Its Not a Problem

Interim Control Ordinances (ICO)
This is the term used to help a municipality figure out what to do about the GAP issue.

The gap issue is the difference between older zoning ordinances that worked to maintain equitable rights in their communities and the change in the way real estate occurs now, a trend that was developed to take advantage of this gap.

This from Guide to Community Planning in Wisconsin by Brian W. Ohm

2.4 Interim Control Ordinances

Starting a planning process often raises the need for communities to suspend new development for a brief period of time while studies are completed and plans and ordinances are prepared or revised. A temporary moratorium is a technique that can be used to provide this needed "time-out."

A temporary moratorium, also known as an interim control ordinance, can be an important planning tool. Many communities throughout Wisconsin have imposed moratoria on new development as they engage in planning processes to address issues of growth and change. These moratoria have taken various forms, including moratoria on rezonings, building permits, and subdivision plats.

Quoting Mary Norwood from Atlanta when they took action:

“The legislation clarifies and closes many loopholes in the 1982 zoning ordinance.

The desirability of city living in Atlanta has led to the remodeling and redevelopment of many existing residential structures as well as the purchase structures for demolition in order to re-use the lot for a new building. With the preservation of neighborhoods as a high priority for both the City Council and the Administration, this new legislation can help protect the quality of life for all city citizens.

This legislation will allow our residents to continue to build and renovate to today's lifestyle preferences, and it provides some degree of oversight for appropriate and orderly development."

In Atlanta, there was first a moratorium while the Mayor's Infill Task Force began, and then Interim Standards, and then neighborhood input, and then professional study and recommendations, and then community feedback, final negotiated changes, and then acceptance by ALL affected parties.

Google this to see how prevalent the problem is and what others are doing about it.