Do I need a permit for addition or structural alteration in Mountlake Terrace?
Yes. In Washington, addition or structural alteration generally requires a permit, and Mountlake Terrace is no exception.
Additions must meet the Washington State Energy Code for new construction; additions over 150 square feet must also meet the additional energy efficiency credit requirements of Section R406 (WAC 51-11R-50200). Electrical work is permitted and inspected by L&I unless the address is in a city with its own electrical program. Owners may do their own work on their own property, but the permits and inspections still apply.
Documents you may need
- Permit applicationrequired
- Site plan with setbacks and lot coveragerequired
- Construction drawings (floor plan, framing, foundation, sections)required
- Washington State Energy Code compliance documentationrequired
- Structural engineering where required by the building officialSometimes required
- Separate electrical, plumbing, and mechanical permitsLikely required
Possible inspections
- Footing and foundation inspection
- Framing inspection
- Electrical, plumbing, and mechanical rough-in inspections
- Insulation inspection
- Final inspection
Frequently asked questions
- Do I need a permit for addition or structural alteration in Mountlake Terrace?
- Yes. In Washington, addition or structural alteration generally requires a permit, and Mountlake Terrace is no exception. The documents and inspections sections on this page list what the building department typically asks for.
- Who issues the permit in Mountlake Terrace?
- The local building department for Mountlake Terrace handles permitting. This page lists its contact details and online portal. Your mailing city is not always the permitting authority, so confirm the jurisdiction before you apply.
- How do I find out the exact requirements for my project?
- Run the free PermitRoadmap check for your specific project and answers. It returns the likely permits, documents, inspections, and next steps, each linked to its official source.
PermitRoadmap is an independent informational service and is not affiliated with any city, county, state agency, or permitting authority. Results are informational and do not replace confirming requirements with the local permitting authority.