Oppositions in Green Building -- Glass vs. Mass
The Urban Green Council (NY Chapter of U S Green Building Council) has started a new quarterly series of panel discussions on controversial issues in the green building area. Last Wednesday evening, I had the opportunity to attend the first in this timely and informative series.
The topic covered was Glass vs. Mass. Specifically, this refers to the use of large amounts of glazing for the make of the building envelope, as opposed to less than 40 percent of fenestration, which was common in pre-World War II buildings. A panel of six was assembled -- two building owners or managers, two engineers, and two architects, along with a moderator.
Prior to the start of the discussion. Lauri Kerr from Mayor Bloomberg's Office gave a brief history of the how glass became more prevalent in building design. She focused on six areas, with the most important being the widespread availability of cheaply mass-produced sheets of glass beginning with time period coinciding with the building of Versailles during the 17th century. As we know, this was a tribute to the Sun King, and features an entire Hall of expansive glass, the Hall of Mirrors. Monet further influenced the use of glass, as he emphasized color and light to the environment. By the 1920's early modern architects began to use more glass in their designs. However it was really after World War II and the availability of cheap, mass produced large panes of glass,combined with inexpensive fuel, that we really saw glass become the predominant feature of many building facades.
The main concern with the extensive use of glass, even with improved glazing technology, continues to be that of heat gain and loss. Nonetheless, people are drawn to buildings that have large amounts of glass, as they create a feel of freedom, democracy, allow for the connection to the outdoor environment, and above all, provide for natural daylighting.
Thus, the use of glass is has clearly been market driven, as customers have insisted that architects use it extensively. It sells a building.
Charles Linn, Deputy Editor of Architectural Record (which I subscribe to) served as moderator. His first two panelists were J. Christopher Daley (pro glass) from River House Projects, and Anthony Malkin, President of W & M Properties (pro mass) -- owner of the Empire State Building.
Anthony Malkin felt that the large use of glass was bad, and preferred to concentrate on the pre-World War II design, as it offered the tenant more wall space and better control over glare and interior use of the space. He does admit that glass has been market driven, and depends on location.
Mr. Daley, on the other hand, looked at the quality of light brought into a building as being a factor in tenant satisfaction. He also feels that it contributes to the longevity or life-cycle of the building, as tenants will see it desirable over a longer period of time. Mr. Daley went on to emphasize the improvements in glazing technology, such as triple glazing with argon or krypton gas fill, that has dramatically improved the R-Value of glazing from the single or even double pane Thermopane of the past. He also said that location plays a big role in the choice of mass vs. glass, as well as the ability to get a better R-Value incorporated into the design. This is especially important during the short term, but payoff time can be long. Mr. Daley said that it is possible to achieve LEED Platinum Certification with relatively large amounts of glass if one balances the energy loads carefully, but the initial costs are often NOT recovered.
Mr. Malkin did mention that the Empire State Building is currently undertaking a massive retrofit of its existing Thermopane windows to incorporate this new technology. In addition, other energy saving efforts, such as radiator reflectors, and improved lighting efficiency. The aim here is to achieve LEED Gold Certification for Existing Buildings. (E
They are expecting a 38% reduction in energy use. He is also building a project in Connecticut that will be LEED Platinum Certified, and will combine glass and mass. In this building, he will use a curtain wall, so that some mass will be used to reduce construction and operation costs.
On the other hand, Mr. Daley is using a green-house effect to achieve efficiency, in which an outside glass barrier will be placed on the exterior envelope wall to receive heat during the winter, and come summer, this can be ventilated to reduce heat gain. This third pain of glass, set eight inches out from the primary envelope wall, thus allows for an additional barrier, while being operable, allows for natural ventilation.
Mr. Malkin feels that mass reduced the heat effect in the Empire State Building. This can realized by several examples given where large glass sided buildings have actually been shown to reflect the heat in much same fashion as that of a mirror, to an adjacent building.
