Zoning Practice — June 2006

Ask the Author

Here are reader questions answered by Gail Easley, FAICP, author of the May 2006 Zoning Practice article "Conditional Uses: Using Discretion, Hoping for Certainty."

Questions from Sandeep Aysola, Wilbur Smith Associates:

I am working on a study for a very large university medical center located in the city of Newark, New Jersey. I am trying to come up with off-street parking generation rates for different facilities proposed in the vicinity of the university medical center. I'd appreciate if someone can guide me on coming up with some general guidelines for computing parking generation rates. I've noticed that the ITE manual on parking generation doesn't have a whole lot — especially on the types of land use I am trying to generate spaces for.

Answers from author Gail Easley:

Q1. Auditorium with 400 spaces — I used land use live theater #441 (rural) with 0.25 spaces per seat to come up with 100 spaces.

A1: I think one parking space per four seats is too few unless you have a situation where most users arrive other than private car. One parking space per three seats is more common. If the auditorium has any other facilities, be sure to calculate the parking for the other uses separately.

Q2. Cancer center 214,000 SF; 23,000 per floor — I tried coming up with parking spaces based on Nursing Home #620 (223 spaces) and Clinic #630 (948 spaces). I'd like to know which one of the two is more representative of a cancer center facility.

A2. The primary question to ask is whether the facility is outpatient (clinic) or overnight (nursing home). I suspect that the clinic rate will be more appropriate.

Q3. 234 apartments housing 465 people- I used land use #222 High rise apartment with 1.37 vehicles per dwelling: about 321 spaces.

A3: This is a reasonable fit, although a slightly higher rate will ensure parking for multiple vehicles per unit and visitors.

Q4. 13,000 square feet of retail — #815 free-standing discount (non-December peak) — 2.75 vehicles per 1,000 square feet, which gives me 36 spaces.

A4. This is probably low. I think a more typical rate would be 3 to 4 spaces per 1000 s.f.

Q5. 350,000-square-foot neuroscience facility — There isn't much on a medical research facility. So I used the land use code #701 Office Building to get 840 spaces.

A5. This facility would be most closely compared to a research park, office park, or research laboratory. I found several standards for these uses in Planning Advisory Service Report 510/511. I recommend that you obtain and use this report for your work. The range of standards for a research park resulted in a similar number of spaces up to as many as 1,400 spaces.

Because this is a university facility, it may be more helpful to query other similar facilities for their parking standards and an answer to the question: Does the standard result in enough parking? Also consider whether most users will travel to the facilities by private car or transit or other means. Are the facilities located to take advantage of any shared parking spaces? Shared makes sense when the peak demand periods differ for each use. The PAS Report provides assistance on this topic as well.

Question from Linda Donnelly, Village of Spring Green, Wisconsin:
How can the conditional use process be used to limit development along a major highway to highway-serving uses? This limitation is necessary to implement a provision in the plan that seeks to protect the downtown economy by prohibiting uses on the highway that would draw activity away from downtown.

Answer from author Gail Easley:

I don't think the conditional use process is the most appropriate means to implement this provision of the plan. The conditional use process is based on the underlying assumption that the proposed use can be appropriate if conditions (design and other standards) are applied, primarily to ensure compatibility and mitigation of potential impacts. In your situation, the issue is not making the use compatible, but prohibiting unacceptable uses. Therefore, the land use or zoning regulations should very clearly describe permissible uses that are consistent with the plan provision and should not provide that other, unacceptable uses might be allowed through the conditional use process. This means that there should be a specific list of uses that may be allowed through the conditional use process and that the list of potential conditional uses must also be consistent with the plan provision. You need clear and specific uses identified and not an open-ended description of conditional uses, such as "other uses as approved through the conditional use process."

It is difficult to implement a standard that requires a use to be "highway-serving" or "highway-oriented" unless you define the use as one that specifically serves travelers, such as gas and service stations, transient lodging, and so on. I do not recommend this type of standard as part of a conditional use process. Rather, the approach to ensuring the viability of the downtown and the limitation on conflicting uses on the highway is threefold:

  1. a clear and specific provision in the plan;
  2. a clear and detailed list of appropriate uses permissible for the highway commercial area;
  3. a clear and detailed list of appropriate conditional uses for that same area.

Further, if you do not have separate land use or zoning districts for the downtown and highway, consider adopting an additional district in the regulations or applying an overlay district to the highway. That is, if you have one commercial category that applies to both situations, you will have a continuing problem unless you add something to the highway area, such as an overlay or a separate district. Finally, be sure that your regulations include language that prohibits uses that are not specifically permissible either by-right or through the conditional use process.

Question from Mark Ostgarden AICP, City Planner, Brainerd, Minnesota:

What are the potential consequences of allowing a home occupation in a detached accessory building in a residential district through the conditional use process?

