The highest courts in five states have either ruled on strict enforcement of minimum housing standards or have such action pending, according to the National Association of Housing and Redevelopment Officials.

The association says that in the past lower courts often ruled on the validity of local housing laws that require property owners to meet certain minimum standards for toilet and other plumbing facilities, heat, ventilation, fire protection, occupancy, and the like. But until recently such cases had not been pushed to the courts of last resort.

According to the association, the reason for this new insistence on getting final rulings is that more and more cities are stressing slum prevention and making it harder for property owners who fail to comply with the standards for health, sanitation, and safety.

Cities have been encouraged to insist on certain dwelling; standards because only those who can show they are developing housing codes are eligible for federal aid under the urban renewal program, the association says.

The strict enforcement of housing laws means in many instances that if a property owner is not willing to put out the money for repair of neglected buildings, he must tear them down.

This new drive to bring substandard housing back into condition thus has made a number of property owners unwilling to take anything but the "last word"—that of the states' highest courts— about whether they must comply with a city's orders enforcing its housing laws.

Decisions by the top courts in Arkansas, Maryland, and South Carolina upheld local housing

laws setting minimum standards. Pennsylvania's supreme court has been asked to pass on Philadelphia's housing code. The Wisconsin supreme court negated bath-sharing controls in Milwaukee's old housing code but did not rule on the question of constitutionality.

A sixth test will be on the record if opponents of the new housing code in Denver, Colo., carry out their threat to bring to the state's supreme court their contention that the code is unconstitutional because it allows the taking of substandard property without compensating the owner for the loss.