Historic Structures Deserve VIP Treatment

Restoration of historic buildings is tricky business. Among other challenges, preservation concerns severely limit façade alterations.

Restoration often includes deep energy retrofits which generally increase the thermal resistance (R-value) of the envelope. For existing structures adding insulation to the exterior is generally preferred over the interior as adding insulation from the inside will reduce its floor area. But for historic structures this approach is self-defeating.

Vacuum insulation has been used widely in non-building applications like refrigerators, thermos containers, and thermal doors. Its use in building envelope insulation is fairly new and still in R&D.  Vacuum Insulated Panels (VIPs) are composed of two stainless steel plates which sandwich a core of vacuum and fumed silica.

VIPs  possess 5-10 times the R-value of conventional insulation. Hence the thickness of wall sections may be far less than conventional insulation, effectively increasing the floor area. The resulting space savings alone are estimated to be $152 per foot of wall assuming a value of $182 per square foot of space.

Moreover, it has also been proven that the VIPs can add to the structural strength of the wall which then reduces the material necessary for structural members.

VIPs however are not perfect. Their stainless steel edges conduct heat, thereby reducing efficiency–though this has been largely mitigated by replacing its straight edges with serpentine ones. Other problems arise out of the panels’ fragility, allowing gases to enter its core and potentially rendering them useless. Gases will ultimately penetrate the VIP which limits their lifespan to less than 40 years.

VIP installations remain elusive owing to their high cost and a lack of proven history. Researchers believe these issues will be eliminated with enhanced technology and that VIPs will play a far more significant role in the future.

VOCs paint an ugly picture

Who doesn’t love the smell of fresh paint?  But, as so often seems the case, the good things in life are bad for us.

Green buildings transcend their structure and actually produce a positive effect on the health and comfort of their occupants. A key factor which determines this is the type of architectural coatings (paints, sealers etc.) and how many volatile organic compounds (VOCs) they contain.   Alas, these toxins are responsible for that wonderful fresh paint aroma.

VOCs are mainly used as solvents in coatings and contain aliphatic hydrocarbons, ethyl acetate, glycol ethers, acetone and formaldehyde.  In addition to being virtually unspellable, all of these have a very low boiling point slowly evaporate at room temperatures to be absorbed in to the human body. (Formaldehyde has a boiling point of -2F!) Low VOC coatings, by contrast, are those which contain water-based solvents.

Some of the harmful effects these VOC’s include irritation, headaches, loss of coordination, nausea, damage to liver, kidney, and central nervous system. Some are even suspected to cause cancer.

The EPA estimates that in a typical building the concentration of VOCs could be up to 5 times the concentration of outdoor air. In fresh paint this can be about 1000 times. In a society which spends most of our time indoors, the use of low VOC coatings can go a long way to reduce long term health risks and ensure comfort.

Convective Heat Loss, a sneaky villian

Strategies to increase building energy efficiency typically focus on increased efficiency of the HVAC system and increased thermal resistance of the envelope and fenestration.    An oft- overlooked, but vital, path to efficiency is reduction of air-leakage.

Heat transfer in buildings occurs in three forms: conduction, convection and radiation. Of these, conduction and convection transfer most of the heat. Conduction occurs when one body transfers its heat to another with which it is in contact–in this case, the transfer between interior and exterior air. Convection occurs when a heated body physically transports itself to another location. In this case air physically moving through leaks in the wall. Thermal insulation prevents conduction but does little to prevent convective heat losses.

The results of my research at Michigan State University for the US Department of Energy on Residential Energy Retrofit showed the tremendous impact leaks had on energy efficiency. The research revealed that in an average American home, the aggregation of these leaks is an equivalent of a 1 square foot hole in the wall!

How can air-leakage be controlled? The solution is surprisingly simple. First, an energy auditor must measure and detect air leakage. They may use several tests to determine this. The blower-door test is a common method used in small and medium sized buildings. Once detected, they may be removed by either using an air barrier or by caulking and sealing them. Additionally, the use of foam insulation in place of fiberglass acts as an air barrier by itself.

The US Department of Energy’s Guide on Air-Sealing has some really good information to how to effectively air seal a building.

Air-tightening the thermal envelope is one of the most overlooked strategies for energy efficiency, yet is one of the most important and cost effective.

How do you like them Apples?

Apple recently announced it will not certify its products with EPEAT. EPEAT is a non-profit organization that certifies “environmentally preferable products”. It is also a program that is backed by the U.S. Environmental Protection Agency.

