Many landlords – both residential and commercial – have been trying to set themselves apart and attract more tenants by allowing pets.

It’s true that pets can cause damage to a building, but it’s also true that there’s a growing demand for pet-friendly environments, and allowing pets can make a rental property much more attractive.

Some 17 percent of businesses across the U.S. now allow pets at work, according to one recent survey. Most of these are small businesses and traditional stores – such as a bookstore with a cat – but many large companies such as Google and Apple now allow pets in offices, and other businesses are following suit.

If you’re a landlord (or a tenant) and you want to have a pet policy, it’s best to spell things out in the lease. For instance, the lease might specify what types of animals are allowed, and require that all pets be healthy, vaccinated, housebroken and well-socialized. A lease might also require that pets be kept on a leash in any common areas. A landlord might want to set aside certain common areas as pet-free zones.

Both landlords and tenants will want to make sure that their insurance policies cover dog bites.

Landlords might want the lease to specify that the tenant will be responsible for any damage caused by a pet. They might also want to insist on a larger security deposit from tenants with pets.

Although both children and pets can cause damage to an apartment, it’s against the law for a landlord to ask for a larger security deposit from tenants with children – because this would be discrimination based on family status, which is prohibited by the federal Fair Housing Act. However, there’s no law against asking for a larger security deposit from tenants with pets.