Energy code
Washington energy-code options for a new custom home
Energy-code compliance is not one product you buy at the end. It is a package of envelope, equipment, ventilation, and efficiency decisions that needs to agree across the plans.
Reviewed against official sources · August 2026Choose a coordinated package
The design team must document the required code path and selected efficiency measures. The right package depends on the house, fuel choices, mechanical system, glazing, and construction budget—not simply the option with the highest marketing appeal.
Decisions that affect the whole design
- Wall, roof, slab, and window performance.
- Heat-pump and water-heating equipment.
- Air sealing, ventilation, and duct location.
- Solar readiness or on-site renewable features when applicable.
Lock it before permit
Changing the energy strategy later can ripple through window orders, framing, electrical capacity, mechanical sizing, and permit documents. Ask for a one-page summary of the selected path before the permit set is complete.
Bellevue’s architectural plan checklist identifies the energy information that belongs in the plans.
Action plan
Choose and document the energy path early
- 1
Confirm the code edition applicable to the permit date with the architect or energy-code professional.
- 2
Compare at least two compliant packages using installed cost, operating cost, comfort, electrical capacity, and maintenance—not points alone.
- 3
Select envelope assemblies, windows, heat pump, water heater, ventilation, ducts, and any renewable features as one coordinated system.
- 4
Put the chosen credits and performance values on the drawings, schedules, specifications, and compliance forms consistently.
- 5
Before inspection, collect product data, commissioning records, air-leakage results, and other documentation required by the approved path.
Official resources