James Schmitz Jr. stated in black-and-white terms that the cause of decreasing housing affordability is the housing industry's preventing innovators from the "production of homes in factories." ("Homebuilding must modernize," May 2.) He believes that a wide cast of industry players has conspired over the past century to create a monopoly that prevents the efficient building of homes in factories.

This is inaccurate. Most builders currently use factory panelized wall sections. Many are heavily investing in additional off-site technologies that he claims are being excluded from the industry.

Let's discuss in more detail an issue that Schmitz dismisses as a cause of decreasing housing affordability: the cost of regulations.

In recent decades, the country has experienced a trend toward smaller lots and greater neighborhood density. The causes of this long-term trend are complicated.

It was common in the 1950s for city zoning codes to require 80- to 100-foot-wide lots. Land was cheap. Regulations were minimal. Even modestly priced homes could efficiently be placed on such lots. This is no longer true.

One of the most significant causes of this trend is a dramatic and steady increase in development and building costs. For decades, housing costs have risen faster than family incomes, with many negative ramifications, such as a decreased ability to accumulate wealth, increased inequity and reduced job mobility.

There are other causes as well. One is a steady increase in society's expectation for the standard of living. We've also seen the addition of more generous employment benefits in lieu of increased wages.

Meanwhile, the Metropolitan Council's urban growth boundary has artificially constrained the supply of land available for development (land constraints are the greatest future threat to affordability, as seen in many coastal metropolitan areas around the country). State building code revisions have likewise increased housing costs. And we have experienced thousands of small additions to various governmental policies which all add costs to housing. Housing affordability is dying a slow "death by a thousand cuts."

Yet some of the most expensive regulations would likely be viewed by the public as valuable and worth the high cost:

• Stormwater: Since the early to mid-1980s, we have learned a great deal about how to minimize flooding and protect the water quality of lakes and rivers. Dealing with stormwater now uses up 5% to 15% of land in a new neighborhood.

• Wetlands: The Wetland Conservation Act resulted in the protection of this valuable resource, but it has certainly removed a great deal of developable land from our neighborhoods, increasing costs.

• Energy efficiency: Another expensive regulation was implemented statewide in 2015. This legislation dramatically increased the energy efficiency of new homes.

Combined, just these three regulations, while producing a positive impact on the environment, have significantly increased the cost of homebuilding.

There are also many regulations and processes that do not deliver value, such as requiring stone on the fronts of starter homes, having five or six wetland experts meet on site to verify that wetland boundaries are correct, navigating through duplicative stormwater reviews from both cities and watershed districts, completing Environmental Assessment Worksheets for modest size neighborhoods, and thousands of other regulations where cost has never been considered.

It is time to have an open discussion about how to alter regulations that have accumulated over the past 70 years to make homes affordable to more people while still meeting the goals of the various regulators.

In response to these additional home costs, home buyers have decided that they would prefer to sacrifice yard space instead of home space. Builders across the country have responded by creating smaller lots. Zoning codes are being revised to reflect these market realities.

Decreasing lot sizes and reduced affordability is not a trend most of us like to see. This is a complex and urgent issue. Let's focus on improving the current situation.

Paul Heuer, of Chaska, is a developer and former city engineer.