Council studies ‘missing middle’ housing options for Bloomington neighborhoods

City planning staff presented a proposal on Oct. 20 to add so‑called "missing middle" housing types to Bloomington’s zoning code and opened a council discussion on where and how those housing forms should be allowed.

Planner Dakota Castende told the council that "missing middle, often referred to as gentle density housing or clustered housing, is housing that ... falls in the middle between single‑family homes and larger apartment complexes," and that the city is exploring standards for triplexes, fourplexes, detached townhomes, cottage courts and multiplexes (defined in the staff draft as structures with five to 16 units).

Staff said the planning goal is to increase housing variety and supply — particularly housing types that can serve people who live alone, small households and older residents who want to age in place — while ensuring new forms fit neighborhood context. Zoning performance standards under discussion include reduced setbacks, density thresholds, parking requirements, maximum unit floor area (for cottage courts), building height limits and impervious‑surface caps.

On parking, staff proposed several options and reported the planning commission and Housing and Redevelopment Authority recommended a less restrictive approach for many building types: one space per unit with no required garage (option B in staff materials) for triplexes, fourplexes, multiplexes and cottage courts, and the city’s existing townhome parking standard for detached townhomes. Council Member Carter said she preferred option B and that the market should help determine design choices.

Council members raised policy tradeoffs and neighborhood context repeatedly. Several members urged treatment sensitive to location: permitting higher density types by right in medium‑density zoning districts (R‑3, R‑4, RM‑12) while keeping triplexes and fourplexes conditional in low‑density R‑1 areas. Council Member Lowman urged the city to "reimagine" R‑1 in strategic places — pairing denser housing near transit corridors and keeping lower‑scale housing deeper in neighborhoods. Staff noted rezoning to R‑3 or R‑4 would be discretionary and potentially costly, and said making missing‑middle types a conditional use in R‑1 would add process (a conditional‑use permit) that might deter some applicants but provide more review.

Staff flagged practical design differences for Bloomington: unlike cities with alley networks, most new missing‑middle development in Bloomington would be front‑loaded with driveways leading to garages at sides or rear, which affects impervious surface and setback planning. For cottage courts, staff said the typology emphasizes smaller dwelling footprints oriented around a shared courtyard and that cottage courts likely would involve a homeowners association or a common lot and could be rental or owner‑occupied.

Council members asked whether accessory dwelling units (ADUs) would be allowed on lots with missing‑middle development; staff said the proposal remains flexible and would likely allow ADUs in some configurations but that the details require further drafting to avoid exceeding density thresholds or impervious‑surface limits.

Staff said additional work will refine minimum lot sizes, setbacks and parking standards and return options to the council; the planning commission’s recommendations were mixed on some specifics, while the HRA generally favored broader permission in more districts.

If approved, the zoning amendments would be folded into a code update with implementation details and design standards to be decided by the council in subsequent hearings.