The second pair of panelist represented the engineering part of the issue, and included a facilities manager (Mr. Houshmound) and Scott Frank, partner with Jaros, Baum and Bolles. Mr. Frank is pro-mass.
Mr. Houshmound feels that the problem with glass is that many buildings still have 50-plus year old glazing technology (many with just clear single pane glass) and this can be drastically improved on by using new technologies such as those mentioned above -- triple gas-filled glazing, low-e coatings, and heat mirror design. He feels that this has happened due to cheap fuel costs during the 1950' and 1960's.
Mr. Frank, who is pro-mass, feels that building envelopes must be made more energy efficient than even the best gazing technology can provide, and the Human Comfort Factor will become more of an issue, as fuel costs rise. In addition, he mentions the vision comfort issue as well; large areas of glazing can often create glare issues.
Mr. Houshmound feels that this all market driven in NYC, but climate issues need to be taken into account.
Mr. Frank said that even with improved R-Values of glazing, the use of more mass in the building envelope will always lead to lower A/C costs. He does admit that triple glazing with gas fill can improve the R-Value by 50%, from that of standard double glazing. He also feels that the costs of this new technology will be absorbed by lower production costs as demand creates more manufacturing of these innovative glazing products.
When asked about the role of codes dictating the direction here, both panelists agreed that this will be an effective means.
Mr. Houshmound mentioned the use of switchable glazing, in which phase-changing materials, controlled by electrostatic charges, are incorporated into the glazing system. These can be used to reduce glare issues and solar gain. He does admit that fuel costs will be the ultimate dictator in the choice as to whether to use large amounts of glass or more mass.
The final two panelists were from the architectural area. They were Robert Whitlock, Principal, Kohn Pedersen Fox Associates (pro-mass) and Stephan Cassell, Principal, Architectural Research Office.
Mr. Whitlock, while pro-mass, likes the idea of sun shading and light shelves, and feels the need to create a building that incorporates the biological needs of the surroundings, while bringing in daylighting.
Mr. Cassell feels that the lower floors can be all glass to create an open feel but does admit that glass use must be executed properly and there is need to incorporate some strategic use of mass, such as a spandral wall. Thus, the need to combine mass with technology.
A discussion along question and answer period followed the presenters.
The first item taken up was that of codes. Here, it was mentioned that already we have seen the outlawing of monolithic glass in Hong Kong.
Sub-metering has was also mentioned as a means of controlling energy use, as most buildings in NYC include utilities in the base rent.
Over designing, as required by certain codes, was mentioned, and it was fully agreed that this must be drastically cut back. For example many codes require the provision of as much as eight watts per square foot of space, where newer technologies in lighting and office equipment can reduce this need by more than half, in some cases to under two watts per square foot.
Another fact pointed out was that many facades do NOT meet the codes by themselves, but when combined with increased efficiencies in A/C and other building components, the overall code is met. In order for codes to be fully accepted by the public, they need to incorporate incentives to do better.
One member of the audience asked about the use of blower door tests. From the panel, it appears that they are not common place everywhere. A blower door test will confirm how much infiltration is present in the building envelope. This is important at the immediate completion of construction, and later on, as glazing settings, especially liquid silicone, can deteriorate over a period time, and leak large amounts of air around the glazing system in and out of the building.
Another audience member felt that additional power plants should NOT be built to allow for more glass use. The panelist responded by emphasizing the improvements in glazing technology.
The use of thermo gels was also asked about,but the panelists said that they are ineffective, as they tend to discolor drastically.
I asked whether it might be practical to incorporate the use of thermal storage techniques to store the heat gain taken in during the daytime in winter, and use it during the night hours. In addition, I asked if this heat could be harvested during the summer to produce domestic hot water by use of heat pump technology from the air conditioning process already in use. One could simply cool the compressor with incoming domestic water, providing free hot water for the building to use. The panelist did not feel that, at this point, that we could do this in a cost effective manner. More research is needed here.
