Implementation of the 2009 WSEC will take effect on January 1, 2011.
Commercial and residential structures will see new changes in how their energy is used. Significant changes will occur in space-conditioning systems, insulation and lighting. Specifics on residential changes may be found at WSU Energy Extension Program
and commercial details may be found at Northwest Energy Efficiency Council
Residential codes will encourage a more efficient use of energy through leak and blower door testing, duct sealing, higher insulation values, indoor and outdoor lighting fixture efficacy requirements, and compliance of all space-conditioning systems, which includes air handlers, outdoor condensing units of a split system air conditioner or heat pump, cooling or heating coil or furnace exchanger.