If Butler were a mosaic, its rental housing picture would be missing a piece or two.

There are between 1,500 and 2,000 rental homes within the city, most of which are well maintained. But others are not. Not surprisingly, most of the substandard units are of the low-rent variety. They tend to come with deficiencies that violate the city’s building codes — everything from gas and water leaks to moldy walls and broken windows. There are also health code violations: roaches and bedbug infestation — things no renter should have to endure.

Some serious violations force the temporary eviction of tenants until repairs are made. Code enforcement officer John Evans says this happens with regularity, about once every other month.

For an unscrupulous or absentee landlord, this might be business as usual. But for tenants it’s a harrowing experience. Already forced to tie up scarce money on a security deposit, they might be forced to come up with another deposit for a temporary unit, if they can find one that’s available on a week-to-week or month-to-month basis, while waiting to move back into their home. It’s more likely they’ll move in with friends or relatives until the fixes are made. It’s a gargantuan inconvenience, to say the least. It’s a threat of homelessness if you want to say more.

Evans says the city gladly will inspect apartments for prospective tenants. There’s only one problem: tenants must sign a lease before they can invite an inspector onto the property without the landlord’s permission.

Tenants also can file a formal complaint if a landlord fails to fix problems — but they risk a temporary eviction, a realization that likely deters some from taking action.

This is the missing piece, one that is easily replaced. The city council could enact an ordinance requiring annual inspections of rental properties to ensure there are no code violations.

Already this year it adopted annual fire inspections for commercial buildings, which include residential apartment complexes with more than two units. But those inspections check only for fire hazards — wiring, smoke detectors and sprinkler systems.

Many landlords already submit to annual inspections, including those participating in the federal Section 8 housing program. Administered by the Department of Housing and Urban Development through the Housing Authority of Butler County, the program pays rent subsidies for low-income individuals and families. If a violation is found during inspection, the landlord is required to fix it.

The city already can and does fine landlords for violations. The potential for fines would motivate more landlords under the certainty of regular inspections.

Rental housing, even the lowest end of the low-rent housing, should be clean, decent and safe. Many Butler landlords meet this minimum standard. Others apparently could use a little prodding, in the form of annual inspections of their properties.