Zoning › State preemptions › District of Columbia

DC Inclusionary Zoning Plus — deeper affordability overlay (DC)

Tracked preemption from the District of Columbia overlay bundle.

Overview

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Effective
2019-01-01
Sunset
—
Authority
district
Scope
state:DC
Other District of Columbia preemptions
NCPC Submission Guidelines — tightened federal review staging (in force 2026-01-08)New York Avenue (NYE) text/map amendments — fixed 8% IZ set-asideComprehensive Plan Amendment Act of 2021 — District Elements + NCPC Federal ElementsZR 2016 — Zoning Regulations of 2016 (11 DCMR)DC Inclusionary Zoning — mandatory citywide IZ (ZR 2016 Subtitle C Ch. 10)DC Home Rule Act of 1973 — Congressional review & §602(a) reserved mattersNCPC — federal review of DC projects affecting federal interestDC Zoning Enabling Act — Zoning Commission jurisdiction and federal-appointee structure

Trigger predicate

When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.

AND
  • parcel.iz_plus_overlay == True
  • OR
    • project.unit_count ≥ 10
    • project.residential_gfa_sf ≥ 10000

Preempted fields

2 fields on the base district schema are rewritten when the trigger fires.

FieldOpValueNote
affordability_tier_mficap_at50IZ Plus zones deepen affordability to 50% MFI instead of 60/80% MFI
iz_plus_penthouse_obligationoverridereserve_at_50_mfi_or_hptf_payment_half_market_valueDecember 2024 ZC action — penthouse residential GFA must either reserve units at 50% MFI within the penthouse or pay HPTF (Housing Production Trust Fund) in-lieu equal to half the penthouse market value

Citation

Authority source
Zoning Commission action (2019) creating IZ Plus; expanded to penthouse/rooftop habitable space by ZC action December 2024
§ 11 DCMR Subtitle C, Chapter 10 (IZ Plus subzones); Dec 2024 ZC penthouse expansion
https://dhcd.dc.gov/page/inclusionary-zoning-iz-program

Research notes

IZ Plus is layered on top of base IZ in select high-opportunity zones. December 2024 ZC action extended IZ Plus to penthouse / rooftop habitable space, adding the HPTF in-lieu-payment alternative at half the penthouse's market value. Per-project records should carry an iz_plus_penthouse_obligation field.