Maryland Transfer of Development Rights (TDR) — Enabling & MoCo/Calvert Programs (MD)
Tracked preemption from the Maryland overlay bundle.
Overview
← All state preemptionsMaryland overlay roll-upMaryland zoning wikiMaryland building codesFederal overlaysGlossaryFederal-conflict: Not flagged
Effective
1980-10-01
Sunset
—
Authority
state
Scope
state:MD
Other Maryland preemptions
Maryland Land Use Article — Zoning & Planning Enabling AuthorityMaryland Historic District Enabling Authority (LU §8-201)Maryland Military Installation Joint Land Use Studies (LU §22-301)Atlantic Coastal Bays Critical Area — Worcester County OverlayMaryland Priority Funding Areas (PFA) — Smart Growth ActMaryland Rural Legacy Program — Designated Rural Legacy AreasMaryland Forest Conservation Act (FCA)Maryland Wetlands of Special State Concern (WSSC) & Nontidal Wetlands
Trigger predicate
When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.
OR
parcel.in_tdr_sending_area==Trueparcel.in_tdr_receiving_area==True
Preempted fields
2 fields on the base district schema are rewritten when the trigger fires.
| Field | Op | Value | Note |
|---|---|---|---|
base_districts[*].tdr_density_bonus | add | tdr_program_specific_bonus_density | Receiving-area parcels may achieve density above base zoning by purchasing TDRs from sending-area landowners; per-TDR density yield is program-specific (e.g., MoCo Agricultural Reserve: 1 TDR = 1 additional dwelling unit subject to receiving-zone caps). |
base_districts[*].max_units_per_acre | cap_at | sending_area_baseline | Sending-area parcels' development potential is reduced (typically to 1 du/25 ac in MoCo Agricultural Reserve) once TDRs are severed and transferred; restriction recorded as deed covenant. |
Citation
Authority source
Md. Code Ann., Land Use §7-101 (general TDR enabling); county programs codified in local zoning (MoCo Ch. 59, Calvert County Zoning Ordinance, Caroline, Charles, Howard, Queen Anne's, St. Mary's)
§ §7-101 (transfer of development rights)
Research notes
TDR is generally a locally-administered tool delegated through LU §7-101. Maryland is home to one of the nation's longest-running and largest TDR programs: Montgomery County's Agricultural Reserve TDR program (since 1980), preserving ~93,000 acres through transfer of development rights from rural sending areas (RDT zone) to receiving areas in suburban-core sectors. Other active programs: Calvert County (one of the earliest, 1978), Caroline, Charles, Howard, Queen Anne's, St. Mary's. Often stacks with MALPF easements and Critical Area growth-allocation. Sending areas typically agricultural or RCA-classified; receiving areas typically suburban-residential or commercial.