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Publisher: Quantum Steel Design LLC
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Project guide

# Home Addition Permit and Plan Review Guide

Room additions combine zoning, site planning, structural design, energy compliance, utilities, trade permits, and inspections from excavation through final occupancy approval.

Published by [Quantum Steel Design LLC](https://www.homepermitprimer.com/about/). [Editorial methods and source-review scope](https://www.homepermitprimer.com/editorial-policy/).

## Do I need a permit?

Almost always required for new conditioned floor area, attached additions, bump-outs, new stories, and enclosed spaces that change the building footprint or use.

Confirm the answer for your property and exact scope with the building and zoning offices. A product size or a contractor's opinion alone does not establish an exemption.

General planning sources reviewed September 26, 2026. General planning guidance checked against the sources below. Municipal examples apply only in the named jurisdiction; they do not establish the rules for your address. Fees, processing times and adopted codes must be confirmed locally.

## Decisions to make before buying materials

- Start with the complete proposed footprint and use, including porches, roof extensions and added bedrooms. This lets reviewers identify the approvals that precede construction drawings.

- Ask what existing-house information is required where new work connects to old work. Record any flood, slope or utility constraint before finalizing the design.

## Common permit triggers

- Expanding the building footprint

- Adding conditioned or habitable space

- Adding a bedroom or bathroom

- Changing roof, foundation, or load-bearing structure

- Connecting new electrical, plumbing, or HVAC systems

## Documents to gather before applying

- Boundary survey and site plan

- Existing and proposed architectural plans

- Structural drawings and calculations

- Energy-code documents

- Utility, drainage, and trade plans

## Inspection sequence and hold points

- Footing and foundation inspections

- Underground utility inspections

- Framing and trade rough-ins

- Insulation and energy inspections

- Final building, trade, and occupancy approvals

Before each stage, ask what must remain exposed, who requests the inspection, and what approval is needed to continue. Keep corrections and final inspection results with the approved plans.

## Fees and scheduling

### Build a local fee estimate

Request a written fee estimate covering building review, trades, utility capacity and any impact or land-use charges.

### Plan the review sequence

Track zoning, site review, structural review and trade approvals separately; ask which must finish before permit issuance.

## Questions for the permit office

- Which property restrictions affect the proposed footprint and height?

- What drawings must show the connection to the existing structure?

- Are utility or septic approvals prerequisites to building-permit issuance?

## Mistakes that create delays

- Designing before checking setbacks and lot coverage

- Leaving utility capacity until late review

- Starting excavation before plans are approved

- Failing to coordinate trade drawings with architectural plans

## State and city variation

Energy codes, wind, seismic, snow, wildfire, floodplain, impact-fee, utility, and contractor requirements vary substantially by location.

## Questions for a contractor

- Who applies for each building and trade permit, and who is named as the responsible contractor?

- Does the written scope match every part of the permit application?

- Who responds to plan-review comments and pays correction or reinspection charges?

- Which inspections happen before concrete, backfill, drywall, or finishes conceal the work?

- What approved plans and final records will I receive at completion?

## Official references and examples

- [Portland: residential addition applications (local example)](https://www.portland.gov/ppd/residential-permitting/home-projects/additions)

These references explain the planning issues and examples discussed here. A rule in a cited city applies in that jurisdiction; it is not a nationwide requirement.

## Make this guide usable on your project

Create a checklist, track your next steps, and print or download it. No account or email address is needed.

[Plan this project](https://www.homepermitprimer.com/tools/project-planner/#home-addition-permit)[Find local guidance](https://www.homepermitprimer.com/local/)[Explore approvals](https://www.homepermitprimer.com/tools/permit-navigator/)[Prepare an application packet](https://www.homepermitprimer.com/tools/application-packet/)