Equivalent Dwelling Units (EDUs) – A Mirage of a Nexus

I recently came across a few DIF calculation studies where the impact fees were calculated upon the concept of an Equivalent Dwelling Unit (or EDU, not to be confused with ADU’s or Accessory Dwelling Unit). In this method, one land use, in this case, detached (single family) dwellings, is used as a baseline for demand, and then that baseline “number” is transferred to all other land uses such as commercial and industrial uses as well as commercial lodging, and attached dwelling units.  The studies claim the following:  

This approach establishes, for given land uses, a method of comparison of that land use to a baseline land use, utilizing a common demand variable.

Equivalent Dwelling Unit Model. Future Demand is based upon a per capita EDU basis with a “baseline” fee that assumes that every resident, business customer, or employee within the City has an equal basis in generating a police or fire call-for-service. As an example, in law enforcement and fire/paramedic services, the common EDU variable is people.  So, the argument goes that a 200,000 SF industrial building with, say, 50 employees will generate the same amount of law enforcement or fire/medic calls-for-service as 20 apartment units with an average of two and a half persons per unit (or, again, 50 people).  The same could be said for the fifty persons in a 25-unit hotel with two persons per keyed unit.  Amazing how that works out. But the use of “persons” as a standard for all police and fire/medic calls is nonsense and does not reflect reality. Every land use has its own unique police or fire call generation ratio based on actual data, independent of any other land use and the various public agencies have that data available.  “Persons” do create demands for service, but the land-use they are in when they need those services varies. This is sheer folly at best and a possible violation of Government Code Section 66000 et seq. at worst. 

To continue, an additional example would be to say that the police and fire calls-for-service volume for four detached dwelling units with an average of 2.5 persons each (10) would be the same as an insurance office with 10 employees.  Simple logic and reason will tell you otherwise (or just ask a police officer or fire fighter if this argument makes any sense!). Past RCS studies have identified that each basic land-use (in each agency) has a unique and different individual demand use.  No one land use qualifies as a baseline land use, nor does it need to.

This can be made far more accurate because there is very valid information available within that public agency to identify how many times (within a year) that the police or fire staff responded to all of the industrial use structures in the past year. The City also has the records to be able to estimate how many square feet of industrial building space that currently exists in the City.

City Land-Use Data-Driven Model. A more accurate method of determining the differing demands on public safety services is to simply divide the number of calls-for-service that the police and fire departments responded to, as an example, industrial uses by the number of square feet of industrial buildings, and you can determine the demand rate for fire calls for, say, per 1,000 square feet of industrial space.  Do this for all land-use DIF categories that the public agency has or desires and you will find that each of the City’s basic land-uses, i.e. detached dwellings (AKA single family), attached dwellings (AKA multiple family), hotel/motel, commercial business uses, and industrial uses demand ratios and you will find how that each land-use differs greatly from any “baseline” land-use.

RCS will acquire the City’s current land-use database of existing and future development from the planning or community development department.  RCS will then work with the police and fire departments to acquire the log of calls-for-service for the past 12 months.  As stated before, they are based upon actual statistics from and applicable to only that client.  Following is the average of police and fire CSFs (Calls-for-service) collected from over twenty public agencies which indicates nothing can have an equivalency to a detached dwelling unit.

Land Use	Police CSF	Fire CSF
Detached Dwellings	0.907/Unit	0.143/Unit
Attached Dwellings	0.864/Unit	0.096/Unit
Manufactured Homes (on pads)	0.564/Unit	0.149/Unit
Hotel/Motel Rooms	0.328/Room	0.069/Room
Retail Uses	0.876/KSF	0.038/KSF
Office Uses	0.135/KSF	0.015/KSF
Industrial Uses	0.087/KSF	0.009/KSF

 So let’s recap: using the Equivalent Dwelling Unit method would state that an equally sized retail and office space would generate the same police demand, while RCS data shows that a retail business will generate nearly 6.5 times the actual police calls-for-service (0.876 ÷ 0.135 = 644%as would an equally sized office space.  For Fire calls-for-service, the delta is closer but still a statistically significant difference at about 250 percent higher for retail versus office uses (0.038 ÷ 0.015 = 253%).

Why is this important?  Government Code Section 66000 et. seq. requires that impact fees recognize differences in impact between land-uses.  The EDU method assumes that any person in any land-use environment has the same likelihood of requiring a public safety call-for-service.  That assumption is simply false.  It is the nature of the land-use that creates the differences in demand, not the number of people there. 

Which set of impact fees would you rather go to court with, the EDU method or the City Land-Use Data-Driven Model.? Or, more importantly, which set of DIFs would you like to have to protect your public agency from legal challenges?

If you receive a proposal, be sure to determine if that consultant is proposing to take the easy way out with a simple “equivalency” model.  Certainly it is easier and quicker, but you deserve better, you need better.