Metro Councilmembers will on Tuesday vote for the third time on a proposal to allow outbuildings on residential properties placed under an overlay.
Known as a detached accessory dwelling unit, an outbuilding is a secondary, typically smaller, building on the same property as a primary building. On a residential lot, an outbuilding is often referred to in the southwestern United States as a casita and in some countries as ‘granny flats.’ Property owners most commonly avail themselves of these constructs for office space, storage, studio space or additional housing — the latter a use that has become much more popular as residential real estate has risen in price in cities across the country.
A feasibility study by the Nashville Civic Design Center has informed the Metro Council ordinance that creates an overlay zone for them. The study lists the so-called DADU ordinance among several considerations for outbuilding construction, including environmental sustainability and the building design’s impact on occupant health. It proposes amendments to municipal code to make an overlay zone in which outbuildings can be constructed.
An overlay zone superimposes a set of standards onto an area’s existing zoning rules, ideally without contradiction. The Metro proposal — which has received two affirmative votes and is being co-sponsored by Councilmembers Burkley Allen, Sean Parker, Ginny Welsch, Freddie O’Connell, Brett Withers, Brandon Taylor, Emily Benedict and Zulfat Suara — addresses “many homeowners” in single-family units, including long-term rentals, who have requested the option for detached units. Backers are positioning the proposal as one way to help reduce the incentives for some property owners to demolish existing homes and replace them with two full-size homes on a single lot.
If passed, the ordinance will take effect on May 24 for single-family units in low-to-medium-density zones.
The Civic Design Center study addresses the outbuilding’s distances from the property line and the primary building, as well as various ways properties with these buildings can be planned. It also accounts for easements such as sidewalks and utility installations.
The study shows that DADU feasibility is partly dependent on lot accessibility. It covers four options: corner lots and interior lots, each with or without alleys. Each lot type is assessed for accessibility. Lots with alleys, it maintains, provide the opportunities for back-of-lot vehicle access, for example, but not without expanding setbacks that would likely eat into property space.
Metro Codes do not allow new outbuildings to obstruct alley access to the primary structure. Most likely, the Civic Design Center found that Codes would require new vehicle access to outbuildings on corner lots to be via an alley and not side streets. Properties with alleys would need outbuildings with 18-foot setbacks from their alleys to accommodate parked cars unless external parking was built into the outbuilding.
Council’s pending vote on DADUs comes on the heels of the establishment by Mayor John Cooper of the Landlord Risk Mitigation Fund, which Cooper’s office describes as a public-private partnership intended to ensure more Nashville families are housed. The fund is to provide landlords an extra $1,000 from United Way of Greater Nashville, donated by The Frist Foundation, for every housing choice voucher they accept from the federal government, whether for subsidized or private-market housing. Extra dollars are to cover damages or rent in arrears.
Renters in neighborhoods referenced in the text of the DADU ordinance would benefit from this for missed rent payments or coverage for damages — even to detached accessory dwelling — if they are enrolled in the federal Housing Choice Voucher Program for private-market housing. So far, the Metro Development and Housing Agency and the Homelessness Impact Division have secured housing for about 350 people via the Landlord Risk Mitigation Fund.