Bay/bow window: support, insulation, air and flashing

A projecting window is also a small structural/enclosure assembly: support, roof/soffit, water, air, insulation and condensation must work together.

Decision triage

VERT / GREEN · JAUNE / YELLOW · ROUGE / RED

What the professional checks

The professional checks opening/header, brackets/cables/support, deflection, flashing, drainage, air barrier, insulation and condensation.

Official sources

Sources checked: 2026-08-24

Related path

Continue with the right tools

These links connect this page to the next useful checks and decisions without repeating the full content.

Connect symptoms to the enclosureStart from condensation, staining, odours or movement before choosing a repair.Open →Adapt the enclosure to climateConnect heat, cold, water, wind and wildfire to building priorities.Open →Assess overall resilienceReview water, climate, safety, autonomy and records with a local score.Open →Screen hazardous materialsIdentify situations where work should stop and testing is needed before disturbance.Open →Open climate guidanceReview climate constraints relevant to assemblies and materials.Open →
V14

Systems to check before closing the work

V14 connects envelope, air, fire, structure, water and code instead of treating each project in isolation.

Renovation dependenciesEnvelope and condensationLoad-bearing walls and openingsRoof penetrations and flashingCode versions
V15

Remaining system checks not to miss

V15 covers issues that can block a project, cause a loss or become expensive once concealed.

Before closing wallsPost-renovation commissioningCodes + climate by province
V18

Specialized diagnostics to verify

V18 connects systems that become costly or regulated when a primary project triggers them.

Basement window well + egress
V19

Edge systems to integrate into the project

V19 covers interfaces that become important when multiple home systems interact.

Skylight/tubular daylightingSIP/ICF
V26

Often-overlooked service interfaces

V26 connects systems that cross utility, plumbing, HVAC, envelope and metering boundaries.

Attic hatch and pull-down stairsExterior window shading and overheating
V27

Project risks and overlooked interfaces

V27 connects payment, water, envelope, ventilation and jobsite details that often create costly surprises.

Safety glazing, showers and guardsTemporary weather protection during renovation
V28

Finish and service details to verify

V28 connects small details that become costly once finishes are closed.

Attic soffit baffles and ventilation
V29

Household safety and compliance details

V29 connects smaller risks that often fall between finishes, appliances, plumbing and local code.

Sealant joints, backer rod and movementCorded window coverings and child safety
V30

Shared, access and specialized interfaces

V30 connects projects where multiple systems, owners or rules meet.

Windows in masonry openings
V31

Commissioning and everyday safety

V31 helps verify systems after work and document the values that make a home safer to operate.

Windows and child fall prevention
V32

Post-disaster and legacy systems

V32 connects contamination, storm damage, legacy materials and recommissioning before rebuilding.

Storm/tree impact: structure, re-entry and stabilization
V47

V47 interfaces not to miss

These details are small on a drawing but can control water, structure or durability.

Roof-wall kickout