Lincoln, NE Accessory Structures: ADU Permits (2026)

Lincoln regulates accessory dwelling units (called ADUs or accessory apartments) through Title 27 of the Lincoln Municipal Code (Zoning), administered by the City-County Planning Department and Building & Safety Department. ADUs are permitted in R-1 through R-5 single-family and low-density residential districts subject to standards including: maximum floor area of 800 sq ft or 40% of the principal dwelling, whichever is less, for detached ADUs; maximum height of 22 ft or the height of the principal dwelling, whichever is less; minimum side setback of 5 ft and rear setback of 5 ft (matching accessory structure rules under §27.71); minimum one off-street parking space, with potential waiver near high-frequency transit corridors. Nebraska LB 866 (Neb. Rev. Stat. §19-925 et seq., enacted 2020) requires cities of the metropolitan and primary classes (over 50,000 population) — which includes Lincoln — to permit attached ADUs by-right on lots zoned for single-family use. The statute applies objective standards and limits discretionary review for attached units; detached ADUs may still be subject to local conditional-use review. Lincoln enforces the 2018 International Residential Code with Nebraska amendments through the Building & Safety Department. Frost depth (42 in. footing depth) and 25 psf ground snow load (per ASCE 7 for Lancaster County) are critical structural requirements.