Find air leaks, bulk water and moisture before adding insulation.
Home system
Building envelope, condensation and layer order
Understand air, vapour, insulation, drainage and thermal bridges before closing a wall, attic or basement.
Checked: 2026-08-21
When the assembly changes, verify air/vapour continuity, drying potential and thermal bridges.
Hidden mould, decayed wood, recurring condensation or an unknown assembly: stop before enclosure and obtain analysis.
Useful tools and measurements
- Hygrometer and thermometer
- Thermal camera / diagnostic smoke where appropriate
- Moisture meter
- Visual inspection of joints and penetrations
Having a tool does not make regulated work DIY.
What the professional checks
- Trace air-water-vapour paths through the assembly
- Check layer continuity and drying potential
- Specify an assembly compatible with climate and existing construction
Sources and limits
Requirements vary with the building, jurisdiction, code edition and exact scope. This triage does not replace plans, calculations, permits, inspections or required professionals.
V19
Edge systems to integrate into the project
V19 covers interfaces that become important when multiple home systems interact.
V27
Project risks and overlooked interfaces
V27 connects payment, water, envelope, ventilation and jobsite details that often create costly surprises.
V31
Commissioning and everyday safety
V31 helps verify systems after work and document the values that make a home safer to operate.
Hidden junctions V53
V47
V47 interfaces not to miss
These details are small on a drawing but can control water, structure or durability.