EPEAT would affect Apple’s sales to some governments and educational institutions which require EPEAT certification as a prerequisite for purchase. But how does this affect Apple? According to the blog Apple and EPEAT: What it means the sale of Apple computers to government and educational institutions is a tiny fraction of Apple’s total sales. The real market lies in the consumer market which demands products like their ultra-thin MacBook Pro. According to a Wall Street Journal blog Apple Removes Green Electronics Certification From Products, this laptop design requires the battery to be glued to the case, making disassembly and recycling difficult. This causes the computer to fall behind EPACTS stringent recycling requirements.

But does parting ways with EPEAT mean Apple products are not green?  Hardly.

According to CNN Apple abandons green certification Apple meets Energy Star 5.2 requirements for energy efficiency and lead the pack in reporting each product’s greenhouse gas emissions on their website and removal of toxic material.  Yet all these achievements go unrecognized in the eyes of an inflexible rating system.

What does this mean for buildings? Are conventional environmental certifications constraining design and end-user needs that buildings need to meet to qualify? We think so.  That’s why SERF affords some flexibility and rewards innovation in green building certification.

LEED Eats its Young

LEED 2012 is just around the corner and, as expected, accessibility will plummet. According to a recent blog LEED 2012: Too much change? , by Allison Beer McKenzie many who were previously committed to LEED have decided to abandon it if the proposed changes are implemented.

What really are the proposed changes? Among the many, here are some I found to be most impractical:

The number of prerequisites will increase from 9 to 15.
SERF ‘s policy is that all of our points are fully fungible. Our applicants select which sections they desire to pursue and which ones make little practical sense to them. Prerequisites also make it practically impossible to perform a compliance evaluation post construction. LEED must now (more than ever) be on the agenda right from the conceptual phase of the project, hence increasing design costs.

Bike racks are now a prerequisite
This is curious as we routinely find this to be the most ridiculed credit in LEED . That it has been made a mandatory requirement suggests a certain disconnect with the marketplace. We recently met with the head of global real estate of a Fortune 500 consumer products company who complained about the impracticality of this credit required for their distribution centers located at freeway interchanges. He threw up his hands and said, “Our employees can’t bike on the freeway, and we wouldn’t let them if they could!”

Fundamental commissioning has been made more stringent. Example, roof assemblies now have to be commissioned
As mentioned in my previous blog Paying (and paying) for the LEED Label– a significant portion of the cost of LEED is related to documentation and third party consultant costs. This added stringency would further increase that cost.

The number of LEED professionals required in the team will be two instead of one in the 2009 version
Need I say more?

Additionally, demands related to other sections including energy efficiency and renewable energy have been raised by about 25% when compared to LEED 2009.

It seems very clear that LEED, which started off as a great market oriented rating system, intended to encourage decision makers to take the plunge into building green has now lost track of its original mission. The LEED clique will get smaller, albeit more “exclusive”, and will continue to drive adherents of Practical Environmental Stewardship to alternative certifications like SERF.

Paying (and paying) for the LEED Label

As mentioned in past blogs, the burdensome cost of LEED certification–measured in both time and money–lies in  consultant fees and documentation.  A very reliable study commissioned by the US General Services Administration (GSA) proves the point.

The GSA is an independent federal agency responsible for the construction, operation, and maintenance of federal facilities, including courthouses, office buildings, land ports of entry, and research facilities.

GSA commissioned this report to identify the incremental cost of LEED certification for two buildings: A new mid-rise federal Courthouse and a mid-rise federal office building modernization. The report analyzed both the incremental construction costs as well as soft costs–i.e. LEED-based documentation and consultation fees.

The incremental cost was calculated from a baseline construction cost for building to GSA’s  stringent guidelines. These guidelines required commissioning on all their buildings, higher energy efficiency than the code requirements, energy efficient underfloor air delivery systems and use of a large proportion of recycled materials in construction.

Given all these existing sustainable practices, the study showed that the additional consultation and documentation cost to be LEED certified was $112,412 for LEED Certified status up to high of $190,052 for LEED Gold status for the Courthouse Building. Similarly, the soft costs for the Office Modernization project was $106,716 for certified and $177, 328 for Gold.

Also according to the report, the soft costs as a percentage of the total construction costs will be significantly higher for buildings of smaller sizes than the buildings (260,000 to 300,000 square feet) in the study.

I wonder how much greener these buildings would have been if taxpayer dollars were invested in performance improvements rather than on consultant and documentation fees.