New Castle County, DE Zoning Overlays & Bonuses: Density Bonus Law (2026)
Key Facts
- Max density bonus
- 20% above base density
- MPDU set-aside
- half of bonus, up to 10%
- Applies to
- major subdivisions, no rezoning
- Base density basis
- site capacity calc, Articles 4-5
- Program
- Traditional Neighborhood Housing, Div. 40.07.500
Summary
New Castle County lets major subdivisions earn up to a 20% density bonus above base zoning capacity when developers voluntarily set aside Moderately Priced Dwelling Units, with MPDUs equal to half the bonus percentage.
MPDUs may be provided on a voluntary basis subject to the following provisions. A. Density bonus. Any major subdivision proposing dwelling units may receive a density bonus if such plan provides MPDUs. 1. The residential density incentive shall be up to twenty (20) percent of the base density... B. Set-aside. The number of MPDUs that shall be set-aside shall be based upon a percentage equaling fifty (50) percent of the density bonus. If the density bonus is twenty (20) percent, ten (10) percent of all dwelling units shall be designated as MPDUs.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 5).
Full Breakdown
Under UDC § 40.07.520, a major subdivision that is not seeking a rezoning may still qualify for extra density by voluntarily providing Moderately Priced Dwelling Units (MPDUs). The residential density incentive tops out at 20% above the base density, which the Department calculates using a by-right site capacity calculation under Articles 4 and 5 and Table 40.04.110. In exchange, the developer must set aside MPDUs equal to half the density bonus taken, so a full 20% bonus requires designating 10% of all units as MPDUs. This voluntary track sits alongside the mandatory MPDU rules in § 40.07.510 that apply to rezonings and variances seeking added density.
Violations & Fines
Building at the bonus density without deeding the required MPDUs breaches the approved land development plan; the Department can deny certificates of occupancy and require correction before final plan approval.
Frequently Asked Questions
Does New Castle County require affordable units for a density bonus?
How much extra density can a developer get?
Sources & Official References
Other rules in New Castle County
Compare New Castle County to another location·View the Delaware zoning overlays & bonuses overview
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