PCATP ALE flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Floor Area Ratio

Total gross floor area of all storeys divided by the plot area. Zoning bylaws cap FAR to control building bulk and population density on a site.

Setback

The minimum horizontal distance required between the property boundary and the building line. It is fixed by zoning regulation and provides light, air, and privacy.

Solar noon orientation

In the northern hemisphere the sun is due south at solar noon. South facades gain most winter sun and are easiest to shade in summer with horizontal devices.

Ramp gradient limit

A slope of 1:12 is the usual maximum for unassisted wheelchair use. Slopes of 1:20 or flatter are preferred where site space allows.

Water-cement ratio

The mass of water divided by the mass of cement in a concrete mix. Lower ratios increase strength and reduce permeability but make the fresh mix less workable.

Damp-proof course

A continuous impervious layer built into a wall near ground level to stop moisture rising by capillary action into the masonry above.

Cavity wall ties

Metal ties connecting the inner and outer leaves of a cavity wall. They transfer lateral load and must be spaced and sloped per code to shed water outward.

Lintel load triangle

The assumption that masonry above an opening loads the lintel within a 45-degree triangle rising to lintel level, rather than the full wall height.

Section modulus

A geometric property of a cross-section equal to the second moment of area divided by the distance to the extreme fibre. Bending stress equals moment divided by section modulus.

Euler buckling load

The critical axial load at which a slender column buckles, equal to pi squared times EI divided by the square of the effective length.

Simply supported beam moment

For a uniformly distributed load w over span L, the maximum bending moment is wL squared divided by eight, occurring at midspan.

Slenderness ratio

The effective length of a compression member divided by its radius of gyration. Higher values mean greater susceptibility to buckling and lower capacity.

Trap water seal

A retained depth of water in a plumbing trap, commonly 50 to 75 millimetres, that blocks sewer gas from entering the building.

Diversity factor

The ratio of maximum simultaneous demand to the sum of all connected loads. It prevents electrical supply and cable sizing from being grossly oversized.

Vent pipe function

A pipe connecting the drainage stack to outside air. It equalizes pressure so water flow does not siphon the trap seal, and terminates above roof level.

U-value

Thermal transmittance, the reciprocal of total thermal resistance. It measures heat flow in watts per square metre per kelvin; lower values indicate better insulation.

Daylight factor

Internal illuminance at a point divided by simultaneous external horizontal illuminance under an unobstructed overcast sky, expressed as a percentage.

Embodied carbon

The greenhouse gas emissions associated with extracting, manufacturing, transporting, and assembling building materials, plus their eventual disposal or reuse.

Psychrometric chart

A graph plotting dry-bulb temperature against moisture content, used to locate the comfort zone and to analyse heating, cooling, humidification, and dehumidification processes.

Practical completion

The certified stage at which the works are substantially complete and fit for purpose. It transfers possession and risk to the client and starts the defects liability period.

Professional indemnity insurance

Insurance covering the architect against claims for negligent design, errors, and omissions in professional services. It does not cover contractor workmanship defects.

Architect's instruction

The formal written mechanism by which the architect directs a variation or clarifies the works. Oral instructions should be confirmed in writing within the contract period.

Retention

A percentage withheld from each interim payment as security for performance, commonly released in two parts at practical completion and after the defects period.

Certificate of occupancy

A document issued by the building authority after inspection confirming that a completed building complies and may lawfully be occupied for its approved use.

Paramount duty to public

The architect's obligation to protect public health, safety, and welfare takes precedence over commercial loyalty to the client when the two conflict.

Street enclosure ratio

Building height divided by street width. Ratios roughly between one to one and one to three produce a comfortable, well-defined sense of urban enclosure.

Active frontage

Ground-floor building edge with doors, windows, and activity facing the street. It supports natural surveillance and street life, unlike blank walls or car parks.

Transit-oriented development

Higher-density, mixed-use development clustered within a walkable radius, commonly 400 to 800 metres, of a public transport station to reduce car dependence.

Net residential density

Dwelling units per hectare of land devoted only to housing, excluding roads, open space, and community facilities counted in gross density.

Inclusionary zoning

A planning requirement that a set percentage of units in a new residential development be provided as affordable housing, often in exchange for density bonuses.

Critical path

The longest duration sequence of dependent activities through a project network. Any delay on it delays overall completion, and its total float is zero.

Cost performance index

Earned value divided by actual cost. A value below one indicates the project is spending more than the value of work completed to date.

Liquidated damages

A pre-agreed sum payable by the contractor for delay, representing a genuine estimate of the client's loss. It must not be a punitive penalty.