Old Towne Orange · Historic property owners

The Mills Act and Orange's new historic ordinance

Plain-language updates on the property tax program for historic homes, and on the citywide preservation ordinance the City of Orange is drafting now.

Kept by Justin Ladd, Historic Homes Orange County · Seven Gables Real Estate

Videos & updates

Latest from Historic Homes OC

Short videos, meeting recaps and news on the ordinance and the Mills Act as the process moves forward.

The basics

What the Mills Act is

A 1976 California law that lets cities give owners of qualified historic properties a property tax reduction in exchange for a long-term promise to preserve and maintain the building.

Voluntary

Owners choose to apply. The city decides whether to offer a contract, and approval is never guaranteed.

10 years

The minimum contract term. It renews automatically each year unless the owner or the city gives notice.

Runs with the land

The contract is recorded against the property, so it passes to the next owner when the home sells.

How the savings work

Instead of taxing the home on its Prop 13 value, the County Assessor values a Mills Act property with an income-based formula set by state law. For many historic homes that produces a lower assessed value and a lower tax bill.

The benefit depends on the property. Owners who bought recently, at today's prices, tend to see the biggest difference. A home with a very low base-year value may see little or none. The Orange County Assessor can estimate savings before you commit.

What owners agree to

  • Preserve and maintain the property to the Secretary of the Interior's Standards and the State Historical Building Code.
  • Follow a rehabilitation plan for the exterior work listed in the contract.
  • Allow periodic inspections and report on work completed.
  • Interior remodeling is generally not restricted.

Ending a contract with a notice of nonrenewal phases the tax benefit out over the remaining years of the term. A city can cancel for breach, which carries a penalty set by state law.

City of Orange

Orange's Mills Act program

The City Council created Orange's program in 1998. Old Towne is the largest National Register historic district in California, so the program matters to a lot of homeowners here.

Applications are on hold. The city has paused new Mills Act applications while it reviews the program. The draft Mills Act Program Guidelines were reviewed alongside the new preservation ordinance in August 2026, so the rules for new contracts are likely to change when the ordinance is adopted.

Existing contracts still apply. Current Mills Act owners in Orange file an annual report on repairs and maintenance, and update the rehabilitation plan (Exhibit D of the contract) every ten years.

Buying a Mills Act home? Ask for a copy of the recorded contract and the rehabilitation plan. The work obligations and the lower tax bill both transfer to you, and the tax bill you inherit may not match what the seller paid.

Who to call

City of Orange Community Development, Historic Preservation
300 E. Chapman Ave., Orange, CA 92866
(714) 744-7220

Orange County Assessor, for a savings estimate
(714) 796-8048

In progress

Orange's new Historic Preservation Ordinance

Orange has protected Old Towne through a historic district zoning overlay and design standards, without a standalone preservation ordinance. The city is now writing one, with consultant Chattel, Inc.

What it would cover

  • Properties in the Old Towne and Eichler historic districts.
  • Historic properties outside a district that are on the city's Inventory of Historic Resources.
  • Properties that could qualify for historic status.
  • Archaeological, paleontological and tribal cultural resources.
  • Criteria and steps for designating landmarks and districts, and a local register.
  • A tiered review system, meant to streamline smaller projects.
  • A new Historic Resources Committee that would replace the Design Review Committee.
  • The Mills Act program.
  1. Council limits design review, calls for an ordinance

    Council narrows Design Review Committee review to historic properties and directs staff to finish a citywide ordinance with a consultant.

  2. Study session

    Joint Planning Commission and Design Review Committee session on the ordinance's scope.

  3. Community workshop

    Public workshop at the Orange Public Library to gather input.

  4. Draft reviewed

    Design Review Committee reviews the draft ordinance and the Mills Act Program Guidelines.

  5. Revised draft out for public review

    Hearings before the Planning Commission and City Council are expected in the coming weeks.

Questions

Common questions

Can I apply for the Mills Act in Orange right now?

Not yet. The city has paused new applications while it reviews the program. Watch City Council and Planning Commission agendas, or check back here for updates.

Does the Mills Act restrict what I can do inside my house?

Generally no. The contract focuses on preserving the historic character of the property, mainly the exterior. Interior remodels are usually not covered.

If I buy a home with a Mills Act contract, does it stay in place?

Yes. The contract is recorded against the property and binds each new owner, including the maintenance and rehabilitation commitments.

How much will I save?

It varies with the property and its current assessed value. The Orange County Assessor can give you an estimate before you apply.

Will the new ordinance affect my home if it isn't in Old Towne?

It could. The draft reaches historic properties on the city's inventory outside the districts, and properties that could qualify for historic status. Review the draft or ask the city how your address is treated.

How can I weigh in on the ordinance?

Read the draft on the city's Community Development page, send comments to Community Development, and speak at the Planning Commission and City Council hearings when they are scheduled.