Substantive Due Process places limits on government regulation

In planning and zoning, substantive due process is about the substance (topic) of regulation, that the regulation is directly related to its purpose, and is the least amount of regulation to do the job.

When regulating people’s property, one of the major concerns in the United States is that the regulation does not become too much – so that it does not infringe on a person’s private property rights.

There are many ways government regulation may tread on someone’s property rights. Some of those are listed here:

  • The regulation is so much, that it results in “taking” one’s property without just compensation – takings.
  • Failing to follow due process of law – due process.
  • The substance or content of the regulation exceeds what is appropriate subject matter for government to be regulating – substantive due process.
  • Failure to respect and follow the division of authority between the different parts of government – separation of powers.

This article will focus on substantive due process.

Substantive due process has to do with the substance of the regulation, and that the regulation has a logical connection between the governments purpose and the regulation itself, and finally that the regulation is the least amount possible while still achieving the public purpose. Substantive due process is one of our constitutional rights found in the 5th and 14th Amendments, Bill of Rights, of the United States Constitution. The U.S. Supreme Court used substantive due process to give added force to the 4th, 5th and 6th Amendments of the U.S. Constitution.

Substance of the Regulation

Not everything is a legitimate subject for government in the United States to regulate. For example, local government regulation that infringes on constitutional liberties would be out-of-bounds for a local ordinance. Often, one does not see or hear discussion of a topic in terms of “substantive due process.” For example, an ordinance that prohibits a particular race from a neighborhood will get news media attention as discrimination, and a violation of the federal civil rights act. But it is also running-afoul of substantive due process.

Commonly, with zoning ordinances, there are sign regulations. The regulation of signs can be done – as long as it is about placement, size, lighting and so on. But if the regulation is based on what the sign says, that conflicts with people’s free speech (first amendment to the U. S. Constitution) which is a substance of regulation that cannot be done. Thus, regulation of signs must be content-neutral; we do not regulate what the sign says and we do not treat one sign differently than another based on what the sign says. The limitations from the federal or state constitution are not the only limits on government regulatory authority. Through history, court cases have established other areas of liberty which government should not be regulating. Some include personal autonomy, self-dignity, right to privacy, to work, to marry, and more. More on this aspect of substantive due process see the Cornell University Law School’s Legal Information Institute on this subject.

So the regulation has to have a rational government purpose, or in furtherance of a legitimate governmental interest.

Regulation Related to Purpose

The second part of substantive due process is that the regulation relates to the government purpose. In simple terms, that means the local government should be able to explain how the regulation accomplishes its purpose or goal. With zoning, in Michigan, one looks to the master plan to contain the goals, objectives, strategies and actions upon which the zoning ordinance (regulation) is based. Within the master plan there are certain elements, comprising the “zoning plan,” which more directly tie regulation in zoning to goals, objectives, etc. in the master plan.

For example, the zoning ordinance will include a zoning map dividing the municipality into various zoning districts. The zoning plan elements of the Master Plan should clearly show how the master plan developed those particular geographic areas – such as text and existing land use maps and analysis, future land use map, projections showing future housing, commercial and industrial needs, natural resource attributes for working lands and so on.

Another example would be regulations concerning outdoor wood burners. The plan would include information about stack height, requiring use of burners that have EPA efficiently ratings, Phase 2 Qualified boilers and the existence of studies showing how those measures directly address the concerns about smoke from wood-burning units. Where a municipality might run into substantive due process problems is if they just require very large setbacks. The large setback might fail the test that the regulation relates to the government purpose. This is because the government purpose is human health, but large setbacks may not work as studies show unhealthy concentrations of smoke can extend many hundreds of feet from the burning unit, and the buildings or home on the burning unit parcel would still be closer. Thus, the regulation indirectly relates to the intended purpose, and in the case of the house on the same parcel is not receiving equal treatment.

A final example is about rural zoning district’s minimum parcel size. Courts have upheld rural minimum parcel sizes up to about 2½ to 3 acres and minimum parcel sizes over 40 acres. But with very few exceptions has a minimum parcel size of 3 to 39 acres been upheld in Michigan courts. This is because it is difficult to show the rational for 3 to 39 acre parcel requirement. With less than 3 acres one can point to a public purpose of needed space for a drain field, replacement drain field, and such public health concerns. With 40 acre and larger sizes one can point to the public purpose of needing the minimum land area for agricultural or forestry economic viability and similar public welfare concerns. But the 3 to 39 acre parcel size is much larger than needed for public health, and not large enough for the economic public welfare purposes.

So there needs to be a rational connection between what is trying to be accomplished (legitimate governmental purpose) and what the regulation is.

Least Regulation

Finally, the rules should be the least amount of regulation possible to achieve the public purpose. If studies and science shows Phase 2 Qualified boilers will do the job, then that is all that should be required. It would not be appropriate to require stack-cleaning technology that goes way beyond the Phase 2 Qualified boiler design.

Another common example would be with minimum parcel size. In one circuit court case the judge upheld a township’s 40-acre minimum parcel size because given the type soils in that township that much land was needed for a farm or for timber harvest and all this was documented in the township’s master plan. But the judge also recognized that a specialty or niche-type farm might exist on less than 40 acres, so his ruling reduced the regulation to allow less than 40 acres when the public purpose could be accomplished as a result of a niche-farm needing future acres. The result was the 40-acre minimum parcel requirement was upheld except for niche-farms which could have a smaller minimum parcel size.

So the regulation needs to be the least amount of regulation possible to achieve the public purpose.


Substantive due process deals with the substance of the government regulation. Government cannot regulate just anything, it has to be a legitimate government purpose, not contrary to protected constitutional rights and other areas established through our history of court cases. If the regulation is about a legitimate governmental purpose the regulation has to logically be related to that government purpose and not off the mark or indirect. The regulation cannot go overboard, but should be the least intrusive regulation possible while still accomplishing the public purpose.

Professional planners, planning consultants, and an attorney that is experienced in municipal, planning, and zoning law are professionals that understand the pitfalls surrounding substantive due process concerns. Hiring those experts is always a wise strategy for a municipality. Michigan State University Extension has individuals that can help a municipality find the most appropriate professional to contract with. This includes an evaluation of existing zoning and planning to help define a scope of work used in selecting consultants and attorneys. MSUE provides technical assistance to assist with hiring a planner, or conduct a qualifications-based selection process to hire a consulting planner and municipal attorney.

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