“Commodity, firmness and delight” are the three indispensable qualities of good architecture, according to Roman architect Vitruvius of the 1st century B.C. Firmness is withstanding nature’s forces, delight is achieving beauty and commodity is ensuring building functionality. Regrettably, when architects design buildings, the pursuit of delight sometimes trumps commodity. And if not trumped by delight, commodity might be compromised by budget constraints or simply design incompetence.

Contemplate your home, workplace, school or any other building you visit and use, and you undoubtedly can identify architectural-design deficiencies, as opposed to technical or building-material defects, ranging from annoyingly inconvenient to uncomfortable to seriously dysfunctional. Sometimes deficiencies are substantial enough to impede effective building use.

Compromised functionality can include spaces and passageways undersized for their purpose and occupancy; overly circuitous or illegible interior circulation patterns that make navigation difficult; and awkwardly shaped rooms impossible to furnish or use efficiently, perhaps exacerbated by poorly placed windows and doors. Public restrooms are often too small, elevators too few, stairways too narrow. Such deficiencies can exist in buildings of all types and sizes — homes, hotels, hospitals, schools, offices, commercial buildings, museums, houses of worship and parking garages.

In many homes and apartments, excessively tight kitchens restrict movement and provide inadequate counter and storage space. Improperly deployed kitchen appliances can hinder food preparation. Cabinet- and oven-door swings might interfere with opening kitchen drawers. Even an open refrigerator door can be an irritating obstacle.

In residential bathrooms, improper placement of sinks, toilets, bathtubs and shower stalls in relation to one another and to the bathroom door can necessitate convoluted movement. Too few or inconveniently located towel racks are a common problem. And how many millions of homeowners have complained about inadequate closet space?

Clients hire architects to design buildings to serve specific purposes and function in specific ways. The functional “program,” either provided by the client or generated by the architect, is typically an elaborate menu of spaces stipulating use, occupancy, floor area and room-adjacency requirements. For each space, the menu describes characteristics and content required for each function: furnishings and equipment; mechanical and electrical needs; lighting and acoustical requirements; and other special features.

Consulting engineers, contractors and subcontractors generally assume most of the responsibility for correctly designing and constructing a building’s technical systems — the structure, heating, ventilation and air-conditioning systems, and electrical and plumbing configurations. But the architect is responsible for a building’s overall form and geometry, for the three-dimensional spatial composition and functional arrangement of its interior. The architect determines where to deploy entries and lobbies, corridors, individual rooms, stairs and elevators. Location and design of doors, windows and skylights, along with guardrails and other visible details, are likewise the architect’s responsibility.

A client’s program, if well conceived, is in effect a written model that clearly expresses the client’s functional agenda. It guides many of the architect’s pragmatic design decisions but also can inspire and catalyze design decisions that produce architectural delight.

Yet satisfying the client’s programmatic agenda can conflict with the architect’s aesthetic agenda, which is where things can go wrong. In the extreme, for example, imagine an architect proposing a circular, daylight-filled room enveloped by glass walls, but a client intending to hang paintings in the room. Unless the client changes the program, the architect’s concept for the room won’t work. Thus the client and architect will have to negotiate, and most likely the architect will develop a new concept.

In fact, continual design negotiations between architect and client are integral to the design process. For the process to be constructive, the architect must respect and seek to meet the client’s objectives, and the client likewise must respect and support the architect’s creative aspirations.

Talented architects who are creative and responsible take pleasure in reconciling contrasting agendas. The client’s functional program is seen not as an impediment to artful design, but as a source of design inspiration, along with the project site and context, local culture and history, available technology and the architect’s own aesthetic philosophy. For such architects, the design goal is commodity and delight, not commodity or delight.

Roger K. Lewis is a practicing architect and a professor emeritus of architecture at the University of Maryland.