Construction, Building Systems and Home Inspection
What this domain tests
This domain tests practical knowledge of how a house is built and how its systems fail, so a registrant can recognize red flags and interpret inspection findings. Questions cover structure, envelope, mechanical systems, and the limits of what an inspection covers.
Core rules and concepts
- Structure. Foundations may be poured concrete, block, or preserved wood. Cracks, settlement, and bowing walls signal movement. Floor and roof framing includes joists, beams, and trusses; notches and holes in members must respect limits.
- Building envelope. The envelope controls water, air, vapour, and heat. Key components are roofing, flashing, siding, windows, and the drainage plane. Most water damage comes from failed flashing, grading, or roof details, not from the wall assembly alone.
- Moisture and mould. Grading should slope away from the house; downspouts should discharge away from the foundation. Basement dampness often traces to roof water and poor grading.
- Mechanical systems. Electrical service has an amperage rating; aluminum branch wiring, knob-and-tube, and missing GFCI protection are common concerns. Plumbing includes supply, drain, waste, and vent; a venting defect causes slow drains and odours. Heating systems include forced air, hydronic, and heat pumps; combustion appliances need proper venting and carbon monoxide protection.
- Insulation and ventilation. Insulation resists heat flow; ventilation controls moisture and indoor air quality. Poor attic ventilation causes ice damming and condensation.
- Inspection scope. A standard home inspection is visual and non-invasive. It does not open walls, guarantee future performance, or replace specialist inspections for septic, well, or structural engineering.
Worked example
An inspector reports efflorescence on a basement wall and a downspout discharging beside the foundation. What is the likely cause and remedy?
Reasoning: efflorescence is salt deposit left by water moving through masonry and evaporating. Combined with a downspout discharging at the wall, the likely cause is roof water saturating the soil against the foundation. The remedy starts with extending the downspout and correcting grading, then sealing and monitoring. This is not proof of structural failure, but it is a moisture red flag that should be investigated before conditions are removed.
Traps that cost marks
- Treating a home inspection as a warranty or as an engineering assessment.
- Assuming basement cracks always mean structural failure, or never do.
- Ignoring grading and downspouts when diagnosing wet basements.
- Assuming a newer roof or furnace eliminates all related risks; installation quality matters.
- Forgetting that septic and well systems need separate specialist inspection.