The Historic Structure Policy Review Committee got it right when it made the ordinance voluntary instead of mandatory, even with respect to "local landmarks."
First, exactly which privately owned structures are these "local landmarks?" So far, that phrase has only been subjective. Why not start with identifying exactly which privately owned properties are considered "local landmarks?"
The next goal would be to do what is necessary to preserve these structures. What is the best and most equitable method to do this? Simply put, what we are talking about is that the public would like to control or own the development rights for these landmark properties. That way the owner of the property would be restricted with respect to any changes or redevelopment of the landmark property.
This exact same problem has been successfully handled in the county, where the public sought preservation of certain ranches. The answer was the creation of the Purchase of Development Rights program (PDR). Through a process, the owner separates off the development rights in exchange for consideration (money) and tax breaks and benefits. Thus, there is no "taking" of a person's private property interests without just compensation (a historic principle that we also seek to preserve).
Here, the solution to balancing the desire of the public to preserve certain buildings and the legally protected rights and interests of the individual property owner, is easy.
1. Identify exactly which properties are to be considered "local landmarks."
2. Identify which properties are privately owned and which are publicly owned.
3. Set up negotiations with the individual property owners to identify a fair market value for the development rights on each property. (Failure of owner to cooperate still leaves city with eminent domain rights.)
4. Set up a funding mechanism like the PDR program and set up some tax breaks/benefits to purchase those rights and easements.
The process has worked great for our county lands. It also would work well, and justly, as we seek to preserve our historic buildings and our heritage of American Values as well. To take these development rights from the owners without compensation is just plain stealing, whether under the guise of an ordinance or otherwise. To acknowledge up front that what the public is asking to receive from these owners is actually an interest in real property with separate and distinct value, is honest.