Boston’s Building Energy Reporting and Disclosure Ordinance (BERDO)

3M Thinsulate Helps BERDO Compliance


Boston's goal is to be carbon neutral by 2050. In other words, Boston has pledged to reduce greenhouse gas emissions 100% by 2050. Given that buildings account for 70% of all of Boston’s GHG emissions, legislation was passed to require affected buildings be GHG-free by 2050. This legislation, titled Building Energy Reporting and Disclosure Ordinance (BERDO), is an ambitious program that brings attention to a building’s envelope efficiency in addition to lighting and HVAC.

Glass-intensive skyscrapers are a recent architectural trend – just take a look at any new construction. They look great, allow in a lot of natural light, and provide for fantastic city views. Despite the use of high efficiency glass, these building envelopes are energy inefficient overall because of the amount of glass that is incorporated into their curtainwalls.

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Why are all glass buildings generally energy inefficient?

It is because windows are generally inefficient. Look at what the U.S. Department of Energy has to say:

  • According to the DOE, the energy used to offset unwanted heat losses and gains through windows in residential and commercial buildings costs the United States $20 billion (25% of all the energy used for space heating and cooling)
  • According to the DOE, windows are responsible for as much as 30% of the total cooling load in commercial buildings

Even windows that are labeled high efficiency windows are more inefficient than other curtainwall building materials such as brick, limestone, concrete, metal panel systems, and the insulation and drywall that is behind them. As time passes and buildings make lighting and HVAC upgrades to reduce their carbon footprint, the inefficiency of vision and spandrel glass often go unaddressed.

Boston’s BERDO

The City government is putting pressure on building owners through BERDO to reduce their carbon footprint by addressing the inefficiency of the building envelope. Whether you have a building made of single pane glass, double pane glass, Low E glass, or high efficiency glass, glass heavy buildings often have an inefficient building envelope. There is great opportunity for energy savings and carbon footprint reduction by making existing windows more energy efficient.

80% GHG reduction by 2050

15% energy consumption reduction or 15-point increase in building’s Energy Star Portfolio Manager score.

3M Thinsulate Climate Control Window Film

3M Company, makers of Post-it Notes and Scotch Tape, can reduce the inefficiencies of an existing window with a retrofit product that we have been manufacturing for over 50 years – window film. The technology of window film has drastically evolved over these past 50 years to the point where an invisible retrofit film, known as 3M Thinsulate Climate Control 75, is almost the equivalent of window replacement. Installing it is almost like adding an additional pane of glass because it can reduce your existing window’s solar heat gain coefficient and U-Value, which allows your building to consume less energy to heat and cool twelve months out of the year. All without changing your building’s appearance, which makes BLC happy if the building is historical. (Be sure to check with BLC prior to any envelope changes.)


Compare that to actual window replacement, which is costly, disruptive to tenants, noisy, environmentally unfriendly as the old window units get thrown right into a landfill. Window replacement, especially if you’re converting from single pane glass to double pane or double pane glass to triple pane, adds a significant amount of weight to the building. There may be structural load implications that need to be considered.

But that’s not the case with 3M Thinsulate Climate Control 75. The installation process is cost-effective, quiet, and quick. And because we’re installing a plastic film to the glass rather than additional glass, there are no structural load implications.

Best of all, there are Property Assessed Clean Energy (PACE) funding programs in place to help property owners invest in capital improvements such as Thinsulate installation.

Just how effective is 3M Thinsulate Climate Control 75 Window Film?

Take a look at some performance characteristics of generic single and double pane window units.

What does all of this mean in plain English?

During the summer, when it is hot outside, much of the sun’s energy or heat is coming into a building through its glass. Part of the sun’s energy is reflected by the existing window, absorbed by the existing window, and what isn’t reflected or absorbed is transmitted, or enters the building. It is that transmitted energy that causes problems such as uncomfortable temperatures, the need for air conditioning, temperature imbalances, and glare. Applying window film increases the amount of the sun’s energy that is reflected and absorbed by the existing window, thereby decreasing what was transmitted. Decreasing the amount of energy that is transmitted, in other words, decreasing the amount of heat that enters the building, is what the film ultimately does.

During the winter, when it is cold outside and you’re running your heating system, much of that heat is escaping the building, especially through its glass. Window film reflects much of that heat back inside which means the room stays warmer and you use your heating system less.

Reducing solar heat gain in the summer and heat loss in the winter is what helps the building reduce its energy consumption, utility bills, and carbon footprint.

cooling season

What kind of temperature improvement can window film provide?


It’s one thing to talk about how 3M window film improves the efficiency of a window, it’s another thing to see and feel it for yourself. 

Here are the results of an experiment that was conducted during the cooling season (summer). Three identical, side by side, vacant rooms were identified in a building. The windows of two rooms were filmed while the third room was left untreated. The temperature of each room was taken and recorded in regular intervals over the course of a week. 

What you see here is that the two rooms with film were cooler than the room without film. During the hottest part of the day, that difference was as high as 9° Fahrenheit. In other experiments, it has been as high as 16°. Any facility engineer will tell you what a 4 -5° reduction means, let alone 9° or 16°. That means less tenant complaints, reduced energy costs, prolonged HVAC life, and a reduced carbon footprint. 


How do I know if 3M Thinsulate is right for my building?

We offer the following at no cost or obligation:
  • Product demonstrations
  • Sample installations
  • Calculate change in glass specs
  • Energy model assistance or completion
  • Assistance with rebate application
  • Assistance with PACE funding

3M Thinsulate Value Proposition

  • Increase efficiency of existing windows
  • 12-month utility savings (heating and cooling)
  • Reduce carbon footprint
  • Help achieve BERDO compliance
  • No change to building’s appearance
  • Rebates and PACE funding available
  • 15-year warranty


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