Marin County, CA Historic Preservation: Historic-Cultural Monuments (2026)
Key Facts
- Governing chapter
- Marin County Code Ch. 19.23
- State authority
- Health & Safety Code §§ 18954-18955
- Designating body
- County architectural commission
- Registry
- Register of architecturally significant structures
- Program type
- Voluntary alternative building standards
Summary
Marin County Code § 19.23.020 defines and registers "architecturally significant" structures and features, a locally designated status that unlocks voluntary alternative building standards for their preservation rather than a mandatory landmark-protection scheme.
(a)Architecturally significant structure is any existing or future structure or property, collection of structures, and their related sites deemed to have present or future local importance to the history, architecture or culture of an area pursuant to California Health and Safety Code Section 18955 and inventoried along with its significant features within the Marin County register of architecturally significant structures. (b)Architecturally significant features are the specific character-defining architectural features of an architecturally significant structure that are determined to have local importance by the County, pursuant to California Health and Safety Code Section 18955, and expressly inventoried with the structure within the Marin County register of architecturally significant structures.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 2026 Update 1).
Full Breakdown
23, adopted by Ordinance No. 3658 in 2016, is Marin's local equivalent of a cultural-monument program, built around California Health and Safety Code §§ 18954 and 18955, which let counties adopt the State Historical Building Code (Part 8, Title 24, California Code of Regulations) for qualifying properties. Designation is not automatic: a structure or feature must first be recognized by the county architectural commission and then inventoried in the Marin County register of architecturally significant sites, structures and features before the chapter's alternative rules apply to it.
030. 040 once approved work is complete and inspected. 060 additionally requires added-cost fire-life safety upgrades, smoke and carbon monoxide alarms, water heater seismic anchorage, ember-resistant attic venting, code-compliant exterior openings, and a gas shut-off device, on any addition or remodel to a listed structure, up to twenty percent of the project's valuation. This is a preservation-facilitation ordinance, not a demolition-control or landmark-alteration-review ordinance: it exists to make it easier, not harder, to keep a locally significant building standing.
Violations & Fines
Work on a listed architecturally significant structure that departs from the alternative regulations without building official approval loses the benefit of Chapter 19.23 and must instead meet the full current California Building Standards Code; unpermitted work remains subject to Marin's standard building code enforcement and permit penalties under Title 19.
Frequently Asked Questions
How does a building become "architecturally significant" under this chapter?
Does listing a building here stop an owner from remodeling it?
Are extra fire-safety upgrades required for these buildings?
Sources & Official References
Other rules in Marin County
California rules heatmap·Compare Marin County to another location·View the California historic preservation overview
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