Before a certified Ottawa home inspector ever sets foot inside a home, the exterior has already told them a great deal. The building exterior visual examination — the full perimeter walkthrough that opens every pre-purchase home inspection — is not a warm-up. It is one of the most information-dense stages of the entire process, and what an inspector finds outside directly shapes what they look for once they step through the front door.
In Ottawa's climate, the exterior of a home is under constant stress — freeze-thaw cycles, heavy snowfall, ice damming, wind-driven rain, and UV exposure all leave evidence that a trained eye knows how to read. Here is what we are assessing during the exterior walkthrough, and why each component matters.
I treat the exterior walkthrough like reading the first chapter of a book. By the time I finish the perimeter, I already have a working theory about what the inside is going to show me. Staining under a window, negative grading against the foundation, a cracked soffit vent — none of these are conclusions on their own, but together they build a picture I'm actively testing as I move through the rest of the inspection.
— Ottawa AAA Home Inspections
What Does the Exterior Walkthrough Actually Cover?
Roof — From the Ground and Sides
We assess the roof from the ground level and from all sides of the home, looking at the overall condition of the shingles or roofing material, the ridgeline, visible flashings, gutters, and any penetrations we can observe from grade. Where weather conditions allow, we use a drone for a full overhead view. The sides of the home often reveal shingle lifting, flashing separation at chimneys, and valley conditions that aren't visible from directly below — the kind of roof issues we regularly document across Ottawa homes.
Inside clue: Staining on the underside of roof decking in the attic confirms what exterior roofing issues suggest.Siding and Exterior Cladding
Whether the home has vinyl siding, brick, stucco, wood, fibre cement, or a combination, we're looking for damage, separation, missing sections, improper lapping, and any areas where the cladding has allowed or is likely to allow water to get behind it. In Ottawa, repeated freeze-thaw cycles are particularly hard on brick mortar joints and stucco — both of which can develop hairline cracks that admit water and then expand as that water freezes.
Inside clue: Exterior cladding failures often show up as interior wall staining, soft drywall, or mold behind finished surfaces.Windows, Doors, and Trim
We check every accessible window and door from the exterior — looking at the frame condition, caulking, flashing above the unit, and any staining on the cladding below. Failed caulking around window frames is one of the most common exterior findings in Ottawa homes, and it is also one of the most commonly overlooked by homeowners. Trim that is soft, cracked, or pulling away from the frame is another early indicator of moisture intrusion.
Inside clue: Staining or efflorescence on the interior wall below a window often traces directly to failed exterior caulking above it.Attic Ventilation Openings
Soffit vents, gable vents, and ridge vents are visible from the exterior and tell us important things about the attic's ventilation system before we ever open the hatch. Blocked, damaged, or missing soffit vents are a common finding — and they directly contribute to ice damming in winter and excessive heat buildup in summer, both of which shorten roof and attic component lifespan significantly.
Inside clue: Poor ventilation confirmed from the exterior is validated in the attic through condensation staining, frost on sheathing, or elevated moisture readings.Grading and Drainage
The slope of the ground around the home is one of the highest-leverage observations of the entire exterior walkthrough. The ground should slope away from the foundation at a minimum of 1 inch per foot for the first 6 feet — a standard set by OAHI. Where the grade has settled toward the home, water pools against the foundation wall during rain and snowmelt, and that water eventually finds its way in — exactly the mechanism covered in our guide to foundation cracks and drainage in Ottawa homes. This is especially relevant in Ottawa given the heavy clay content of local soils, which retains water rather than draining it quickly.
Inside clue: Negative grading is directly correlated with basement moisture, efflorescence on foundation walls, and musty odours in the lower level.Gutters, Downspouts, and Surface Drainage
Eavestroughs and downspouts are the first line of defence against roof water reaching the foundation. We check that they are securely attached, properly sloped, free of visible blockage, and that downspouts discharge water at least 1.8 metres away from the foundation — the same checklist item we walk homeowners through in spring basement cracks in Ottawa — or into an underground drain that we can confirm is functional. Granule accumulation at the base of downspouts also tells us about shingle condition before we've even assessed the roof surface itself.
Inside clue: Downspouts discharging directly against the foundation wall are a leading predictor of basement water intrusion.Foundation Walls — Visible Portions
Where the foundation is visible above grade, we assess the exposed concrete or masonry for cracking, spalling, deteriorated parging, and any signs of displacement or bowing — the same structural findings we document throughout the rest of the home. In Ottawa's soil conditions — particularly in areas with significant clay content — foundation movement is not uncommon, and the pattern and nature of cracks visible from the exterior can suggest whether movement is historic and stable or potentially ongoing.
Inside clue: Exterior foundation cracks are cross-referenced with what we find on the interior basement walls and floor slab.Visible Electrical Components
The electrical service entry — where the utility lines connect to the home — is assessed from the exterior. We look at the condition of the service entrance cable, the meter base, and the clearances from roof, windows, and grade. Mast and service entrance deficiencies are flagged here the same way we flag them in our electrical inspection findings, because they can be safety hazards and are sometimes a condition of home insurance coverage in Ontario.
Inside clue: Service entrance condition is connected to what we find at the main panel and overall electrical system assessment inside.Visible Plumbing Penetrations
Exterior plumbing penetrations — gas meter connections, hose bibs, and any visible drain or supply lines — are noted during the walkthrough as part of the broader plumbing assessment. Hose bibs that lack proper anti-siphon protection are flagged, as are gas meter areas that show signs of corrosion or improper clearances. Exterior drain outlets and sump pump discharge points are also checked to confirm they are directing water appropriately away from the home.
Inside clue: A hose bib with no shut-off on the interior supply line is a common finding that connects the exterior observation to the plumbing assessment inside.We walk the full perimeter of every home before entering — in all weather conditions where it is safe to do so. Where drone conditions allow, we supplement the ground-level exterior assessment with overhead drone footage that captures the full roof surface, flashings, and site drainage patterns not visible from grade. Every exterior finding is documented with photographs and referenced in the report alongside related interior findings, so you can see exactly how the outside and inside of the home connect.
Does the exterior walkthrough happen even in winter or bad weather?
Almost always, yes. The exterior is assessed in all conditions where it is safe to do so. Snow cover can obscure grading and some foundation details, which we note in the report. Drone roof inspection may not be possible in high winds, precipitation, or very low temperatures — in those cases we use binoculars or a pole-mounted camera from the ground and inspect the underside of the roof from the attic. Weather limitations are always disclosed in the report.
Book a Full Exterior and Interior Inspection in Ottawa
Ottawa AAA Home Inspections serves Ottawa, Gatineau, Barrhaven, Kanata, Orléans, Rockland, and surrounding areas. Every inspection includes a full exterior walkthrough, drone roof assessment where conditions allow, thermal imaging, and same-day report delivery.
Sources
- CAHPI — Canadian Association of Home and Property Inspectors, National Standards of Practice — cahpi.ca
- OAHI — Ontario Association of Home Inspectors, Grading and Drainage Standards — oahi.com
- Environment and Climate Change Canada — Ottawa Climate Normals — climate.weather.gc.ca