A residential pool starts operating like a commercial facility when paying guests begin showing up each week.

That reality sits at the center of a Minnesota court ruling involving Swimply, the online platform that allows homeowners to rent their pools by the hour.

In April, the Minnesota Court of Appeals ruled that homeowners who rent their pools through the Swimply platform can be required to comply with public-pool regulations because their pools fall within the state's definition of a public pool. The decision is one of the first major appellate court rulings to directly address the growing practice of homeowners renting private pools to strangers by the hour.

Swimply, often described as the “Airbnb for pools,” allows homeowners to rent pools, hot tubs, and other recreational spaces to the public. The company reports more than 15,000 hosts and millions of bookings nationwide.

The case arose after the Minnesota Department of Health in 2021 determined that homeowners renting pools through sharing-economy platforms could be subject to publicpool regulations. Homeowners challenged that interpretation, but the Court of Appeals sided with the state.

Under Minnesota law, public pools must be licensed and routinely inspected. The state's definition includes pools that are open to the public generally, whether for a fee or free of charge. The Department of Health argued that once homeowners advertise pool access to members of the public through an online platform, they move outside the traditional exemption for private residential pools.

In explaining its position, the department stated, “Because you are advertising this pool for use by the public, we would not consider it a true private residential pool.”

Doug Seaton, president of the Upper Midwest Law Center, which represented homeowners challenging the policy, said, “We respectfully disagree with the court's decision. This case is about whether a state agency can create and enforce new rules without going through the process the law requires.”

For service companies, the ruling highlights a growing gray area within the industry. Thousands of pools nationwide were designed and maintained as private residential pools, yet some are used in a way that resembles commercial facilities.

Many service agreements are written for residential pools with predictable bather loads. But a pool that begins hosting paying guests may require more chemicals, more frequent maintenance, and earlier equipment replacement. In some cases, service companies may not even be aware that a customer is operating a short-term rental business. That raises practical questions: Should Swimply pools be serviced differently than typical residential pools? Should contracts, pricing, and insurance coverage reflect the increased usage?

The litigation also highlighted concerns about the costs of complying with public-pool regulations. Public pools in Minnesota are subject to licensing, inspections, waterquality standards, and various safety and recordkeeping requirements. Opponents argued that some homeowners could face significant costs to bring existing backyard pools into compliance.

Whether other states follow Minnesota is unclear. Pool regulations vary considerably from one jurisdiction to another, but Minnesota is not alone in scrutinizing pool-sharing platforms. Regulators in states including New York, New Jersey, California, and Arizona have considered whether rented residential pools should be regulated as public facilities.

The broader issue is whether regulators focus on how a pool is built or how it is used. Two identical backyard pools could have the same bather load and require the same level of maintenance, yet one might be considered private while the other is classified as public simply because money changes hands.

Minnesota may be the first state to draw a legal line between a private backyard pool and a pool-based business. As pool-sharing platforms grow, service companies in other states may find themselves navigating the same waters.