design.

LO: Did you find any overlap between Passive House design consulting and Enterprise Green Communities (EGC)?
RC: Since it was an affordable housing project, we had to go through EGC and there was a lot of overlap between the two but Passive House goes above and beyond by focusing on performance. That’s another thing that really drew us to Passive House, it’s quantifiable. Anyone can specify a high efficiency boiler but if it’s not installed correctly, you’re not going to get the results. We were much more comfortable with the Passive House standard because it’s more results-driven.

LO: How cost-effective was Passive House construction and how did that compare to the cost of a typical new construction project?
RC: I think what separates Passive House projects from a lot of other efficiency projects is that you can deliver the building at the same cost, and that’s hard and soft costs, as a typical new construction project. It was even an easier sell to the funding agencies because it wasn’t going to cost anything extra.

LO: Can you talk about the incentives that were available to you?
RC: There were some NYSERDA incentives available but we didn’t go all the way with them because we really wanted to show that the design was our main driver, not programs. We wanted to show that we didn’t need additional funding streams to build a highly efficient building.

LO: How has the energy performance of the Passive House buildings compared to the non-Passive House projects you’ve done? We’ve seen the analysis in EnergyScoreCards but we’d love to get your take.
RC: If we didn’t have EnergyScoreCards I don’t know how we would’ve been able to represent that we actually hit our marks on this. We’re seeing major savings, 80% to underwriting, for the same cost as typical construction. Next, we’re looking for ways to push the envelope even further. How can solar fit into lowering energy consumption at a building even more? Now that we’re comfortable with the way these buildings are performing, we’re working with HPD, HCR and groups like Enterprise to make this accessible to anyone who’s building in the City. We think everyone should be building this way and we think everyone can build this way.

The above graph, pulled from EnergyScoreCards, shows significantly lower energy indexes at RBSCC’s Passive House properties Knickerbocker Commons and Mennonite United Revival Apartments (shown in orange), compared to non-Passive House buildings (shown in blue).

LO: What changes would be effective in getting more passive houses built in New York City?
RC: I would say it’s related to performance. There are people that say they’re producing high performance buildings but are they actually getting the results? I was at a the quarterly Carbon Challenge meeting today and the sustainability department there said that typically we are constructing new buildings with the same efficiency as 30 or 40 years ago. To me, that’s the same as producing a Chevy 350 today in the same way that you would in 1970. We need to make sure we’re in buildings that reflect the technology that we have available. It’s not about getting your LEED sticker, and frankly, it’s not even about getting your Passive House certification. Building with the means and methods to produce efficient buildings, that’s really what we care about.

LO: What kind of feedback have you gotten from the residents of your Passive House buildings?
RC: I’d say there’s a learning curve. In the beginning people would complain that they didn’t have heat, but the super would go into the unit and see that it was 72 degrees. What they meant was that their baseboard wasn’t hot. They’re used to thinking that if the baseboard isn’t on, that means they don’t have heat, but because the building is so well-insulated, the apartment is comfortable without the baseboard heating being on. Now people understand that the temperature is balanced, no hot spots around the baseboards or cold spots above the windows. The number one thing we get compliments on is the ventilation. The cooking smells and smoke don’t travel to other units because there’s no stack. It’s also nice that there’s not a lot of technology associated with Passive House. There’s no complicated thermostat or anything that the residents need to know how to use.

LO: I think I know the answer to this one, but will you be building to the Passive House standard in the future?
RC: Yes. Before we started this I said if we can get this to work, this is the only way we should be building. Like I said, it’s not really even about the certification, it’s about understanding the means and methods of high efficiency buildings. That’s what concerns us as owners. We really want to build to that standard on every project, even now with renovations. It’s especially important in New York City where most of the housing that will be built, has already been built. We need to make sure our existing housing stock is energy efficient so we’re going to build to this standard and try to renovate to this standard and hopefully get to net zero in the future.

22 Feb

What is Passive House and Why You Should Care

Leyna O'Neill efficiency, energy, passive house


Passive House, or PassivHaus as you may have seen it written, is an innovative new approach to energy efficient design and construction practices.  We’re excited to see it popping up across the United States more and more. There are plenty of well-covered examples of these projects – their potential impact on residential energy conservation efforts is unmatched.  But what are people really talking about when they say Passive House? And more importantly, should you be considering it for your next development?

What is Passive House?

Passive House is a recently-developed German building standard that takes energy efficiency to the next level.* Buildings that are designed to this standard are called “Passive Houses,” but they aren’t just single family homes. Passive Houses can include multifamily and commercial developments, too.    

Passive Houses require less energy to heat and cool, and are up to 90% more efficient than the existing building stock. Insulation and superior air sealing are the primary focus of Passive House design.  The goal is to design an extremely air-tight building envelope, limiting outside air coming into the building. This allows for the ventilation to be managed mechanically, which dramatically improves indoor air quality without consuming unnecessary energy.

What are the benefits?

Passive Houses are built to exceptional standards, and the benefits follow suit. The fine-tuned control over indoor air quality and temperature make Passive Houses extremely comfortable for residents throughout changing seasons and across climates. An added perk of the focus on insulation is that they are also much more sound-proof than traditional buildings – something our friends in NYC and other bustling cities across the country certainly covet.

Additionally, Passive House is a smart financial investment. Because the buildings are so well insulated, their heating and cooling systems can be dramatically smaller, which helps offset some of the costs of higher quality envelope.  The highly efficient design reduces energy usage and operating costs dramatically, making up any additional construction cost within a few years.   

And, of course, these buildings are good for the environment.

How do I know if it makes sense for me?

While existing buildings can be retrofitted to these standards, Passive House is most common for newly constructed single family homes, multifamily buildings, and commercial real estate developments. If you have an upcoming construction project, Passive House is an excellent option to explore if you want to maximize comfort and minimize utility costs. The key is to incorporate it into the design process as early as possible for an easier transition to high-performance design.


*There are several different standards by which to certify a building as Passive House, (e.g. Passive House International and Passive House US) but the philosophy and intent is similar.