Historic Buildings and the Built Environment

When it is old enough to be considered and the project could affect it. For federal undertakings, the working convention is that buildings and structures reaching 50 years of age get evaluated, because Criteria Consideration G makes younger properties eligible only on a showing of exceptional importance. For CEQA, there is no age threshold at all, so a lead agency can require evaluation of a younger resource, and 14 CCR 4852 expressly allows listing resources under 50 years old.

The trigger is broader than demolition. Alteration inconsistent with the Secretary of the Interior’s Standards, relocation, and changes to the setting can all be effects, so a project that only touches a historic building’s surroundings may still need the analysis.

Practical scoping note: buildings are usually the cheapest part of a cultural resources scope to resolve early, because the record research is above ground and does not depend on excavation. Getting the built-environment evaluation done in the feasibility phase is often what tells you whether a design will work.

Section 4(f) of the Department of Transportation Act, at 49 U.S.C. 303 with regulations at 23 CFR Part 774, protects publicly owned parks, recreation areas, and wildlife refuges, and all historic sites, whether publicly or privately owned. It applies to projects with Department of Transportation approval or funding, which in California usually means Federal Highway Administration, Federal Transit Administration, or Federal Railroad Administration involvement.

Section 4(f) is substantive, and this is the distinction that matters most. Section 106 requires an agency to consider effects. Section 4(f) prohibits the use of a protected property unless there is no feasible and prudent avoidance alternative and the project includes all possible planning to minimize harm, or unless the impact is de minimis. Where more than one alternative would use protected property, 23 CFR 774.3(c) requires a least-overall-harm analysis.

For anyone scoping a transportation project, Section 4(f) is the provision that can force a design change, while Section 106 shapes the record.

It is the streamlined path at 23 CFR 774.3(b), and for historic sites it depends entirely on the Section 106 outcome. Section 774.17 defines de minimis for a historic site as a determination, made in accordance with 36 CFR Part 800, that no historic property is affected or that the project will have no adverse effect. Section 774.5(b)(1) additionally requires consultation with the parties identified under Part 800 and written concurrence from the pertinent SHPO or THPO in that finding.

The consequence is worth planning around. Once an adverse effect is found under Section 106, there is no route to a de minimis finding for that historic site. The standard for parks, recreation areas, and refuges is different and independent, requiring a determination that the impact will not adversely affect the features, attributes, or activities qualifying the property for protection, with concurrence from the official with jurisdiction after public review.

Possibly, and it is a question worth watching rather than a conclusion. The de minimis definition at 23 CFR 774.17 is keyed to specific Section 106 finding language, “no adverse effect” and “no historic properties affected.” Reporting on the draft Section 106 rewrite describes replacing that findings architecture with a single agency report and a memorandum of decision.

If that happens, the cross-reference in the Section 4(f) regulations would no longer point at anything, which would likely require separate Federal Highway Administration rulemaking to fix. Neither FHWA nor the Advisory Council has said anything about this, so treat it as an open question. For a transportation project reaching a de minimis determination in the next year or two, it is a reason to document the finding under the current rules rather than waiting.