Skip to content

Tustin · Building on your lot

Building on a hillside in Tustin

Outside the East Tustin Specific Plan, hillside review applies to cut or fill of 3 feet or more or grade averaging 20% or more.

Ask about building on a hillside in Tustin See coverage

Key points

  • Hillside review: Outside the East Tustin Specific Plan, hillside review applies to cut or fill of 3 feet or more or grade averaging 20% or more.

Each rule below links to the section of the Tustin Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What Tustin's code says

Tustin code What Tustin's code adds
Soils or geology report
  • An independent engineering study of slope instability, liquefaction, landslide and seismic potential.
    Applies: Proposed development in a Geologic Hazard Special Study Zone.
    § 8915 · code text
    Provision and approval of an independent engineering study concerning the potential impact of slope instability, liquefaction, landslide and seismic potential for proposed development within a Geologic Hazard Special Study Zone.
Grading and retaining walls
  • Hillside review is needed for cut or fill of 3 feet or more in height.
    Applies: Sites outside the East Tustin Specific Plan; review comes before the grading or building permit.
    § 8915 · code text
    Outside the East Tustin Specific Plan, provisions to any development Site where the average existing grade is twenty (20) percent or greater, a site which entails cut and/or fill grading of three (3) feet or more in vertical height below or above natural ground, or a combination of fill-over-cut slopes equal to or greater than five (5) feet in vertical height
  • Hillside review is needed for combined fill-over-cut slopes of 5 feet or more in height.
    Applies: Sites outside the East Tustin Specific Plan; review comes before the grading or building permit.
    § 8915 · code text
    Outside the East Tustin Specific Plan, provisions to any development Site where the average existing grade is twenty (20) percent or greater, a site which entails cut and/or fill grading of three (3) feet or more in vertical height below or above natural ground, or a combination of fill-over-cut slopes equal to or greater than five (5) feet in vertical height
When hillside rules apply
  • An average existing grade of 20% or more.
    Applies: Sites outside the East Tustin Specific Plan; triggers hillside review before a grading or building permit.
    § 8915 · code text
    Outside the East Tustin Specific Plan, provisions to any development Site where the average existing grade is twenty (20) percent or greater, a site which entails cut and/or fill grading of three (3) feet or more in vertical height below or above natural ground, or a combination of fill-over-cut slopes equal to or greater than five (5) feet in vertical height

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What extra rules apply to a hillside lot in Tustin?

Outside the East Tustin Specific Plan, hillside review applies to cut or fill of 3 feet or more or grade averaging 20% or more.

General information, not legal advice.

Ask about a specific Tustin property

Ask GoCodebook how Tustin's building on a hillside rules apply to your situation and get an answer that cites the section.

Ask your question

More on building on your lot in Tustin

All building on your lot rules in Tustin

Solar panels and EV chargers in Tustin

Noise and construction hours in Tustin

Home alarm permits and false alarms in Tustin

Tustin Municipal Code — full text