What is MiMo and why does historic review apply to my Upper Biscayne home?

MiMo (Miami Modern) is the post-World War II architectural movement that defined South Florida resort and motel design from roughly 1945 through 1972. The MiMo Biscayne Boulevard Historic District covers Biscayne Boulevard between NE 50th Street and NE 77th Street and was designated by the City of Miami Historic & Environmental Preservation Board (HEPB) in 2006 under City of Miami Code Chapter 23 (Historic Preservation). The district was added to the National Register of Historic Places in 2010.

For any property inside the district — and for individually designated MiMo landmarks elsewhere on the Upper Eastside, Miami Shores, and North Bay Village — a Certificate of Appropriateness (COA) under Chapter 23 Section 23-6.2 is required before a building permit will issue for any visible exterior change. "Visible exterior" is interpreted broadly:

• Roof material or color change.
• Window replacement (even hurricane-impact upgrades — must match original muntin pattern, frame profile, and glass tint).
• Front-yard landscape, walls, fences, paving.
• Signage and lighting fixtures.
• Additions, dormers, and rooftop equipment visible from the public right-of-way.
• Demolition of any contributing structure.

Review tracks under Chapter 23:

• Staff-level Certificate of Appropriateness for in-kind work and minor exterior repair. 2-4 week turnaround.
• HEPB hearing for additions, demolition, new construction, or any work not meeting the Secretary of the Interior's Standards for Rehabilitation. 6-14 weeks. HEPB calendar is the first and third Tuesday of each month with a 35-day filing cutoff.
• Special Certificate of Appropriateness for demolition under Section 23-6.2(b)(5) — requires HEPB plus City Commission appeal window.

Interior work that does not affect the exterior, structure, or designated character-defining features can usually proceed under a standard building permit without HEPB review. But any window upgrade, roof replacement, exterior paint, or addition triggers full COA. Penalties for unpermitted work in the MiMo district under Section 23-6.4 include daily fines, restoration orders, and a recordable lien on the property.