Why the site plan matters
With a pre-approved plan, the building has already been reviewed. The site plan is what the reviewer checks against your zone, and it's where most corrections come from.
Drawing basics
- Scale (for example 1" = 20') and a north arrow
- Property address and parcel number
- Property lines with dimensions, from a survey or County GIS
- Streets, alleys and easements
Buildings and setbacks
- Existing house, garage, sheds and decks, with dimensions
- The proposed ADU footprint, labeled with plan name and square feet
- Dimensioned distances from the ADU to every property line and to other buildings
- Building height for two-story plans
Utilities and drainage
- Sewer or septic: the route to the main or the septic system and reserve area
- Water: meter location or well
- Power: route from the panel or a new service
- Stormwater: downspouts, infiltration or dispersion, and impervious area added
Site conditions
- Critical areas and buffers: wetlands, streams, steep slopes, shoreline
- Significant trees in the work area
- Topography or slope where grading is needed
Access and parking
- Driveway and access to the ADU entry
- Any required parking stall, with dimensions
- Fire access if the jurisdiction requires it
Calculations
- Lot area, building coverage and impervious coverage
- Floor area of the ADU (and of the main house where the code limits ADU size by ratio)
Our permit-ready package covers all of this, drawn to your jurisdiction's submittal checklist.