Do you care about historic buildings?
If you don’t understand how contemporary insulation
practices damage historic building fabric, please read “Is Greener Always
Better? Problematic Use of Modern
Materials in Traditional Building Systems” (http://www.preservationconsultant.net/blog/-is-greener-always-better-problematic-use-of-modern-materials-in-traditional-building-systems). According to the article referenced above:
“The changes, proposed by a team of industry representatives
from the New Buildings Institute (NBI),the Natural Resources Defense Council
(NRDC), and the Institute for Market Transformation strip the exemption
language from the code. The group added a requirement that project teams
file a report with a code official when seeking immunity on specific areas of
the design or construction.”
Who are these organizations that made this recommendation?
According to their website, the New Buildings Institute “is a nonprofit organization working to
improve the energy performance of commercial buildings. We work collaboratively
with commercial building market players—governments, utilities, energy
efficiency advocates and building professionals—to remove barriers to energy
efficiency, including promoting advanced design practices, improved
technologies, public policies and programs that improve energy efficiency. We
also develop and offer guidance to individuals and organizations on designing
and constructing energy-efficient buildings through our Advanced Buildings®
suite of tools and resources.”
I didn’t see anything that indicates an understanding of
traditional building systems so I checked out the Natural Resources Defense Council’s website. Still nothing about old buildings. They’re an environmental action group whose
mission statement is “to safeguard the Earth: its people, its plants and
animals and the natural systems on which all life depends.” Admirable, but where’s the expertise
determining what’s right or wrong with energy conservation relative to older
That left just the Institute
for Market Transformation … would they be the ones with demonstrable
knowledge and expertise relative to traditional building systems? According to the website, they’re “a
Washington, DC-based nonprofit organization promoting energy efficiency, green
building and environmental protection in the United States and abroad. IMT's
work addresses market failures that inhibit investment in energy efficiency and
sustainability in the building sector.”
Lobbyists in DC! If historic
buildings are exempt from the IECC, this special interest group’s
sponsor/members can’t make any money selling the materials that the proposed
code changes will require.
Like so many things, this has nothing to do with right or
wrong: it’s about big businesses making money.
The Codes Council appointed three organizations who know nothing about
how green building practices will adversely impact traditional building systems
and destroy historic fabric. Why wasn’t
the Association for Preservation Technology or a similar entity included? Why?
Because the Council doesn’t want to hear what they have to say. Under the guise of energy conservation, those
who profit from “green” building practices are determined to cut into the
historic restoration market. The end result
will be the catastrophic loss of centuries-old buildings. What do they care? The ruined, old buildings will be razed and a
“green” one can take its place. Consider
this quote from the article:
“In Boston, for example, more than 8,000 properties are
either located in one of the city’s nine Historic Districts or are designated
as a local landmark, according to the Boston Landmarks Commission. For
Manhattan alone, New York’s Landmarks Preservation Commission lists 65 historic
districts; Kerr adds that approximately a quarter of all lots in that borough
Implementation of IECC 2015, in the proposed form, will be
disastrous. I implore everyone reading
this to spread the word. Will the NTHP,
MHC and other state SHPO’s lead the charge against elimination of the preservation
exemption? Perhaps, but we must all be leaders
and cannot rely on others to advocate against this change. This is our fight and the time is now.
When new words and terminology enter our vernacular, they
often take on a connotation larger and broader than they deserve. Today, “green” and “sustainable” are
synonymous with responsible living and construction, their meanings understood as
clearly by an architect or engineer as they are by the lay person. They are buzz words that make consumers feel
good about their purchases; they’re doing their part to protect the environment
and help save the world. But, in certain
applications, use of these terms is more than a misnomer; it’s outright false
Technological advances in building science have allowed for
the creation of the most energy efficient systems and materials that the
construction industry has ever seen.
With the ever rising cost of every fuel type, energy conservation is
always a high priority when planning for and designing buildings. Buildings, historically, are only as
efficient as the technology of the day allowed.
While we may shudder with the chill of a stiff breeze standing by the
window in an 1885 Queen Anne Victorian, imagine the relative level of comfort
that one of the Pilgrims would have enjoyed in the same situation!
Today’s building designers want to create watertight, airtight
structures that use minimal amounts of energy with windows sealed tight and
year-round climate control for maximum comfort.
They strive to design an envelope that needs low or no maintenance, fully
accepting that building owners will not care for their buildings as a
given. As far as new construction goes,
there’s no problem. In fact, this is
good news. But what happens when the
owners of older buildings want to implement these new technologies to increase the
efficiency of their buildings?
