County explains soil test requirement for homes6 min read

Building a new home in unincorporated Yavapai County comes with a cost many aren’t aware of when they begin planning: A geotechnical engineering report.

The report is mandated by Yavapai County and can range from around $1,000 to $3,000. Factors such as site topography, travel distance and more affect the cost. Wait time for results to be returned also varies, but can be six weeks, depending on demand.

The report is required upon seeking a permit for a habitable residential structure. The test samples soil to see if expansive or other negative factors will not allow foundations to be set in a specific location. According to Mark Rogers, chief building official for Yavapai County, these types of soils are common in the area.

“It’s mainly for new single-family residences,” Rogers said. He added that habitable structures over 400 square feet are also subject to the requirement.

A waiver can be given in instances of solid rock foundations, Rogers said, but added that it has only happened once in his tenure. There are other inspections still needed, however.

The county does not have a fee associated with the tests, which are done through third party state-licensed engineers hired by the homeowner. The county provides an incomplete list based on past experiences with companies, but does not endorse any of them.

Mandate Reasoning

Advertisement

The mandate came about in 2015 because “We had too many homes being built to substandard footings that within a few years were settling to the point of costing the homeowner and or subsequent buyer major problems,” according to Yavapai County District 2 Supervisor Thomas Thurman.

District 3 County Supervisor Randy Garrison said he had received complaints over the requirement and its costs, mainly in the Village of Oak Creek, when he was running for the county seat.

Garrison said that former District 3 Supervisor Chip Davis and other county staff explained to him that the requirement came about due to many instances of building on clay. He said one of the developers primarily responsible for the Verde Villages property south of Cottonwood as well as property over the mountain in Prescott Valley had begun to separate from the foundation. Resulting lawsuits also led to the decline of the company, according to Garrison.

Thurman said the requirement had been unpopular, but that many saw the need for it in the area. He said residents have benefited from homes that will remain solid for many years, but said that any substantial metric to point to would take many years to accumulate.

“But I can tell you we have had too many problems in the past that shows us we needed this,” he said.

“When you ran up enough counts in an area that said you have a problem, then you have to recognize and address that problem,” Garrison said, adding it would be maleficence to not create the mandate.

“There were a lot of people that were very supportive,” Rogers said of the requirement. “They way we look at it, you’re spending a lot of money on a new home. With all the problems we’ve had over the years … this was to help the contractor and the homeowner.”

Rogers said the initial sticker shock of the report was apparent in some, but it is basically “cheap insurance” for a solid foundation. Now that the requirement has been in place for a while, he said many have taken it as part of the normal set of rules.

In terms of engineer manpower, Thurman said he thinks there are enough today, but depending on the demand, that is not always the case. There has been no discussion into any subsidy from the county to homeowners to obtain the reports.

Rogers said the county has not had to add staff or hours to deal with the reports.

“It actually makes it easier because it’s easier to go to the soil report” and make sure all plans and reports line up, Rogers said.

Liability

Should something go wrong — a foundation crack or similar damage — despite a soil test coming back giving the all clear — Rogers said liability could fall on the engineer.

Whoever designed the house based on the report could also be held responsible. The report includes recommendations for foundation design.

“He [the geotech. engineer] is only responsible for his part,” Rogers said. “Most of the reports we see here are good reports.”

“If something fails, the fingers are going to be pointed at a ton of people, the county included, because the building department approved the plans,” Garrison said. “What you’re trying to do [with the report] is you’re trying to protect the builder and not only the owner but the future buyer as well.

“It’s a significant investment people are putting into that home and you want to do everything you can to help them protect themselves and those future owners. So, unfortunately, that comes with a cost.”

Not Just Homes

According to Garrison, the county must accept the costs of area soil, too.

“We recently just finished paving Saddlehorn in the Village of Oak Creek,” he said. “It was a little over a halfa-million dollar job.”

However, due to a wet winter, the clay soil became unworkable and $270,000 had to be added to the cost to add concrete and amend the soil. The geotechnical engineering report was part of that process.

“Homeowners are having to get engineers, we’re having to get engineers. These are situations we aren’t really trained to deal with,” he said.

Garrison said he would like to spend county money on new roads as opposed to testing on the public level, but that the risk is too high to not perform the tests.

Incorporated Requirements

Those who live in incorporated towns face looser requirements, in general.

Robert Foreman, with the building department at the Town of Camp Verde, said the town requires a soil classification test and based on those results, can require the geotechnical engineering report.

In Sedona, City Engineer Andy Dickey said, “For residential development typically this analysis may be required when soils are steep on a site, when there is non-native — imported — soil, or where we have reason to believe that there are unsuitable soils. “Other than these instances, the codes specify minimum design requirements, which are typically met and exceeded by building design applications here at the City of Sedona.”

In Cottonwood, as a general rule, the city does not require a geotechnical engineering report for every new residential structure within its jurisdiction, according to city Engineer Robert Winiecke.

“However, there are certain areas within the city’s limits that are known to have in-situ soils that may be unsuitable for building upon. In these cases, the city does require that a geotechnical report be prepared by an Arizona licensed professional engineer and submitted to the city for review and acceptance as a condition of the building permit,” he said.

Andrew Pardiac

A 2008 graduate of Michigan State University, Andrew Pardiac was a Larson Newspapers' copy editor and reporter from October 2013 to October 2017. After moving to Michigan, then California, Pardiac was managing editor of Sonoma West Publishers' four newspapers in Napa and Sonoma valleys until November 2019.

- Advertisement -
A 2008 graduate of Michigan State University, Andrew Pardiac was a Larson Newspapers' copy editor and reporter from October 2013 to October 2017. After moving to Michigan, then California, Pardiac was managing editor of Sonoma West Publishers' four newspapers in Napa and Sonoma valleys until November 2019.