Moving to mainstream solutions
There are powerful market forces that are pushing some owners and design teams to architectural solutions utilizing highly glazed, transparent façades. We have followed these trends and note that there are clear potential benefits to such approaches but at the same time real risks and costs associated with them as well. The interest in potential benefits from these design solutions can be summarized with the following generalized statements:
- More building owners desire daylight. Many find the architectural concepts and buildings that employ highly transparent façades a refreshing turnabout from the opaque, dark tinted or reflective buildings of the 1970s and 1980s.
- More building owners are aware of the potential health and productivity benefits of daylight. Even without rigorous proof of these benefits the interest remains.
- With the increased use of low-reflectance, higher brightness flat-screen LCD monitors, architects can now turn away from the practice of hiding people in dark rooms so that they can view their older CRT screens and can now use design solutions that involve increasing the daylight and luminance levels within buildings.
- The shift toward highly glazed façades can be coupled with interior designs that complement the desire of building owners to provide view and daylight to more employees. With open-plan, low-height partition furniture layouts, the daylit zone can be extended from a conventional 3.0-4.6 m (10-15 ft) depth to a 6.1 m (20 ft) or even 9.1 m (30 ft) depth from the window wall.
At the same time the potential risks associated with highly glazed façades are understood by many design teams and owners as well. These include:
- Inadequate tools to reliably predict thermal and optical performance of components and systems, and to assess environmental quality.
- Increased cooling loads and cooling energy use for the larger, highly transparent glazings, with the potential for thermal discomfort.
- Increased visual discomfort from sun penetration and from brightness levels that exceed good practice for those using computer systems in daylighted offices.
- High cost of purchasing lighting controls utilizing dimming ballasts and difficulty in commissioning the system after installation.
- High cost of automated shading systems and difficulty in commissioning the system after installation.
- Cost and technical difficulty of reliably integrating dimmable lighting and shading controls with each other and with building automation systems to ensure effective operation over time.
- Uncertainty in occupant behavior with use of automated, distributed controls in open landscaped office space and potential for clash between different needs and preferences.
To capture the potential benefits and minimize the risks there is a growing recognition that at least in work spaces (as distinct from circulation, lobbies, etc.), large glazed spaces require much better sun control and glare control, and that these solutions must be delivered by dynamic systems whose properties change in response to exterior climate and interior needs. A major challenge for manufacturers is thus how to provide the needed increased functionality at lower cost and risk to owners. Using detailed experience from the mockup, LBNL and the Times Company team have evolved a model for how the markets for integrated daylighting controls and automated shading systems might be transformed to provide improved functionality at lower cost. Dimming ballasts and automated shading systems are key technologies whose cost and performance are critical to the building solution, however, there are several fundamental limitations: 1) they are too costly and 2) they can not be readily and cheaply commissioned after construction.
Various strategies were used to address bottom-line cost, one of which was discussed in The Owner's Approach which focused on shifting the market from the current "low volume, high cost" paradigm to a "high volume, low cost" approach. The Times Company team actively collaborated with owners and design teams from other major projects in the New York area by inviting them to visit the mockup and join the effort to promote the vision of low cost dimmable lighting and dynamic shading.
Another unique strategy employed by the Times Company was to study the various costs associated with the assembly and installation of these systems, then devise procurement and engineering solutions to obtain competitive costs for these innovative systems. For example, the end-to-end recessed lighting was engineered so that the fixture housing became the raceway for both power and the control network. Photoelectric and occupancy sensors were installed in series to the same digital network. The fixtures were purchased directly by the Times Company then shipped from the factory pre-wired with the ballasts, lamps, and a dust cover, which was removed only after the furniture was installed. To obtain competitive installation bids, The Times Company required that all bidders attend an informational workshop at the daylighting mockup where all aspects of installation were explained and illustrated with detailed boards provided by the manufacturers. The Times Company obtained significant reductions in cost using these combined strategies and was able to achieve a cost-benefit payback of less than 5 years.
For a more detailed description of these cost-saving strategies, a transcription of a talk given by Glenn Hughes, Managing Director of The New York Times Company, at LightFair 2007 has been provided.
Also, see Harvard Business Review article by David Thurm, CIO of The New York Times Company, in the Publications section.