Rental conversions in Wilmington

Wilmington's R-3 zoning district is meant to keep row-house blocks that have not been converted to two or more families in one-family use.¹⁰ A second apartment isn't among the uses that district lists, so ask the city's zoning office what route, if any, exists for your lot before paying for plans.

In Wilmington's R-4 district, row houses with conversions, turning a one-family dwelling into a two-family one needs zoning board of adjustment approval, a lot of at least 1,800 square feet and at least 1,500 square feet of gross floor area, and the board must find it won't hurt the neighborhood's character or worsen parking.¹¹ In the R-4 district, converting a three-story building that houses one or two families for more than two families needs board approval and at least 600 square feet of lot area and 500 square feet of livable floor area for each family.¹¹

An application to convert a Wilmington single-family house to multi-family use must include a licensed realtor's affidavit that the property was actively marketed as a single-family home for at least six months, unless the zoning administrator waives it, plus an affidavit that city taxes and water and sewer bills are current, and scaled plans.¹² In Wilmington, a building designed as a single-family house that was converted to multi-family use and has sat vacant for a year or more may not go back to multi-family use, though it may still be used as a single-family home.⁶

New Castle County's zoning code allows only one accessory dwelling unit per single-family detached lot, built inside the house or as an attached addition; on a lot of at least half an acre, one freestanding accessory building may be used as the unit if it meets the main house's setbacks.¹³ Under the county code, the owner must live in either the main house or the accessory unit as a principal residence, file an owner-occupancy affidavit with the building permit application and record a deed document saying so before the permit is issued; once the unit exists, the house may not be converted to apartments and only one of the two units may be rented.¹³

A New Castle County accessory unit needs one more off-street parking space than the house already requires and enough sewer or septic capacity, and if it will be rented it must be registered under the county rental code before the certificate of occupancy is issued.¹³ New Castle County's residential addition and renovation permit covers finished basements, decks, porches, sunrooms and attached accessory dwelling units, while a detached accessory unit is permitted as a single-family dwelling.¹⁶

New Castle County allows a single-family detached house to be converted into two or more apartments only if the house is at least 50 years old (or already had a board-approved special use), the lot is at least 120 percent of the district minimum, at least half the lot stays open, the existing house has at least 4,000 square feet of floor area and each apartment has at least 800 square feet.¹⁴ Few suburban houses clear all of those limits, which is why the accessory unit is the usual route outside the city.

The 2021 IRC requires the units of a two-family dwelling to be separated by walls and floors with at least a 1-hour fire-resistance rating, or a 1/2-hour rating if the building has an automatic sprinkler system throughout.¹⁷ The 2021 IRC requires at least one egress door for each dwelling unit, reached by a continuous path that does not pass through a garage, and opening to a public way or a yard or court that leads to one.¹⁷ A cellar apartment whose only way out runs up through the main house won't meet that.

The 2021 IRC requires smoke alarms in each sleeping room, outside each separate sleeping area and on every story including basements, interconnected within each dwelling unit so that one sounding sets off all of them.¹⁷ Under the 2021 IRC, a building or part of a building can't be occupied, or changed to a new occupancy, until the building official issues a certificate of occupancy.¹⁸

The City of Wilmington requires rental property owners to apply for and keep a Residential Property Rental License each year, and every rental property, including a newly acquired one, must be registered with the Department of Licenses and Inspections.¹⁵ Wilmington's housing code requires anyone who rents out a dwelling to have it inspected by the Department of Licenses and Inspections every two years for a building of five or fewer units and every five years for six or more, starting with an initial rental inspection on the commissioner's schedule.¹⁹ If a Wilmington rental owner does not live in New Castle County, the city requires a property manager who holds both a City of Wilmington and a State of Delaware business license.¹⁵

In unincorporated New Castle County, any owner of a residential property leased for rent must register it with the county; registration is free, and owners must update it by May 1 of each odd-numbered year.²⁰ Since January 1, 2025, New Castle County's Ordinance 23-134 has rental owners give written verification that they meet their Property Maintenance Code duties, including trash and rubbish removal, when they first apply for a rental permit, when they renew it, or when a code official asks.²⁰

EPA's lead renovation rule generally doesn't cover homeowners working on their own pre-1978 homes, but it does apply if you rent out all or part of your home.²¹ Delaware runs its own lead renovation program: firms and workers doing renovation, repair or painting in pre-1978 housing that disturbs more than six square feet of painted surface in a room, more than twenty square feet outside, or that replaces windows or demolishes, must be certified by the Division of Public Health.⁹

Delaware charges a 4.5 percent short-term lodging tax on the rent for a house, apartment or other dwelling rented to guests for no more than 31 consecutive nights, and anyone in the business of offering such rentals to the public needs a Delaware business license.²² Delaware exempts an owner's casual rental arranged directly with the guest when the property is rented for no more than 10 nights in total in a calendar year.²²

In New Castle County, a one-family house may take in no more than three roomers or boarders, the owner must live there, and each must stay at least 45 days.²³ Renting rooms by the night in a county house is a different use from taking in a boarder for a season, so check with the county before listing one.

More than one in four adults 65 and older fall each year.²⁴ A county accessory unit is often built for a parent rather than a tenant. A step-free entry, a curbless shower and wall blocking for grab bars are cheap to include in the first drawings and costly to add later. NAHB's Certified Aging-in-Place Specialist (CAPS) credential trains remodelers in home modifications for aging in place.²⁵

The number on this page reaches one independent company that handles rental conversions in the Wilmington area, and the call is recorded. The design, the schedule and the price are agreed between you and that company.

That company pays us for each call. Connecting costs you nothing, and no one from our side phones or texts you afterward. How we make money

Check the company's state registration before any money changes hands. Delaware's public Contractor Registry lookup lists contractors that properly registered and are considered compliant with Department of Labor laws, searchable by name, ZIP code, certification number, NAICS code or industry; a contractor that drops off the list may not have re-registered, may be under review, or may have been suspended or revoked.²⁶ Contractors working in unincorporated New Castle County must get a New Castle County contractor license, a permit-endorsed license for work that needs a permit, while electrical contractors are licensed by the State; the county's Contractor License Search shows a contractor's license and authorized trades.²⁷ Check a Delaware license

Delaware's Consumer Protection Unit home improvement regulations, effective November 1, 2023, require a written contract listing all material terms, bar asking homeowners to sign incomplete contracts or calling a binding contract an estimate, require a completion date unless clearly disclosed, and bar getting a certificate of completion before the work is done; contractors must give buyers a copy of the unit's summary of the rules before the contract is signed.²⁸ Make zoning approval a condition in the contract, so no deposit goes toward work the city or county hasn't allowed.