Older building stock tends to be far less efficient than
modern buildings. Wall systems and
joinery, windows and doors—they’re just not as tight. An unexpected benefit of these inefficiencies
is the passive ventilation that occurs, be it laterally through windows, doors
and walls, or by the “stack effect” in which warm air rises, bringing vapor
with it, escaping through the uninsulated roof system. Know this: older buildings breath. Modern building systems are designed so that
structures don’t breath and vapor is removed with dehumidifiers or other
mechanical forms of ventilation.
In older buildings, solid masonry walls rely on the
temperature gradient between interior conditioned spaces and the outside for
walls to drain properly. Insulating
these walls stops or mitigates the passage heat through the solid brick
masonry. This slows the drainage/drying
process and traps moisture vapor in the wall which, during freeze-thaw cycles,
freezes and expands up to 12% in volume.
Oftentimes the result is damage to the wall system of the envelope. Instead, the focus should be on controlling
moisture and preventing it from entering the wall system, both inside and out.
Today, older buildings have kitchens, bathrooms and laundry
spaces that they didn’t when first built.
This introduces a significant amount of moisture vapor that may enter
the wall system from the interior.
Installation of a vapor barrier will prevent this from occurring without
impacting the thermal effect that heated interior spaces have on the exterior
walls. Outside, mortar joints must be
kept tight and full. Penetrations such
as window and door jambs must be sealed tight where they abut masonry to
prevent water intrusion.
Roof drainage systems must be functional; gutters protect
and shed the walls from runoff and properly placed leaders direct the rainwater
away from the building at grade. It’s
also interesting to note that many older masonry buildings have large windows
resulting in a high window opening-to-wall surface area ratio. Improving the efficiency of the fenestration
through conservation and repair, as well as the addition of efficient interior or
exterior storm windows, will help preserve the historic integrity of the
building while also saving on energy costs.
Recently a client contacted me with questions and concerns
about insulating his masonry walls. He
was engaged in gutting much of the interior space in his circa 1870 brick
townhouse in a National Register historic district in Boston’s South End. The building department was demanding that he
insulate behind the walls in compliance with the International Energy Conservation
Code. When we pointed out that the code
specifically exempts buildings on or eligible for inclusion on state or
national historic registers, he said it didn’t matter if there was a lot of
interior gutting; that was his interpretation of the code. Only later, when a staff member from the
Boston Landmarks Commission intervened, was he straightened out.
Before you breath a sigh of relief, owners may have to prove
that their historic projects are worthy of exemptions from the International
Energy Conservation Code following changes to the forthcoming 2015 version
approved by the International Code Council last year. The changes were proposed by representatives
from the New Buildings Institute, the Natural Resources Defense Council and the
Institute for Market Transformation and they remove the exemption language from
the code. The group added a requirement that permit applicants file a report
with a code official when seeking immunity on specific areas of their project.
Do they sound like groups that know about old buildings? No, they don’t. They sound like groups that think LEED
certification matters when it comes to old buildings; you know, organizations
that don’t think full life cycle analysis matters in “green” building
practices. Why wouldn’t the team include
representatives from the Association for Preservation Technology or the
Preservation Trades Network? And,
frighteningly, who will train the code official that decides whether a project
receives an exemption or not? The answer
is NOBODY. So guess what happens when
you encounter our friend in Boston?
More and more I’m coming to believe that these people actually
hate old buildings. I’ve had arguments
with architects and contractors who wanted to spray closed-cell foam insulation
between the rafters under slate roofs.
Some specified removing all the slate and covering the roof with an ice
and water shield membrane then reinstalling the slate, effectively “sealing”
the roof tight. Besides being an unnecessary,
exorbitant extra cost, there’s a big problem with these grand, USGBC-inspired
plans: they actually destroy the
materials in a traditional roofing system.
Slate, clay tiles and wood shingles are traditionally fastened
to battens, skip sheathing or regular old boards—not plywood, no underlayments. The roofs are water tight, not air tight and
the building breaths through the roof.
Fiberglass insulation can improve energy efficiency and reduce heat loss
without preventing the roof from breathing.
Additionally, soffit and ridge ventilation can be added if desired. Traditional roof materials like slate, clay
tile and cedar shingles experience condensation. The passage of vapor helps dry things
out. When you stop the roof from breathing
everything stays wet.
Slate is comprised of thin layers of metamorphic rock that
delaminate and fall apart when they are kept damp for months. Clay tiles, like terra cotta and brick, will disintegrate. Wood shingles rot. Steel fasteners will experience corrosion and
fail. This has been the end of many a
slate roof; I’ve pulled the slates off the roof and seen it with my own
eyes. Cedar shingle roofs will last five
years, max, when installed on a solid roof deck covered in ice and water
shield. The reality is this: greener is
not always better, especially when wielded by those unfamiliar with traditional
building systems. “The greenest building
is the one already there” is a common expression in the historic preservation
world yet it’s never heard in “green building” circles. Go figure.