One year ago construction began in the sixth wing proper of the Main Interior Building. Still in the first of six phases, the nuances associated with a major renovation "modernization" of existing space in an occupied building are being learned. The Project, being administered by GSA's Public Building Service/National Capital Region, will take 9 years and the second phase is not scheduled to begin until May 2004. Obviously, many factors shaped the scope of the modernization efforts, however, the majority of these factors fall within one or more of the following seven, design parameters; life safety, environmental safety, security, historic preservation, sustainability, accessibility and technology.

In the last issue of the NBC Profile we focused on life safety enhancements being implemented. Since the publication of that issue we are happy to report that the new 600 KVA emergency generator has pasted it's initial round of load tests and is nearing operational status. In addition to the fire pump and other life safety systems, as each wing is modernized, emergency lighting, circuits, and elevator banks will be afforded back up power capabilities. In this issue we will touch on how the quality of our indoor work environment will be affected.

The first major improvement to our indoor air quality is the removal of the existing evaporative spray washers, ductwork and associated induction units. As you may or may not be aware, these components made up the first central air conditioning system installed in a large Federal office building. The system works by moving large volumes of air at a relatively low velocity through a fine mist spray chamber. The water is first cooled by chillers located in the central plant. As this water is released in the form of a fine mist, warm air is cooled as it passed through the mist and is distributed by one of the 36 different air handlers located in the basement and mechanical level. The mechanical level is an entire floor located between the 5th and 6th floors dedicated solely to building systems used in operating this 1.3 million square foot facility. When heating is required, steam produced by GSA is brought to the building and distributed by forced air through a network of steam coils in air handlers, and by induction in the individual offices. This system, is being replaced by a 4-pipe fan coil system. While the induction units are being removed from the offices, the new fan coil units are being retrofit within the existing metal casework, so aesthetically, the typical office will look identical to the original construction. The occupant will notice several slight changes. The first being the lack of black soot that usually greets the occupant when they first enter their office in the morning. Secondly, the occupant will have the ability to control the temperature and fan speed of their individual units. For many years the Division of Facilities Management Services has diligently wrestled with and performed protocols and maintenance to insure the healthful condition of an ageing system. Not only will many of the headaches associated with operating a 68 year old system be reduced the energy efficiency of the system will be increased. Combined with the new R-10 rigid insulation board being applied to the interior brick construction of the exterior walls, the temperature control of the space will be much improved.

A discussion of how the interior environment will be impacted, involves much more than just the climatic concerns of heating, cooling, humidification and the amount of outside air introduced. Obviously, the construction process introduces thousands of new chemicals and materials into a space that for energy performance reasons we want to make relatively airtight. Additionally, to build, one must destroy. The process itself generates a considerable amount of dust and particulates into the space. Many of the materials that were considered cutting edge performers in the acoustic, insulating and fire safety realm contain asbestos, heavy metals other hazardous materials and must be identified and handled in very specific ways so as not to contaminate the space or pose a danger to the occupants or the workers. To address these concerns, GSA has retained an independent, on-site, environmental monitoring contractor, to insure all work is performed within the District and Federal regulations. This includes air monitoring and final clearance for all asbestos and lead abatement activities. Engineering controls are in place to assure the contractor is aware of the requirements, follows establish procedures, and the proper testing and clearance of the work area occurs before the containment barriers are removed and general construction activities can commence. Additionally Random air sampling is being conducted in the public spaces to insure the safety of the occupants. To address new materials being employed on the project, submittals are required such as, an MSDS (Material Safety Data Sheet) identifying chemicals and precautions associated with the use of the individual product. An IAQ plan (Indoor Air Quality) outlines the procedures the contractor must follow to minimize the amount of dust and particulates produced by the various construction processes. The DOI has been successful in influencing the use of products such as peel and stick carpet tiles, and low VOC (Volatile Organic Compounds) paints. Currently, the project is attempting to use the LEED EB (Leadership in Energy and Environmental Design for Existing Buildings) rating system as a benchmarking tool to measure the level of achievement in many of these areas and in the next article will touch a little more on what environmental considerations have been incorporated into the design and what sustainable practices are currently being implemented.

For more information

Dirk Meyer

Dirk_J_Meyer@nbc.gov