PCATP ALE cheat sheet

Site analysis precedes design: record solar orientation, prevailing wind, topography, drainage, vegetation, noise sources, and access before fixing building form.

Solar geometry rule: in the northern hemisphere the sun is due south at solar noon; a south-facing facade receives maximum insolation at winter solstice and is easiest to shade at summer solstice.

Setback is the minimum horizontal distance from the property line to the building line; it is fixed by zoning bylaw, not by the architect.

Floor Area Ratio (FAR) = total gross floor area ÷ plot area; Coverage = footprint area ÷ plot area; both are capped by zoning.

Building height is measured per local bylaw - commonly to the mean roof level or to the top of the parapet, not to the highest point of a pitched roof.

Universal access: a 1:12 ramp slope is the usual maximum for unassisted wheelchair use; 1:20 or flatter is preferred where space permits.

Means-of-egress travel distance and dead-end corridor limits are set by the local building code; verify the governing edition before layout.

Cross-ventilation requires inlet and outlet openings on opposite or adjacent walls; single-sided ventilation is markedly less effective.

Concrete cover to reinforcement is specified by exposure class; cover protects against carbonation and chloride ingress, so it is a durability requirement, not a finish allowance.

Concrete cube strength is tested at 7 and 28 days; 28-day characteristic strength is the design value used in structural calculations.

Water-cement ratio governs both strength and permeability: lower w/c gives higher strength and lower permeability, offset by reduced workability.

Brick masonry in English bond alternates header and stretcher courses; Flemish bond alternates header and stretcher within each course.

Cavity walls require wall ties at spacing set by code and weep holes at the base of the outer leaf to drain moisture.

Damp-proof course (DPC) blocks rising moisture in walls; damp-proof membrane (DPM) performs the same role under a ground slab.

A lintel spans an opening and carries the load above it; the usual allowance is a 45-degree load triangle up to the lintel level.

Formwork striking times depend on member type and curing temperature; slabs and beams are struck later than vertical faces.

Bending moment for a simply supported beam under uniformly distributed load w over span L: M = wL²/8; maximum deflection for the same case: δ = 5wL⁴/(384EI).

Section modulus S = I/c; bending stress σ = M/S. Increasing depth raises I and S far faster than increasing width.

Slenderness ratio λ = effective length ÷ radius of gyration; buckling capacity falls as λ rises.

Euler buckling load P_cr = π²EI/(KL)², where K depends on end restraint (0.5 fixed-fixed, 0.7 fixed-pinned, 1.0 pinned-pinned, 2.0 cantilever).

Steel is strong in tension and compression but needs restraint against lateral-torsional buckling; concrete is strong in compression and weak in tension, hence reinforcement.

Thermal expansion must be accommodated with movement joints; the coefficient of thermal expansion of steel is roughly 12 × 10⁻⁶ per °C.

Timber strength depends on grain direction: parallel-to-grain strength is far higher than perpendicular; design values are modified for duration of load and moisture content.

Poisson's ratio relates lateral to axial strain; for concrete and steel it is approximately 0.2 and 0.3 respectively.

Water supply pressure in a building falls with height and friction; a break tank and booster pump set are used where mains pressure is insufficient for the topmost outlets.

Plumbing traps retain a water seal (commonly 50-75 mm) to block sewer gas; the seal is lost by siphonage, evaporation, or back-pressure.

A vent pipe equalizes pressure in the drainage stack and prevents trap seal loss; it must terminate above roof level.

Electrical: total connected load is summed with diversity applied to derive maximum demand; protective device rating must not exceed cable current-carrying capacity.

Earthing and residual-current protection are separate safeguards: earthing provides a fault path, RCD detects imbalance and disconnects.

Lift traffic design uses handling capacity and interval; a common design target is to move a set percentage of the building population in five minutes.

Fire detection zones should broadly follow floor plates so that a fire alarm indicates a searchable area, not an entire tower.

HVAC duct sizing by equal friction method keeps static pressure loss per unit length constant along the main run.

Thermal transmittance U is the reciprocal of total thermal resistance: U = 1/R_total; lower U means better insulation.

Psychrometric chart: dry-bulb temperature on the horizontal axis, moisture content on the vertical; comfort zone lies between them, bounded by humidity limits.

Effective temperature combines dry-bulb, humidity, and air movement into a single comfort index.

Passive design priority: reduce load first (orientation, shading, insulation), then size systems - never size plant before load reduction.

Daylight factor = internal illuminance ÷ simultaneous external horizontal illuminance under overcast sky, expressed as a percentage.

Embodied carbon is the emissions associated with materials and construction; operational carbon is emissions during use. Whole-life carbon sums both.

Rainwater harvesting sizing depends on catchment area, rainfall depth, and demand; storage volume is set by the dry-period demand, not annual rainfall.

Green roof benefits include stormwater attenuation, reduced heat island effect, and additional insulation, but require structural load allowance for saturated soil.