The topic covered was Glass vs. Mass. Specifically, this refers to the use of large amounts of glazing for the make of the building envelope, as opposed to less than 40 percent of fenestration, which was common in pre-World War II buildings. A panel of six was assembled -- two building owners or managers, two engineers, and two architects, along with a moderator.
Prior to the start of the discussion. Lauri Kerr from Mayor Bloomberg's Office gave a brief history of the how glass became more prevalent in building design. She focused on six areas, with the most important being the widespread availability of cheaply mass-produced sheets of glass beginning with time period coinciding with the building of Versailles during the 17th century. As we know, this was a tribute to the Sun King, and features an entire Hall of expansive glass, the Hall of Mirrors. Monet further influenced the use of glass, as he emphasized color and light to the environment. By the 1920's early modern architects began to use more glass in their designs. However it was really after World War II and the availability of cheap, mass produced large panes of glass,combined with inexpensive fuel, that we really saw glass become the predominant feature of many building facades.
The main concern with the extensive use of glass, even with improved glazing technology, continues to be that of heat gain and loss. Nonetheless, people are drawn to buildings that have large amounts of glass, as they create a feel of freedom, democracy, allow for the connection to the outdoor environment, and above all, provide for natural daylighting.
Thus, the use of glass is has clearly been market driven, as customers have insisted that architects use it extensively. It sells a building.
Charles Linn, Deputy Editor of Architectural Record (which I subscribe to) served as moderator. His first two panelists were J. Christopher Daley (pro glass) from River House Projects, and Anthony Malkin, President of W & M Properties (pro mass) -- owner of the Empire State Building.
Anthony Malkin felt that the large use of glass was bad, and preferred to concentrate on the pre-World War II design, as it offered the tenant more wall space and better control over glare and interior use of the space. He does admit that glass has been market driven, and depends on location.
Mr. Daley, on the other hand, looked at the quality of light brought into a building as being a factor in tenant satisfaction. He also feels that it contributes to the longevity or life-cycle of the building, as tenants will see it desirable over a longer period of time. Mr. Daley went on to emphasize the improvements in glazing technology, such as triple glazing with argon or krypton gas fill, that has dramatically improved the R-Value of glazing from the single or even double pane Thermopane of the past. He also said that location plays a big role in the choice of mass vs. glass, as well as the ability to get a better R-Value incorporated into the design. This is especially important during the short term, but payoff time can be long. Mr. Daley said that it is possible to achieve LEED Platinum Certification with relatively large amounts of glass if one balances the energy loads carefully, but the initial costs are often NOT recovered.
Mr. Malkin did mention that the Empire State Building is currently undertaking a massive retrofit of its existing Thermopane windows to incorporate this new technology. In addition, other energy saving efforts, such as radiator reflectors, and improved lighting efficiency. The aim here is to achieve LEED Gold Certification for Existing Buildings. (E
They are expecting a 38% reduction in energy use. He is also building a project in Connecticut that will be LEED Platinum Certified, and will combine glass and mass. In this building, he will use a curtain wall, so that some mass will be used to reduce construction and operation costs.On the other hand, Mr. Daley is using a green-house effect to achieve efficiency, in which an outside glass barrier will be placed on the exterior envelope wall to receive heat during the winter, and come summer, this can be ventilated to reduce heat gain. This third pain of glass, set eight inches out from the primary envelope wall, thus allows for an additional barrier, while being operable, allows for natural ventilation.
Mr. Malkin feels that mass reduced the heat effect in the Empire State Building. This can realized by several examples given where large glass sided buildings have actually been shown to reflect the heat in much same fashion as that of a mirror, to an adjacent building.
The second pair of panelist represented the engineering part of the issue, and included a facilities manager (Mr. Houshmound) and Scott Frank, partner with Jaros, Baum and Bolles. Mr. Frank is pro-mass.
Mr. Houshmound feels that the problem with glass is that many buildings still have 50-plus year old glazing technology (many with just clear single pane glass) and this can be drastically improved on by using new technologies such as those mentioned above -- triple gas-filled glazing, low-e coatings, and heat mirror design. He feels that this has happened due to cheap fuel costs during the 1950' and 1960's.
