Value Beyond Cost Savings - Green Building Finance Consortium

Value Beyond Cost Savings: How to Underwrite Sustainable PropertiesWhen applying such general studies to a particular property, it is important to carefullyassess the applicability of the research (time of study, property type, comparability ofsustainable features/outcomes, geography, etc.), its quality, and key underlyingassumptions. In general, particular care must be observed when combining cost and benefitcalculations from separate feature analysis due to double-counting and related issues.Substantial additional information on sustainable features is presented in Expanded ChapterIII, Section C: “Sustainable Property Features” and in Appendix III-A of Expanded ChapterIII: “Sustainable Property Features Menu” as well as in the Research Library under indexcodes 6.0, 12.0, 15.5 and 28.0.a. Underfloor Air DistributionUnderfloor air distribution (UFAD) is an approach to ventilation in commercial andinstitutional buildings in which conditioned air is distributed through a plenum or cavitycreated by raised floors, which also typically carry electrical and communications cabling.One common cause of problems related to UFAD is plenum leakage, either through theplenum into other building cavities or from the plenum into the occupied space via thefloor. This leakage can result in many problems, including loss of thermal comfort, wastedenergy, ventilation noise, and condensation in the plenum. Such condensation canultimately lead to growth of biological material or mold, which can seriously impair airquality and may result in liability for the building owner.Other risks include specifying the proper thermal mass of the slab and plenum, properdesign of forced air systems to match floor plates, proper insulation of ducting, and propercoordination of internal tenant improvements and vents.According to the UC Berkeley Center for the Built Environment, a key researcher of UFADsystems, the key factors to the success of UFAD design are:1. The experience of the project team2. Appropriate location and climate3. Proper integrated design process4. HVAC control strategies5. Sufficient training of building management staff.Vendor input is essential during the design and construction phase for a successful underfloor air distribution system.It should also be acknowledged that UFAD systems are a more difficult challenge forexisting buildings, typically much more costly than in new construction, and in many cases51