Green Options » daylighting

Platinum LEED 19th Century Building

Philip Proefrock — Fri, 28 Mar 2008 04:50:52 +0000

Harvard University has achieved several firsts with the recent renovation of an old power plant into an office building. It is the first LEED Platinum certified university building renovation, as well as Harvard’s first Platinum building. More interestingly though, it is the first Platinum building built before the turn of the the century–last century, that is. Further, the university was able to complete this building without an increase in the up-front construction costs.

Better Daylighting

Philip Proefrock — Wed, 20 Jun 2007 14:45:26 +0000

solera : Image Credit: Advanced Glazings, Ltd.Lighting for buildings is a major part of their energy use. Increasingly, green building design is recognizing the importance of providing natural daylight as a means of lighting the building and reducing energy use. Not only does natural daylight reduce the building's energy use, but it also increases comfort for the people in the building. The LEED system includes credit for providing at least 75% of the spaces in the building with natural lighting and views, and the credit is increased if 90% of the spaces are naturally lit.

Windows are good for providing views to the exterior. Skylights can be used to bring in more daylight, but they are not without issues. The problem with skylights is that they tend to create glare. The high contrast between areas where the daylight is streaming through the windows and other parts of the space that are not directly lit is visually (and sometimes even literally) uncomfortable. There's either too much light or too little. Diffuse light is more even and comfortable, and avoids areas of deep shadow and sharp glare. This is why so many older buildings had north oriented skylights or clerestory windows (or south-oriented in the southern hemisphere), and why those spaces were so well thought of as artists' spaces and galleries. The light quality is much better when it is from an indirect source.

Most diffuser options do little to spread the light around. Typical etched or frosted glass has little effect. The light patterns are a little bit softer edged from frosted glass than they are from clear glass, but when it is directly lit, it is little better than clear glass. Advanced Glazings, Ltd. offers much better performance for incorporating daylighting into buildings with a line of insulated glazing called Solera. Architects have known of Kalwall, another company that has been making translucent panels for many years. Kalwall is a panel of polyester and fiberglass that offers translucency and some insulation.

Like Kalwall, Solera is principally a commercial product. However, it is designed for use in standard 1" aluminum window frames (what you find in many offices, stores, and other commercial locations). High end home projects and experimental uses in residential uses are sure to follow. Since there are many manufacturers of aluminum window frames, it is easy for an architect to incorporate Solera into a project without creating complexity for the builder to have to deal with. Contractors like to use standard products that they are familiar with. Solera is also appealing because it uses glass, rather than plastic, which tends to yellow over time.

Even more exciting than the daylighting aspect alone, a new Solera unit is coming out that incorporates nanogel insulation. The 3" thick glazing unit has a specially shaped edge that allows it to be installed in a standard 1" frame. But the window will have an R value of around 20! A standard double glazed window typically has an R value around 1. And a typical insulated 2 x 4 stud wall has an R value of around 15. (Kalwall also offers a nanogel unit.) For most buildings, the windows are the weakest part of the energy envelope, where the greatest amount of energy was lost. Incorporating well insulated diffusing windows and skylights into a high performance building would provide exceptional energy performance in addition to daylighting.

Green Building Tour: Genzyme Center

Philip Proefrock — Wed, 28 Mar 2007 12:54:35 +0000

The Genzyme Center in Cambridge, Massachusetts is in rare company. It is one of the fewer than 30 buildings on USGBC's list which has received a LEED Platinum rating, the highest level of the LEED rating system, indicating a building that has taken extraordinary steps towards sustainability, environmental responsibility, and energy efficiency. While the previous stop on our Green Building Tour, the Council House 2 (CH2) Building in Melbourne, Australia, wears it's green on its sleeve (or, perhaps more appropriately, its elevations) and has numerous external features that are part of its green character, the Genzyme Center is much more understated and, at first glance, looks much like yet another office building in Cambridge (though perhaps with more style than just another office building). The two buildings are alike, however, in that they are both at the leading edge of what is being done in their respective countries, but they approach that peak rating in very different ways.Genzyme Center is a 12 story office building with 344,000 square feet (32,000 square meters) and serves as office space for 920 employees of Genzyme. The building is owned by a property company and occupied by Genzyme as sole tenant.

