In inclusionary zoning, developers who build more than a specified number of units must include a certain percentage of units for low- and moderate-income households.20 It differs from the incentive or bonus approach in that the inclusion of low- and moderate-income units is not discretionary. It is the same, however, in that it shifts some of the costs of housing such households to the developer. He or she, in turn, is likely to shift at least some of that cost to the other buyers or renters.
Planned Unit Development
Planned unit development (PUD) has been widely used in the last several decades, and its popularity is still growing. PUD techniques vary, but a prototypical ordinance might work like this. The entire community is zoned in a conventional (Euclidean) manner. However, the law provides that a property owner with a minimum number of acres (say, 20) has the option of applying to develop his or her holdings as a PUD. In this case the property is subject to a different set of controls. The density permitted may or may not be the same as that stipulated by the conventional ordinance, and the uses permitted may or may not be the same. The entire site plan will be reviewed as a single entity under a review process specified by the PUD ordinance.
Some PUDs are entirely residential, and some are entirely commercial. In many cases, however, PUDs contain a greater mix of uses than would be permitted under conventional ordinance. Many PUDs that are predominantly residential contain some retailing. Numerous PUDs contain a mix of residential and commercial uses. Because the entire site plan is reviewed at one time, the benefits of mixing uses can often be had without risking some of the disadvantages. For the urban designer, PUDs can offer vastly more room for creative and innovative design than can be had working under a conventional ordinance.
One problem with many business areas, both downtown and suburban, is that they become almost deserted in the evenings. Mixing residential uses with commercial uses tends to make the area more active in the evenings and on weekends. The mixed-use concept can make both commercial and residential areas more interesting and less sterile. Essentially, the PUD technique places some power to control land use in the hands of a review board or other group, which looks at that particular site design. It allows a degree of innovation and flexibility that cannot be obtained under an ordinance that must fit all cases.
But, like all other techniques, PUD has its disadvantages and its critics. Fort Collins, Colorado stopped using PUDs in the late 1990s for two reasons. One reason was opposition from adjacent property owners. The property owner who bordered a PUD knew in general what would be in the PUD but didn't know specifically what land use would border his or her own property. That uncertainty made property owners uneasy and created an anti-PUD constituency. Municipal officials were also concerned that the development of a large number of PUDs, even if each was well designed, would make it harder to produce a unified plan for the area as a whole.