Permit Answer · Basement Drawing / Basement Drawings

What Drawings Are Needed for a Basement Permit?

Basement permit drawings normally explain both what exists today and what will change. For many projects, that means an existing floor plan and a proposed floor plan, with sections, construction details, site information and coordinated structural, HVAC, plumbing or fire and life-safety information added as the scope requires.

Direct answer: For a basement permit, the core drawing set usually starts with accurate existing and proposed floor plans showing room names, dimensions, doors, windows, stairs, exits, plumbing fixtures and the work being changed. A second unit, walkout, structural alteration or major building-system change can add sections, construction details, a site plan, HVAC or plumbing information and structural design. The municipality may also need information about fire separations, ceiling heights, egress and other Building Code items. The final submission should match the actual basement project rather than relying on a generic drawing checklist.

Existing floor plan

Documents the current layout so the proposed changes are clear.

Proposed basement floor plan

Shows room uses, dimensions, exits, plumbing fixtures and the proposed work.

Sections and details

May be needed for stairs, fire separations, wall/floor assemblies or below-grade work.

Site and technical information

Can be required for new entrances/openings, second suites, HVAC, plumbing or structural changes.

Property and municipality still matter

This answer is a practical starting point, not a permit decision for every property. Zoning, existing conditions, applicable law, project size and the municipality’s current application guide can change what is required.

Related 828 Design service

Basement Permit Drawings & Secondary Suite Design →

Reviewed against current municipal permit guidance: August 2026. Requirements are confirmed for the actual property and project before design/submission.

Need drawings for this project?

Send the property address, what you want to build and any survey, existing drawings, photos or municipal comments you already have.