Wilmington, DE Building Setbacks & Zoning: Structure Height Limits (2026)
Key Facts
- Wood-frame height cap
- 3 stories
- Applies to
- 1-2 family & semi-detached homes
- Rowhouse limit
- 10 units or 3 stories
- Party walls
- 2-hour fire rating required
- Type 5B frame
- prohibited citywide
Summary
Wilmington's building code caps protected wood-frame (Type 5A) one- and two-family homes, semi-detached dwellings, and rowhouses at three stories: taller wood-frame construction isn't permitted under the city's amended IBC.
Section 504.4.1.1. One-family detached dwellings and one-family semi-detached dwellings, not exceeding three stories in height, shall be erected of protected frame construction (Type 5A). All structural elements shall meet the requirements of strength and rigidity as specified in chapter 16 and 23, and construction as listed in Tables 601 and 602 of the International Building Code. In one-family semi-detached dwellings, walls between the housing units shall be two-hour party walls and shall meet the requirements of the 2018 International Residential Code and the 2018 International Building Code.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 72).
Full Breakdown
Sec. 4-27 amends the adopted 2018 International Building Code's Chapter 5 height provisions. Section 504.4.1.1 caps one-family detached and one-family semi-detached dwellings built with protected wood-frame construction (Type 5A) at three stories, with structural elements meeting IBC Chapters 16 and 23 and Tables 601-602, plus two-hour party walls between semi-detached units. Section 504.4.1.2 applies the same three-story cap to rowhouses and townhouses, also limited to ten houses per group. Type 5B frame construction is prohibited citywide, and the Commissioner of Licenses and Inspection administers the code.
Violations & Fines
Building code violations carry a fine of $250-$1,000 for a first offense, $500-$2,500 for a second, and $1,000-$5,000 for a third or subsequent offense, with community service allowed in addition to or instead of the fine (Sec. 4-3).
Frequently Asked Questions
Can I build a 4-story wood-frame house in Wilmington?
Does the three-story cap apply to rowhouses?
Sources & Official References
Other rules in Wilmington
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