10.1 Building Envelope, Foundations & Framing Systems

Start with the building and its records

A foundation transfers building loads to the ground. Floors, walls and roofs carry loads to it. The enclosure controls rain, air leakage, heat flow and water vapour. At a showing, identify the assembly where it is visible, describe any symptom precisely and ask a qualified inspector what the symptom might mean. A crack, stain or sag can warrant investigation without establishing the cause or cost.

Alberta brought the National Building Code – 2023 Alberta Edition and the National Energy Code of Canada for Buildings 2020 into force on May 1, 2024. Alberta lists the second printings for current work as of November 2026. NBC(AE) Section 9.36 addresses energy efficiency for applicable housing and small buildings. Article 9.36.1.3 sets out routes by building type and application, including where the energy code can be used. Verify which requirements applied when the work was permitted and which apply to the proposed work. A municipal development approval addresses use and site rules. A building permit and related trade permits address their own safety-code work. Ask the authority for permit records, inspection status and any unresolved orders. An RPR and municipal compliance evidence address their own scope.

For a new home subject to Alberta’s mandatory warranty program, verify the builder and property in the provincial registries and read the policy. The minimum periods are one year for labour and materials, two for delivery and distribution systems, five for building envelope and ten for structural defects. The coverage stays with the home for the remainder of its term on resale. Check the documented start date, claims, repairs and any additional envelope coverage. Warranty coverage and approval of work are separate checks.

Identify foundation types and drainage risks

For wood-frame foundations, NBC(AE) Article 9.15.2.4 refers to CSA S406 or design under Part 4. Footing depth and frost protection under Article 9.12.2.2 depend on soil, drainage, building conditions and the approved design. A width measurement alone does not diagnose a crack. Record its location, direction and any displacement, staining or documented change. For example, an inward-bowing block wall with a horizontal crack deserves specialist review even if the basement has recently been painted.

Trace water from the roof and grading to its approved outlet. Gutters and downspouts direct roof runoff away from the wall. Grading and drainage help keep water from collecting at the foundation. A footing drain can carry groundwater to an approved outlet, sometimes through a sump and pump. Ask where the pump discharges, who maintains it and what happened during previous outages or heavy rain. Dampproofing reduces the entry of soil moisture. Waterproofing addresses conditions such as hydrostatic pressure where required. A drainage mat can form one component of the assembly. Verify the approved details before drawing conclusions about the wall’s waterproofing.

Follow the load path

In platform framing, each floor forms a platform for the walls above. In balloon framing, studs can run across multiple storeys and the floor framing is supported within that arrangement. Check required fire blocking at concealed cavities, junctions and penetrations. The presence of a floor platform does not verify the condition of those details. Engineered wood I-joists have a web and flanges. Laminated veneer lumber can carry loads at beams or headers. Trusses distribute loads to their designed bearing points. For a cut truss chord, altered I-joist or removed wall, obtain the plans, manufacturer details or an engineer’s assessment before advising on repairs or further alteration.

Distinguish four enclosure functions

In a conventional insulated cold-climate wall, warm-side vapour control helps limit condensation at colder layers. Polyethylene is one solution. Different assemblies can use other approved materials or place the vapour control within the assembly under applicable code provisions. A second low-permeance layer can limit drying. Ask about continuity, layer locations, exterior insulation and the approved design. R-value and RSI describe resistance to heat flow. Cavity insulation alone does not give the effective resistance of a wall with framing, windows and thermal bridges. Continuous exterior insulation can reduce thermal bridging. Check how it affects the drainage and drying of the proposed assembly.

Trace a roof leak and assess attic evidence

In a vented attic, vents and baffles help move outdoor air through the roof space while keeping insulation out of the ventilation path. Where the prescriptive venting rules apply, NBC(AE) Article 9.19.1.2 generally uses an unobstructed vent area of at least 1/300 of the insulated ceiling area. It uses 1/150 for roofs below a 1-in-6 slope or built with roof joists. Required openings are distributed on opposite sides, with at least 25% at the top and at least 25% at the bottom. Check the applicable assembly before applying those figures. Air sealing and insulation at the ceiling also help limit heat and moisture transfer from the home. Ice dams can form when snow melts higher on the roof and refreezes at a colder eave. Backed-up water can enter beneath the roofing. A leaky hatch, attic frost and eave ice together warrant investigation of the ceiling air barrier, insulation and roof drainage. Icicles alone do not diagnose a defect. On a sloped roof, assess the covering, underlay, flashing and penetration details for the actual slope. On a low-slope roof, check the specified membrane, drainage, seams and roof outlets.

Read visible finishes and windows

If a listing advertises new windows but the buyer sees damp trim, ask for the installation and warranty records and have the opening inspected. Record the feature and symptom separately so the buyer can compare repair scope, cost and energy performance.

NRCan guidance on window condensation · Alberta Health guidance on water-damaged finishes · Health Canada guidance on asbestos

Compare environmental performance claims

A home can use less energy or water through improved insulation and airtightness, efficient windows and equipment, or water-saving fixtures. Compare the benefit with installation cost, maintenance and suitability for the occupants. For example, air sealing can reduce drafts and heating loads while making properly designed ventilation more important. Window improvements can affect comfort and condensation, and their energy benefit depends on the original windows, installation and home. Lower-flow fittings can save water and, for hot water, energy. Ask about the actual fixtures and operating conditions.

For a claim such as “energy efficient,” request the dated EnerGuide report, equipment specifications or other applicable certification. EnerGuide’s standardized estimate allows comparison under common assumptions. Utility bills also reflect household habits and weather. Explain those limits before describing savings or a price premium.

NRCan EnerGuide results and assumptions · NRCan R-2000 environmental features

For a resale, verify the Alberta licences of both the home inspector and the home inspection business. Under the Home Inspection Business Regulation, a home inspection is primarily non-invasive and addresses readily accessible components. Check the written contract for scope, exclusions and the report due date. The written report identifies deficiencies and may recommend an expert opinion. The regulation restricts disclosure of the report, prohibits conflicts of interest and bars the business and inspector from giving a repair-cost estimate as a result of the inspection. Ask the appropriate specialist or contractor for the next assessment or cost estimate. Match any offer condition to the questions to be answered, needed access and a workable deadline. Verify known material latent defects through the duties explained in the disclosure chapter.