APPENDIX B
GLOSSARY OF TERMS
The following definitions have, in some cases, been developed to address the particular considerations of building or facility obsolescence, as discussed by the committee. Readers may wish to refer to the several texts and articles cited throughout this report for additional information on or detailed discussion of these terms.
A
ACCESSIBLE SERVICE AREAS.
Space designed into a facility specifically to facilitate maintenance, repair, and modification of one or more building subsystems. Interstitial space (e.g., in ceilings), raised access floors, and electrical and mechanical canyons are examples of accessible service areas.
ADAPTIVE REUSE.
Conversion of a facility or part of a facility to a use significantly different from that for which it was originally designed.
B
BUILDING.
Type of constructed facility.
BUILDING PORTFOLIO.
A collection of buildings or other constructed facilities managed by a single agency or other owner.
C
CANYON.
Vertical service bays designed to house communications, electrical, and mechanical service distribution equipment in a readily accessible way; a type of accessible service area.
COMMISSIONING.
An activity, commenced at completion of construction and often including initial user occupancy, intended to check functional subsystems, to determine that the facility is functioning properly, and to undertake any necessary remedial action. Commissioning typically spans a period of 6 to 12 months.
COMPONENT.
A part or product specified for use in a constructed facility (e.g., air chiller units, floor joists, and ceiling panels). Also referred to as an element.
CONSTRUCTED FACILITY.
The physical product of construction activities, comprising an assemblage of relatively distinct functional systems, subsystems, elements, and components.
CONSTRUCTION CRITERIA BASE (CCB).
A commercially available compendium of agency design criteria stored on computer-accessible compact disk.
COSTS OF OWNERSHIP.
The total of all costs incurred, generally by the owners but also by the users, to obtain the benefits of a facility.
D
DESIGN SERVICE LIFE.
The period of time over which a building or a building subsystem or component (e.g., the roof, mechanical equipment, plumbing, or sheathing) is designed to provide at least an acceptable minimum level of shelter or service, as defined by the owner; typically depends on assumptions, sometimes implicit, regarding satisfactory completion of normal maintenance activities. An idealized service life.
E
ECONOMIC LIFE.
The period of time over which costs are incurred and benefits or disbenefits are delivered to an owner; an assumed value sometimes established by tax regulations or other legal requirements or accounting standards and not necessarily related to the likely service life of a facility or subsystem.
ELEMENT.
See component.
H
HVAC.
Heating, ventilation, and air conditioning.
I
INTEGRATED BUILDING SYSTEMS.
Functional systems designed specifically to fit and work together as a larger system; intended to provide better performance than systems not designed for integration.
INTERSTITIAL SPACE.
A type of accessible service area, typically space provided between the structural floor panel and a hung interior ceiling; a key element of VAHBS (VA Hospital Building System), a 9-foot floor-between-floors that houses mechanical and electrical components.
L
LIFE CYCLE.
The sequence of events in planning, design, construction, use, and disposal (e.g., through sale, demolition, or substantial renovation) during the service life of a facility; may include changes in use and reconstruction.
LIFE-CYCLE COST.
The present value of all anticipated costs to be incurred during a facility's economic life; the sum total of direct, indirect, recurring, nonrecurring, and other related costs incurred or estimated to be incurred in the design, development, production, operation, maintenance, support, and final disposition of a major system over its anticipated useful life span.
M
MODULARITY.
The separation of major user areas into zones served by independent mechanical and electrical components; also a characteristic of
integrated building systems, in which repetitive use of components and subsystems facilitates facility maintenance and repair.
O
OBSOLESCENCE.
The condition of being antiquated, old fashioned, or out of date, resulting when there is a change in the requirements or expectations regarding the shelter, comfort, profitability, or other dimension of performance that a building or building subsystem is expected to provide. Obsolescence may occur because of functional, economic, technical, or social and cultural change.
OPENING CONFIGURATION.
The specifics of use dictated by the building owner and initial users during the earliest stages of project development; the spatial and systems configuration that should be considered as simply the first of many uses for which the building should be planned.
P
PERFORMANCE.
The degree to which a building or other facility serves its users and fulfills the purpose for which it was built or acquired; the ability of a facility to provide the shelter and service for which it is intended.
PERIODIC RENEWALS.
Regular changes of items, such as replacing carpets, painting, or overhauling compressors.
PHYSICAL LIFE.
The time it takes for a building, subsystem, or component to wear out or fail the ''time period after which a facility can no longer perform its function because increasing physical deterioration has rendered it useless.''
PLANNED SHORT SERVICE LIFE.
A decision that the service life of a facility should be shorter than might typically be expected; implies selection of components that have low first cost and low durability; similar to the term "planned obsolescence" used in the automobile and consumer products industries.
POSTOCCUPANCY EVALUATION.
Collection and analysis of information, particularly from users, to assess how well a facility's performance matches user needs and design intent.
PREDESIGN ANALYSIS.
The system of analysis involved in developing conceptual design alternatives and working out a variety of design details before the actual detailed design begins.
PRESENT VALUE.
A concept in economics reflecting the time-value of money, in which costs and revenues of future years are expressed in terms of the amounts they would be equivalent to if they occurred in the present year; sometimes termed "discounted value."
PROGRAMMING.
Activities that lead to determination of the specific scale, scope, and timing of facility construction; typically precedes consideration of spatial configurations, but when used in the architectural sense, includes determination of required floor areas and adjacencies of various uses of the facility.
R
RAISED ACCESS FLOOR.
Platform built several inches above the structural floor, creating a space to house communication, electrical, and mechanical distribution equipment; a type of accessible service area.
RENEWAL.
Substantial repairs and improvements in a facility or subsystem that returns its performance to levels approaching or exceeding those of a newly constructed facility.
RETROFIT.
The redesign and reconstruction of an existing facility or subsystem to incorporate new technology, to meet new requirements, or to otherwise provide performance not foreseen in the original design.
S
SERVICE LIFE.
The period of time over which a building, component, or subsystem actually provides adequate performance; a technical parameter that depends on design, construction quality, operations and maintenance practices, use, environmental factors, and users' and owners' expectations; not the same as economic life or design service life.
SHELL SPACE.
Space in a facility for which the structural system and typically the exterior envelope are complete but in which other functional subsystems are left for completion at some future time.
SUBSYSTEM.
Functional part of a system, and often used interchangeably with that term (e.g., heating subsystem [part of HVAC system]).
SYSTEM.
Collection of subsystems, components, or elements that work together to provide some major aspect of shelter or service in a constructed facility (e.g., plumbing system, electrical system, and roofing system). Also, a set of building components specifically designed to work together to facilitate construction (e.g., integrated building system).