MADISON, Wis. -- State environmental officials want to make the first major changes in shoreline building rules in more than four decades.

Their plan calls for limiting shoreline structures' height to 35 feet. The size of impervious surfaces, such as roofs and pavement, would be capped at 30 percent of the lot.

Owners of existing homes would no longer need county variances to make improvements if they plan to spend more than 50 percent of the property's value.

The state's shoreline rules were created in 1968. State officials said development in northern Wisconsin is growing more intense and water bodies must be protectedd.

The Natural Resources Board is expected to vote on the revisions at a June 24 meeting.