Mr. Frank, who is pro-mass, feels that building envelopes must be made more energy efficient than even the best gazing technology can provide, and the Human Comfort Factor will become more of an issue, as fuel costs rise. In addition, he mentions the vision comfort issue as well; large areas of glazing can often create glare issues.
Mr. Houshmound feels that this all market driven in NYC, but climate issues need to be taken into account.
Mr. Frank said that even with improved R-Values of glazing, the use of more mass in the building envelope will always lead to lower A/C costs. He does admit that triple glazing with gas fill can improve the R-Value by 50%, from that of standard double glazing. He also feels that the costs of this new technology will be absorbed by lower production costs as demand creates more manufacturing of these innovative glazing products.
When asked about the role of codes dictating the direction here, both panelists agreed that this will be an effective means.
Mr. Houshmound mentioned the use of switchable glazing, in which phase-changing materials, controlled by electrostatic charges, are incorporated into the glazing system. These can be used to reduce glare issues and solar gain. He does admit that fuel costs will be the ultimate dictator in the choice as to whether to use large amounts of glass or more mass.
The final two panelists were from the architectural area. They were Robert Whitlock, Principal, Kohn Pedersen Fox Associates (pro-mass) and Stephan Cassell, Principal, Architectural Research Office.
Mr. Whitlock, while pro-mass, likes the idea of sun shading and light shelves, and feels the need to create a building that incorporates the biological needs of the surroundings, while bringing in daylighting.
Mr. Cassell feels that the lower floors can be all glass to create an open feel but does admit that glass use must be executed properly and there is need to incorporate some strategic use of mass, such as a spandral wall. Thus, the need to combine mass with technology.
A discussion along question and answer period followed the presenters.
The first item taken up was that of codes. Here, it was mentioned that already we have seen the outlawing of monolithic glass in Hong Kong.
Sub-metering has was also mentioned as a means of controlling energy use, as most buildings in NYC include utilities in the base rent.
Over designing, as required by certain codes, was mentioned, and it was fully agreed that this must be drastically cut back. For example many codes require the provision of as much as eight watts per square foot of space, where newer technologies in lighting and office equipment can reduce this need by more than half, in some cases to under two watts per square foot.
Another fact pointed out was that many facades do NOT meet the codes by themselves, but when combined with increased efficiencies in A/C and other building components, the overall code is met. In order for codes to be fully accepted by the public, they need to incorporate incentives to do better.
One member of the audience asked about the use of blower door tests. From the panel, it appears that they are not common place everywhere. A blower door test will confirm how much infiltration is present in the building envelope. This is important at the immediate completion of construction, and later on, as glazing settings, especially liquid silicone, can deteriorate over a period time, and leak large amounts of air around the glazing system in and out of the building.
Another audience member felt that additional power plants should NOT be built to allow for more glass use. The panelist responded by emphasizing the improvements in glazing technology.
The use of thermo gels was also asked about,but the panelists said that they are ineffective, as they tend to discolor drastically.
I asked whether it might be practical to incorporate the use of thermal storage techniques to store the heat gain taken in during the daytime in winter, and use it during the night hours. In addition, I asked if this heat could be harvested during the summer to produce domestic hot water by use of heat pump technology from the air conditioning process already in use. One could simply cool the compressor with incoming domestic water, providing free hot water for the building to use. The panelist did not feel that, at this point, that we could do this in a cost effective manner. More research is needed here.
Posted by Alan L. Englander at 5/31/2009 1:32 PM 
Categories: Market Driven Choices for Design, Codes, Building Envelope, Natural Daylighting, Energy loss, Solar Glare, Glazing, Heat Gain, Overdesigning
Categories: Market Driven Choices for Design, Codes, Building Envelope, Natural Daylighting, Energy loss, Solar Glare, Glazing, Heat Gain, Overdesigning
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