Any documentation you may find does not guarantee they are accurate.

@Mark Bischak, Architect Sure, but if the permits specify some facts about the foundation, those are facts that an expert should be able to check for and verify.

I'm not sure what information you are trying to find out. It sounds like there are some old foundations remaining on the property, and the above grade building(s) have been removed. Even if there is a slight chance above zero that the municipal/county records have something on file, especially when agricultural properties are more lax, what would you expect to do with that info that will be insufficient and probably not as built?

A now-performed survey could get you exact placement; a now-performed structural engineer review could determine if they could be reused; a now-performed soils engineer could take borings and compaction tests to tell you about the soil, and the broker should have information on the yield, crops, and irrigation. I'm not sure why you want a geologist to tell you how the earth was formed.

The approximate locations of old foundations can sometimes be inferred from aerial photographs. I believe the service the geologist was proposing was to survey the site using ground-penetrating radar in an effort to identify any remnants of foundations not visible above grade.

Since prior development or construction on the property likely required survey work, the OP may find it productive to check with local surveying/engineering companies to see if they have ever done a survey or development plan for the property of interest or if they have any information on file. In my area, private survey records are often purchased by survey firms from other firms when the principals retire and close up shop.

@3onthetree In this area, the soil compaction is studied by a "geophysical engineer". I called that person a geologist, sorry.

What should I expect to spend for a structural engineer to do a quick assessment of the general location and type of existing foundations?

At this point, I do not own the property and do not want to spend $10K on surveys to determine if I want to make an offer. I am trying to get just simple, basic information about what type of foundations are in place and where are they located. The property is large enough that determining that might require more than just walking the property casually.

@Charles Ross Homes the only survey done on this site was by a local engineering firm that never returns calls. The selling realtor does nothing to provide those survey documents.

You cannot reuse the foundations, so what’s the point? Knowng how much demo and haul away will cost you? Hire an excavating company to give you an estimate for that.

@User I have been told that sometimes you can reuse a foundation. But - assuming that you are correct - it would also be relevant to know the cost to remove all of those foundations.

The "facts" you mention may be fiction. Drawings and specifications submitted with permits show things that do not exist at the time of submission. When the construction occurs, there may be conditions that were unknown before that, but become known at the time of construction, to the extent that the construction varies from what is shown on the construction documents that were submitted with the permit applications.

Sometimes "As-Built" drawings are called for in the project contract, but I rarely have ever see as-built drawings produced.

@Mark Bischak, Architect All of that is understood and there is no substitute at the end for verifying what is in the ground. I am just looking for a process that sets some facts into play that can be verified by a real inspection.

The structural engineer is not one who will help you locate the foundations, but they could help you determine if it can be re-used.

The only thing I can think of that might have this info is a building permit, but not all permits requires a plat to show location of anything either.

Where we live, agricultural buildings are not subject to the building code and are not required to be permitted or inspected. The selling realtor is not doing a very good job of selling if they're not able to provide any information. Whoever built the buildings should have some records.