CID cheat sheet

Net assignable area is the usable floor area of a space, excluding walls, columns, and circulation; gross area includes all enclosed and unenclosed spaces within the building envelope.

Efficiency ratio = net assignable area ÷ gross area; typical office target is 0.75–0.85, while educational and healthcare facilities often run lower due to circulation and service space.

Programming phases: goals and objectives, fact-finding, concept development, needs assessment, and synthesis; the program document states area requirements, adjacencies, and performance criteria before design begins.

Adjacency matrix: rows and columns list spaces; each cell rates required proximity (e.g., 0 = no relationship, 1 = adjacent, 2 = near, 3 = distant) to guide block planning.

Bubble diagram shows functional relationships without scale; block plan adds approximate area and shape; both precede schematic design.

Circulation allowance is typically 20–30% of net area in offices and 30–40% in healthcare or assembly occupancies; confirm with the client's program.

Universal design principles: equitable use, flexibility, simple and intuitive use, perceptible information, tolerance for error, low physical effort, and appropriate size and space.

Occupant load for egress is calculated from Table 1004.5 of the International Building Code (IBC); for example, business use is 150 gross square feet per occupant, assembly unconcentrated is 15 net square feet per occupant.

IBC occupancy groups: A (assembly), B (business), E (educational), F (factory), H (high hazard), I (institutional), M (mercantile), R (residential), S (storage), U (utility); mixed occupancies require separation or compliance with the most restrictive provisions.

Type I construction is the most fire-resistive (noncombustible, high hourly ratings); Type V is the least (wood frame). Height and area limits increase as construction type becomes more resistive.

Means of egress components: exit access, exit, and exit discharge; travel distance limits vary by occupancy, typically 200–300 feet for sprinklered business occupancies.

Accessible routes must be at least 36 inches clear width; a 60-inch turning space is required at dead ends and within toilet rooms; door clear width is 32 inches minimum.

ADA Standards for Accessible Design: ramps maximum slope 1:12 (8.33%), maximum rise 30 inches per run, landings at top and bottom, handrails on both sides if rise exceeds 6 inches.

Fire-resistance-rated assemblies: a 1-hour wall typically requires 5/8-inch Type X gypsum board on each side of studs; penetration and joint firestopping must maintain the rating.

Zoning ordinances regulate use, height, bulk, setback, floor area ratio (FAR), and parking; FAR = total building floor area ÷ lot area.

Life safety: occupant load determines number of exits (two required when load exceeds 49 for most occupancies), exit width (0.2 inches per occupant for level components), and signage requirements.

CSI MasterFormat organizes specifications into 50 divisions; Division 01 covers general requirements, Division 03 concrete, Division 05 metals, Division 08 openings, Division 09 finishes.

Specification types: proprietary (names a single product), performance (states required results), and prescriptive (describes materials and methods); basis-of-design specifications allow substitutions with approval.

Concrete: compressive strength typically 3,000–5,000 psi; water-cement ratio controls strength and durability; curing maintains moisture and temperature for hydration.

Steel: ASTM A992 is common for wide-flange shapes; yield strength 50 ksi; connections are bolted or welded; fireproofing (spray-applied or intumescent) is required for ratings.

Wood: nominal dimensions differ from actual (2x4 is 1-1/2 x 3-1/2 inches); moisture content affects shrinkage; pressure-treated lumber for exterior and ground contact.

Masonry: mortar joint types (N, S, M, O) vary in strength; typical brick veneer uses 1-inch air space and wall ties; flashing and weep holes manage moisture.

Building envelope: vapor retarders on the warm side of insulation in cold climates; air barriers continuous; rainscreen design separates cladding from drainage plane.

Submittals include shop drawings, product data, samples, and mockups; the architect reviews for design intent but does not approve means and methods, which remain the contractor's responsibility.

Illuminance is measured in footcandles (fc) or lux; 1 fc = 10.76 lux; typical office lighting is 30–50 fc, while corridors may be 10 fc.

Luminous efficacy (lumens per watt) compares lamp efficiency; LED sources typically exceed 100 lm/W, fluorescent about 80–100 lm/W, incandescent about 15 lm/W.

Color rendering index (CRI) ranges 0–100; values above 80 are generally acceptable for interiors; correlated color temperature (CCT) in kelvin describes warmth (2700K) to coolness (5000K).

Electrical load calculations: total connected load (watts) ÷ voltage = amperes; demand factors reduce load for diversity; panel schedules balance phases.

HVAC: sensible heat ratio = sensible load ÷ total load; latent load comes from moisture; ventilation rates per ASHRAE 62.1 based on occupancy and floor area.

Duct sizing: equal friction method uses a constant pressure drop per unit length; velocity method uses maximum velocity limits; both balance noise and energy.

Plumbing: fixture units (FU) determine pipe sizing; water supply pressure must be adequate at the highest fixture; drainage slopes typically 1/4 inch per foot for 2-inch and smaller pipe.

Fire protection: sprinkler systems require a water supply with adequate pressure and flow; standpipes for buildings over a certain height; smoke detectors and notification appliances per NFPA 72.

Drawing scales: architectural (1/4 inch = 1 foot) for plans, engineering (1 inch = 20 feet) for site plans; metric scales use ratios such as 1:100.

Line types: object lines (thick), hidden lines (dashed), center lines (long-short), dimension lines (thin), cutting plane lines (heavy with arrows).

Orthographic projection: plan, elevation, and section views; plans are cut horizontally at about 4 feet above floor; sections show vertical relationships.

Construction documents consist of drawings and specifications; drawings show location and dimensions; specifications describe materials, standards, and workmanship.

BIM (Building Information Modeling) supports coordination, clash detection, and quantity takeoffs; Level of Development (LOD) 100–500 defines model detail.

Dimensioning conventions: string dimensions along a line, overall dimensions, and location dimensions; avoid duplicating dimensions in both plans and details.

Schedule types: door, window, finish, and equipment schedules tabulate properties and quantities; they are part of the contract documents.

Revision control: clouding changes on drawings, issuing addenda during bidding, and change orders during construction; each revision has a number and date.

Standard AIA agreements: B101 (owner-architect), A101 (owner-contractor), A201 (general conditions); these define roles, responsibilities, and risk allocation.

Basic services typically include schematic design, design development, construction documents, bidding/negotiation, and construction contract administration; additional services are billed separately.

Fee structures: percentage of construction cost, lump sum, hourly, or cost plus fixed fee; percentage fees decrease as project cost increases.

Project delivery methods: design-bid-build (linear), design-build (single entity), and construction manager at risk (CMAR) with guaranteed maximum price.

Professional liability: architects are responsible for standard of care, not perfection; errors and omissions insurance covers negligence; statutes of limitation and repose limit claim periods.

Bidding: additive and deductive alternates, unit prices, and allowances; bid opening and evaluation; award to lowest responsible bidder.

Construction administration: submittals, RFIs, change orders, payment applications, and substantial completion; the architect certifies payment but does not guarantee the contractor's work.

Ethics: avoid conflicts of interest, maintain confidentiality, compete fairly, and report violations; NCARB and AIA codes of ethics guide professional conduct.