The architect's standard scope covers design, production information, and periodic site inspection; full-time supervision is a separate service and must be agreed in writing.

Fees are commonly computed as a percentage of construction cost, as a lump sum, or on a time basis; the basis and stage payments belong in the appointment agreement.

Professional indemnity insurance covers negligent acts, errors, and omissions in the professional service; it does not cover construction defects caused by the contractor.

Architect's instruction is the formal mechanism to vary the works; oral instructions should be confirmed in writing within the contract's stated period.

A certificate of practical completion transfers risk and possession to the client and starts the defects liability period.

Retention is a percentage withheld from each payment, commonly released in two parts: at practical completion and at the end of the defects period.

Copyright in the drawings generally remains with the architect; the client receives a licence for the purposes stated in the appointment.

Conflict of interest must be declared and managed in writing; acting for both client and contractor on the same project is normally prohibited.

Registration to practise is personal and non-transferable; practising without current registration is an offence under the governing architects' act.

The architect's paramount duty is to the public's health, safety, and welfare, which outranks commercial loyalty to the client.

Building permit submission typically requires drawings, structural calculations, and a site plan demonstrating compliance with zoning and building code.

A certificate of occupancy or completion is issued by the authority after inspection; occupation before it is unlawful.

Fire safety design rests on three pillars: means of escape, fire resistance of structure, and control of fire spread - plus access for firefighting.

Confidential client information may not be disclosed without consent except where required by law or where safety is at risk.

Signing or certifying work that the architect has not personally directed or reviewed is a disciplinary offence.

Professional conduct rules generally prohibit misleading advertising, fee undercutting by unsafe scope reduction, and undisclosed commissions from suppliers.

Urban design operates at the scale between architecture and town planning: block form, street enclosure, public realm, and frontage.

Enclosure ratio = building height ÷ street width; ratios around 1:1 to 1:3 produce a comfortable sense of street enclosure.

Active frontages place doors, windows, and shopfronts at ground level; blank walls and car parks at grade kill street life.

Permeability is measured by the number of route choices; connectivity and cul-de-sac layouts trade off against each other.

Transit-oriented development clusters higher density within a walkable radius (commonly 400-800 m) of a station.

Legibility, after Kevin Lynch, rests on paths, edges, districts, nodes, and landmarks as the mental image of a city.

Eyes on the street (Jane Jacobs) links natural surveillance to safety: overlooking windows and foot traffic deter crime.

Universal design in public space covers level changes, tactile paving, seating intervals, and shade along pedestrian routes.

Zoning separates land uses and sets permitted use, density, height, setback, and parking requirements for each zone.

Density is expressed as dwelling units per hectare or as plot ratio; both must be checked against the zoning bylaw, not estimated.

Land subdivision requires a layout plan showing roads, plots, open space, and services; approval precedes sale of plots.

Housing typology ranges from detached and semi-detached through terraced and walk-up flats to high-rise apartments; each has different net-to-gross efficiency.

Net residential density counts only residential land; gross density includes roads, open space, and community facilities.

Affordable housing obligations are commonly met through inclusionary zoning: a set percentage of units in a development.

Master plans are strategic and indicative; zoning or development control regulations are the legally binding instrument.

Public participation in plan-making is usually a statutory requirement, with objections heard at an inquiry or hearing stage.

Critical path method: the critical path is the longest duration path through the network; any delay on it delays completion.

Total float = latest finish − earliest finish; float is zero on the critical path and positive elsewhere.

Gantt charts show time but not logical dependency; network diagrams show dependency and are used for float analysis.

Earned value: CV = EV − AC (cost variance), SV = EV − PV (schedule variance), CPI = EV/AC, SPI = EV/PV.

A work breakdown structure decomposes scope into manageable packages; each package should be assignable to one responsible party.

Fast-tracking overlaps design and construction to compress time; crashing adds resources to critical activities at extra cost.

Design coordination clashes are resolved through a common data environment and federated models before construction information is issued.

Risk register records likelihood, impact, owner, and mitigation; risk allocation should follow the party best able to control it.

Lump-sum contract fixes price for defined scope; any change is a variation. Re-measurement contracts pay for actual quantities at agreed rates.

Bills of quantities are prepared from drawings and measured to a standard method of measurement; they form the basis for tendering.

Approximate quantities estimate uses rates per unit of floor area or per bed space and is used only at feasibility stage.

Cost plan stages follow design stages: order-of-cost, elemental, and detailed - accuracy improves as design information grows.

Variation valuation order: contract rate applies if work is similar; a fair rate is derived if not; dayworks apply for small unforeseen work.

Liquidated and ascertained damages are a pre-estimate of the client's loss for delay, not a penalty; they must be genuine.

Interim payments are certified at intervals; the certificate is the architect's independent valuation, not the contractor's claim.

Final account reconciles the contract sum with all variations, provisional sums, and adjustments after the defects period.