The Preservation League of New York State has selected a consultant to identify insulation strategies for two historic buildings located in Washington and Greene Counties in New York.

EYP Architecture & Engineering, based in Albany, will complete the study in three phases: engineering and analysis; installation of selected insulation material; and a final report outlining results observed.

The project team will consist of Bob Kennedy as Director of Energy Services, Mark Thaler as Principal and Historic Preservation Specialist, Scott Janssen and Kristin Gustafson as Energy Analysts.

“EYP is uniquely positioned to provide these services due to our ability to take a project from a feasibility concept straight to construction,” said Kennedy. “EYP’s combination of in house Preservation architects, Engineers, Energy specialists and Construction Administration personnel will allow the Preservation League of New York the ability to benefit from a full range of expertise in a single contract.”

The goals of the project are to identify insulation strategies appropriate to historic buildings that adhere to the Secretary of the Interior’s Standards for Rehabilitation, minimize the impact on the historic character of the subject buildings, and address the issue of condensation.

Funding for this project is provided by the New York State Energy Research and Development Authority’s (NYSERDA) Energy Code Training Program and the National Center for Preservation Technology and Training (NCPTT).

According to the National Trust for Historic Preservation, many older and historic homes were not designed with insulation, so great care must be taken to select compatible insulating systems and materials. Older buildings, or those built before modern HVAC systems existed, were actually built to deal with the movement of air naturally through special design features. If a building was constructed before 1950, careful consideration must be given to the addition of insulation.

“One of the most common problems arising in appropriate insulation is condensation, which can lead to peeling paint and dangerous mold and mildew,” said Jay DiLorenzo, president of the Preservation League. “Issues like these are becoming more prevalent as older buildings are insulated to enhance energy efficiency. As a result of this study, the League hopes to provide specific guidance to building owners and contribute to New York State policy associated with energy upgrades of existing buildings.”

“I’ve been insulating old homes for over 30 years and I’ve never left a project without insulating the walls.”

Gary, our insulation contractor, and I stand in my kitchen, discussing our project. Several weeks ago, my husband and I had our home energy-audited through a NYSERDA program. Now, as part of NYSERDA’s Green Jobs Initiative, we decided to implement some of those recommendations. As circumstances had it, I am deep in the midst of the Preservation League’s “Energy Conservation in Historic Buildings” program delivery, having spent the last six months absorbed in theories about wall insulation, air sealing and closed v. open cell systems. A little bit of knowledge is a dangerous thing. I have just enough to understand how very little I know about building systems and related building science. I do know, however, that the jury is very much still out when it comes to questions of wall insulation in pre-World War II buildings.

As a historic preservationist, I feel very comfortable advocating for the retention of historic wood windows. Several studies[1] back up my belief that replacing old windows is not the answer to achieving optimum energy efficiency in one’s home. I made this clear to Gary on the day he performed our energy audit. Of course, Gary didn’t recommend replacing my windows, because he knows that it doesn’t bring the most “bang for your buck” in an energy efficiency retrofit.

But, when it comes to insulation, I am on shakier ground. Through the series of over a dozen interviews with architects, engineers, and building scientists leading to the development of the League’s “Energy Conservation in Historic Buildings” curriculum, the biggest issue each and every one raised had nothing to do with windows and everything to do with insulation. Where to insulate. What type of insulation to use. How to keep a building’s historic details intact during insulation. Nobody had the answer, but everybody agreed it was a question.

Now I am standing in the kitchen of my 1920s center-hall colonial, speaking with a contractor making a very strong (not to mention pricey) set of recommendations that impact my home, my finances and my family. My husband, understanding the set of questions involved with wall insulation, read some of the same materials I had and agreed that it was not a clear-cut issue. Together, we made the decision to leave the walls empty. The original plaster remains on our walls and through the two winters we have spent there, we have never felt chilled from being close to the walls. Of course, we also make a point of not keeping furniture up against exterior walls in the winter.

We did follow some of the energy auditor’s recommendations – to insulate the ceiling of our finished attic, as well as air seal between our foundation sill and the walls, better seal our exhaust fans and weatherstrip our exterior doors. Documents like this helped inform that decision.

Gary is talking to me about all of the old houses he has insulated over his career and what a difference the wall insulation made in the comfort of those homes. I do not question that insulation matters to a house’s energy conservation, but I do wonder whether the vast majority of impact was in the roof insulation and air sealing, most often done at the same time as the walls, making it difficult to distinguish between it and the rest of the project. So we’ve decided to test this theory on our own house, partly out of concern for the fresh coat of paint we just put on our exterior clapboard, partly out of interest in preserving our interior plaster, partly out of concern for mold, and only slightly out of curiosity whether the interventions we chose will have a significant impact on their own.

Postscript: A month has passed since we had the cellulose insulation blown into our attic ceiling and along the crawl spaces and knee walls in our finished attic. We had a significant heat wave within that month and already could feel the difference in the attic space and throughout the house, which all remained relatively cool.

[1] Studies on the energy efficiency of historic wood double-hung windows often focus on the installation of storm windows, as well as weather-stripping and/or retrofitting, in order to make them at least as efficient as a modern vinyl double-glazed window. Studies are listed in reverse chronological order below:

Kinney, Larry and Amy Ellsworth.  “THE EFFECTS OF ENERGY EFFICIENCY TREATMENTS

ON HISTORIC WINDOWS.” The Center for ReSource Conservation. Boulder, CO, 24 January 2011. http://www.conservationcenter.org/assets/EffectsEnergyonHistoricWindows.pdf.

Klems, J. H. “MEASURED WINTER PERFORMANCE OF STORM WINDOWS”  Windows and Daylighting Group, Building Technologies Department Lawrence Berkeley National Laboratory. Berkeley, CA, 2003. http://www.parks.ca.gov/pages/1054/files/berkeley%20storm%20window%20research.pdf.

James, Brad, Andrew Shapiro, Steve Flanders, Dr. David Hemenway. “Testing the Energy Performance of Wood Windows in Cold Climates — A Report to The State of Vermont Division for Historic Preservation, Agency of Commerce and Community Development (1996-08)” National Center for Preservation Technology and Training, 30 August 1996. http://ncptt.nps.gov/2008/testing-the-energy-performance-of-wood-windows-in-cold-climates-a-report-to-the-state-of-vermont-division-for-historic-preservation-agency-of-commerce-and-community-development-1996-08/.