A window belongs to a wall
The new assembly must work with the surrounding wall’s water, air and thermal control layers. Ask the installer to describe those connections for your actual cladding and construction. A generic sealant promise is not enough to explain how water is kept out or safely directed back outside.
Discuss the sill before the trim
Ask how the sill is prepared, how incidental water can leave the opening and how the product’s drainage paths remain clear. The method should follow the manufacturer’s instructions and the project’s applicable design requirements. Do not instruct a crew to seal every visible gap without knowing whether it serves a drainage function.
Make the head and jambs understandable
The upper and side connections should be explained together with the existing wall system. Ask what cladding must be disturbed, how flashing is integrated and which exterior finishes are restored. Masonry, stucco and siding do not automatically accept the same detail. For complex or damaged envelopes, confirm whether design input is needed before quoting installation alone.
Document the concealed work
Request photographs of agreed opening preparation and perimeter details before they are covered. Keep them with the opening schedule and warranty. At handover, check that the finished appearance matches the scope without treating attractive trim as proof of the concealed work. If the wall condition changes the plan, obtain the revised detail and authorization in writing.
Questions worth asking
- What is the intended drainage path?
- How does flashing join the existing wall?
- Which cladding and trim are disturbed?
- Will concealed details be photographed?
Further reading
Natural Resources Canada: upgrading windows and exterior doors ↗Source checked October 16, 2026. Current requirements and eligibility need separate project-specific verification. This guide is an original planning explanation, not a product certification or installation instruction.
