Winters in Portland, OR and Vancouver, WA are no joke. Heavy rain, melting snow, and sudden cold snaps can expose even well-maintained homes to costly water damage. In 2024 alone, Oregon saw $47.6 million in property damage from winter weather events, with an arctic blast causing $72 million in damage across 16 counties. Washington ranks among the top 10 states for expensive winter weather damage, underscoring the need for proactive preparation.

But before you break ground, it's important to understand how zoning rules, permitting steps, design constraints, and utility logistics all shape your timeline and budget. This guide focuses specifically on non-ADU home additions in the Vancouver and Clark County area, giving you clear, locally relevant information to plan your project with confidence.