Answer from author Gail Easley:

First we should consider the basis for home occupations and the basis for conditional uses. For those jurisdictions with exclusive residential districts, the idea is separation of residential uses and commercial or other nonresidential uses. However, even with the idea of separation, most local governments recognize that there are some nonresidential uses that are desirable. These nonresidential uses occur in two ways: home occupations, which create the opportunity to conduct a business in the home when the conduct of that business meets certain requirements to ensure the protection of the residential character of the district. The second situation typically applies to uses on separate lots, such as churches, schools, day care centers, community centers, or other uses that have been determined to be acceptable when conditions are assigned to mitigate potential negative impacts.

Across the country the types of businesses that are allowable as home occupations varies greatly. I know of some areas where the only business is a home office and others where a veterinary clinic is considered a home occupation. Local custom and the willingness of the citizens to accept the introduction of more nonresidential uses are essential when considering the expansion of the types and extent of home occupations. In jurisdictions where home occupations are not allowable in accessory structures, this requirement serves to limit the potential impacts. The assumption is that people will not want activities within their homes that have fumes, odors, or require significant storage, for example. However, the idea of mixed use neighborhoods and traditional neighborhood development welcomes cottage industry.

Some jurisdictions also allow different types of home occupations in different districts. For example, it is relatively common to limit home occupations to the principle structure in more dense residential neighborhoods but to allow home occupations in accessory structures in estate and agricultural residential districts.

Whichever approach you take, the important feature is the consideration of the types of impacts from various uses — considering electronic interference, odors, fumes, and noise from operations. Be sure that the standards (conditions) are enforceable. For example, how and where would you measure odor to ensure that there is no negative impact to neighbors? It is often easier, in the home occupation situation, to limit the types of uses to those not likely to have the negative impact at all because enforcement is so difficult.

Finally, I see no reason that you could not craft a regulation that allows certain types of home occupations as conditional uses in detached buildings, provided that you have a clear and specific list accompanied by an identification of the categories of conditions that will be considered for imposition if the use is approved. The more a property owner knows about expectations of the local government, the better. Be sure to consider impacts such as noise, hours of operation, parking if the use will have customers at the site, traffic, trucks and deliveries, lights, odor, electronic interference, and the ability of the business to expand. Assume someone is making and selling a product. What happens when the business is successful and needs more space? The more situations you can identify in advance, the better you will be able to include provisions in the ordinance.

Question from Stan Boling, Planning Director, Indian River County:

How much discretion can an approving body have over conditional uses?

Answer from author Gail Easley:

Your ordinance or regulations should clearly establish the ability of the approving body to require conditions in addition to the conditions that may be specified in the regulations. Since there is no specific state requirement to apply in your jurisdiction, you have considerable latitude to adopt regulations that are specific (as you mentioned, location, setback, and so on) but also to include a statement that additional conditions may be required to ensure that the impacts of the proposed use do not result in an undue negative impact on the surrounding area. Be sure that you have such "enabling" language in your regulations. However, as I pointed out in the article, too much discretion can result in treating substantially similar situations very differently. Therefore, I recommend as much specificity as possible in the regulations while still allowing the imposition of "other conditions as necessary to mitigate potential negative impacts." You want to be sure that your procedures require written findings to support the decision. This will ensure that there is a relationship between the potential negative impact and the discretionary conditions.

Question from Stan Boling, Planning Director, Indian River County:

How closely is discretion tied to specific use criteria?

Answer from author Gail Easley:

Again, this is a matter to address within the regulations. I think you could have an overall statement about the ability of the governing body to impose conditions beyond those enumerated — either by type or by specific standard, so long as such conditions are tied to a potential impact. Make sure you have written findings in your record to support the imposition of conditions.


Is there a difference in the degree of discretion between administrative permits, approved by the planning commission, and conditional uses, approved by the elected body?

Answer from author Gail Easley:

The important feature is the limitation specified in the regulations. There is no reason the planning commission could not have discretion to impose different standards. However, the ability to exercise discretion should be spelled out; conversely, if there should be strict compliance with a set of standards and no discretion, that, too, should be spelled out.

Question from Bjorn Hansen, Transportation Program Coordinator, Centralina Council of Governments:

What is the best way to address school site selection as a conditional use?

Answer from author Gail Easley:

The first thing to consider is the types of impacts that may occur when a school is located in a given zoning district. In your situation, schools are potentially permissible in any zoning district. Clearly, the potential impacts from the school will be very different when locating in a residential area than when locating in an office area. On the other hand, the impacts are not all from the school to the surrounding area. Locating a school in an industrial area, for example, probably requires standards to ensure adequate protection from truck traffic or other features of the industrial development.

This means that the conditional use criteria will vary from one zoning district to another and will not be "universal" for schools wherever they may locate.

Once you have a list of impacts, you should also identify the unique design requirements for schools — for example, bus lanes and access separate from the parking area as well as drop-off/pick-up lanes for students being transported in private vehicles. Safety requirements for modern schools often require specific fencing, lighting, and limited access. The ways the features are incorporated into the neighborhood must be addressed.

With the lists of potential impacts and special design features, you can then consider the standards that will be acceptable for the zoning districts where the schools will be permissible. The local school board should be involved in these discussions, because the standards will affect their land needs and design costs. The board should also be able to see that your regulations are considering the unique needs of the school and not just the impacts from the school on the neighborhood.