Building Science and Systems

How buildings actually work. Foundations, structural concepts, envelope performance, ventilation, and durability under climate.

References

The books behind these questions.

Every Building Science and Systems practice question links back to the reference you'd use in the real exam.

What you'll be tested on

The skills behind Building Science and Systems questions.

Examitect drills each of these areas. The list below maps to the question categories you'll see inside.

  • Understand soil behaviour, foundation systems, and ground conditions
  • Apply structural concepts: load paths, member sizing, deflection, lateral systems
  • Understand envelope performance: heat, air, moisture, and water management
  • Evaluate roof systems and rainwater management strategies
  • Apply ventilation principles for indoor air quality
  • Coordinate building systems with climate and durability expectations

Why this topic matters. Building science questions test whether you understand the physics of a building. Examiners reward candidates who can predict assembly behaviour from first principles, not just memorize prescriptive numbers.

Study Notes on Building Science and Systems

Building science basics

Buildings work by managing energy (heat, electricity, light), matter (water, air, vapour), and load (gravity, lateral). Building science is the study of those flows and how design choices affect them. Get the physics right and the prescriptive code numbers are easier to remember.

What this topic covers

Six clusters: soil and foundations (bearing, settlement, frost, drainage), structural concepts (loads, paths, lateral systems), envelope (the four control layers, again), roofing (low-slope vs steep, drainage, ice damming), ventilation (natural, mechanical, mixed mode), and durability (corrosion, decay, weathering).

Numbers worth memorizing

Frost depth in Canada: typically 1200 to 1800 mm. Soil bearing: 100 to 200 kPa for normal soils. Floor live loads: 1.9 kPa residential, 2.4 kPa office, 4.8 kPa assembly. Roof slopes: low-slope is less than 1:12 (or 2:12 by some references), steep is 1:12 or more. Wood framing typically at 16 inches o.c.; light steel commonly at 24 inches o.c.

Common ExAC traps

Watch for distractors that fix a building problem with an unrelated system. Condensation problems are envelope problems first (control layers, dew point); HVAC fixes are secondary. Don't add insulation to fix water intrusion; fix the water management first.

Placeholder notes. Full Building Science and Systems notes (with diagrams, worked examples, and references) ship with paid access.

Estimated study time. Most candidates spend 12 to 18 hours on Building Science and Systems. Adjust up if you don't see this work in your day job, down if you do.

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FAQ

Building Science and Systems questions.

The depth in soil where the ground freezes. Foundations must be below the frost depth to prevent frost heave. In Canada, this is typically 1200 to 1800 mm.

Place the dew point inside insulation, install a vapour barrier on the warm side, and limit air leakage with a continuous air barrier. The four control layers should each be continuous.

Passive ventilation relies on natural forces (wind, buoyancy). Active ventilation uses fans. Most Canadian buildings use mechanical ventilation because passive can't reliably deliver fresh air in cold climates.

12 to 18 hours. Pair Heating, Cooling, Lighting with the Building Envelope Thermal Bridging Guide for the best return.