Daylighting is a key to the building's design. The building is organized around a central atrium that makes the building incredibly open. All regularly occupied spaces in the building have views to the outside, and more than 75 percent of the "work spaces where critical tasks are performed" are naturally lit. The building supplements the skylights with heliostats, sun-tracking mirrors, which bring more daylight into the building throughout the day, especially in the winter when the sun is lower in the sky. A "chandelier" of mirrored panels is both a sculptural installation in the atrium and a functional element to diffuse sunlight throughout the building. The atrium also has a number of balconies with extensive plantings which project into the space at various levels, creating pleasant spaces with an almost outdoors feel.

Indoor air quality is also an important element in this building. Almost a third of the building is behind a two-layer window system that creates a thermal buffer between the building and the exterior, much like a very deep storm window. In summer, this space is ventilated to keep solar gain from building heat inside the building, while in winter this heat is captured and helps keep the building warm. Storage rooms for chemicals have a separate ventilation system, so that any fumes are not intermingled with building air. There are also operable windows on every floor, along with sensors that shut down the building HVAC to those spaces when the windows are open.All of these features do more than just make a pretty building. Natural lighting shows up on a balance sheet in the form of lower electrical bills for lighting. But outdoor views don't translate so immediately to a financial benefit, though there can be attempts to measure how it helps. A green building also makes a positive contribution to the wellbeing of its inhabitants.

The greening process in our design makes good sense all around. First, it offers direct operating savings. There is also a growing body of evidence that supports the theory that high-performance buildings are beneficial to employee health and productivity. While these costs and benefits are still in development, the potential for savings is significant. One report indicates that annual personnel costs vary from $300 to $500 per square foot. Therefore, a 1% increase in efficiency could be worth $3 to $5 per square foot. For Genzyme, this could average $1,040,000 per year in personnel efficiency alone. (USGBC)

Being in a LEED Platinum building has had positive benefits for Genzyme. Since moving into the building, the company has performed a number of studies and surveys of its employees to investigate this. Genzyme has found that their employees who work in the Genzyme Center had a 5% lower sick time rate than employees in their other Masachusetts facilities. That's the kind of real benefit that business types like to see to justify the added investment in building a green building. A more recent survey about the productivity of employees who work in the building found very positive impressions overall from the people who regularly work in the building.

"88% said having direct views and access to the interior gardens improved their sense of well being." "72% said they feel more alert and productive as a result of the lighting features in the building" "58% said having the ability to control the temperature of their workspace improved the quality of their work environment"

Genzyme is not taking this as a once-and-done PR step. Other facilities that Genzyme is creating are also following LEED (though not necessarily all to Platinum level). Rick Mattila, Genzyme Director of Environmental Affairs, told me "[W]e are seeking LEED certification for a fit-out of office space in a building adjacent to Genzyme Center in Cambridge. We did not construct this building. We simply leased it and converted it for our use. We have tried to apply what we have learned in constructing Genzyme Center to all facilities projects." This is the kind of lesson that LEED tries to pass along. The benefits of building greener are wide ranging. A green building is better for both the building owner, who gains financial benefits from the improved efficiencies, and for the building's inhabitants, who are happier and healthier and more productive.

The Genzyme Center building has received numerous awards, including an AIA/COTE Top Ten Green Project in 2004, and a RIBA Worldwide Award in 2005.

Building Information:Size: 344,000 sq ftLocation: Cambridge MALead design: Behnisch, Behnisch & Partner Architect, Venice CA. LEED-NC 2.0 Commercial Office, Platinum Rating

Sources:USGBC LEED Case StudyGenzyme Center Virtual Tour

Thanks to Jasmine Chng for providing Genzyme contacts and information