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Building Permit Glossary

Lot Coverage

The portion of the lot covered by buildings or roofs. Some jurisdictions include other impervious areas.

Site & zoningProperty measurements

Applies to

Additions · Garages · Sheds · Decks · Covered patios

Project example

A garage may meet every setback but push the combined house, garage, porch, and roofed accessory area over the district's maximum lot-coverage percentage.

Also called

building coverageimpervious coverage

Where this term shows up in permit work and how it affects the project

Coverage can eliminate an otherwise compliant footprint or trigger a smaller design, removal of another structure, or zoning relief.

If this term appears in a form, plan comment, or local ordinance, start with the building permit guide, compare it against the zoning permit guide, then use the permit guide directory to find the right local path.

Why it matters for approval

Why lot coverage matters in a permit file

Lot coverage limits how much of the zoning lot may be occupied by the building features named in the ordinance. The calculation is local: roofed porches, overhangs, decks, pools, sheds, and pavement may be included, excluded, or counted under a separate impervious-surface standard.

Where it appears in the permit process

  1. Rule interpretation

    The ordinance defines the denominator, counted improvements, exemptions, and maximum percentage for the district.

  2. Existing-condition inventory

    The applicant measures every existing feature that the definition includes, not only the principal house.

  3. Proposed calculation

    New and removed areas are shown by feature so the reviewer can reproduce the total and percentage.

  4. Zoning decision

    If the total exceeds the limit, the design must shrink, remove other coverage, or pursue whatever relief local law allows.

What you may need

  • Accepted zoning-lot area
  • Survey or site plan showing existing and proposed footprints
  • Area schedule identifying every counted feature
  • Formula showing existing, removed, proposed, and total coverage
  • Ordinance citation for exclusions or special counting rules

Where to get it or verify it

  • Use the official zoning definition and district table; do not substitute an online percentage summary.
  • Use a survey, architectural plans, or verified field measurements for footprint areas.
  • Ask zoning staff how unusual features such as open decks, eaves, pools, and permeable systems are counted.

Common mistakes that create comments or delays

  • Dividing only the new structure by the lot area
  • Confusing building coverage with impervious-surface coverage
  • Leaving existing sheds, porches, or roof overhangs out of the inventory
  • Rounding dimensions so aggressively that the reviewer cannot verify the result

What to do next

  1. Confirm the exact local coverage definition and maximum.
  2. Build an auditable inventory of existing counted areas.
  3. Add and subtract proposed work in a labeled calculation table.
  4. Resolve an overage before construction drawings and procurement are final.

Read the practical guides

Related permit paths

Related permit terms

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