A: Built in the 1920s? Ahh, one of the charms of property in the Grand Valley - much of it was developed long before there was zoning, building code inspections and other regulation. And, there are so many different jurisdictions for those regulations; what applies on one side of the street may not apply 100 feet away on the other side.You did not mention specifically what you want to research so I will see if I can give you an overview of one or two resources to get you started. Then, as you visit or call each resource, ask them who else or what other office, business or agency you might want to pursue information from.For starters, the Mesa County Planning Department is probably your best bet as a general resource. You can learn a lot from their website and even more by going down to the office at 200 S. Spruce St. and talking to one of their staff.You will want to know the zoning. You mentioned there is a single family house on the property but you might want to know if that is the highest or only use for the property.On a property I looked at recently, there was a single family house and the zoning on the MLS listing paperwork seemed to indicate that was the only thing that could be built there. However, there was a mix of uses within sight of the property. Checking the zoning at the planning department website, I learned the zoning is RMF-8, which means the area can be developed to a density of eight housing units per acre. So the 13,000 sq. ft. lot could be redeveloped with a duplex since in this zoning district, each dwelling unit requires 5,000 sq. ft. The maps the Planning Department has online can also show you the property boundaries. Never assume that what you see is the legal limit of the property. Fences are not always on property lines; what appear to be roads or off-street parking may really be in the right-of-way or conversely may be part of the private property. Even when you look at online maps though, property lines may seem askew or misplaced. A planning staffer mentioned that happens some times; map lines and reality do not match up. That is part of why I suggest visiting the Planning Department in person. Among other things you can learn from these maps is if the property in question has had code violations; or, if the neighbors have. You can also learn if the violations have been addressed and resolved. There are a dozen or more specific questions you may have in doing a thorough due diligence process before buying, or even making an offer to buy a property. Among others that can be researched o-line include:• School attendance areas• Property sales (by street, subdivision, etc.)• Sex offender locations• Soils maps (especially relevant in some Orchard Mesa and Redlands neighborhoods)You may also want to view the County Assessor's website for much more detail on the history of the property, current and past tax-assessed values and recorded documents.On the topic of recorded documents, if you are buying a bank-owned property, some buyers have the title company do a supplementary title search to look for "clouds on title." But, that is usually a decision made after you have an accepted purchase offer on the property.I guess you can tell I am a big fan of using the county resources to the greatest possible extent. Not only are the resources complete, extensive and generally accurate, the staff in the county offices here are always professional, courteous and very happy to have everyday folks like you and me using the resources.Doug Van Etten is an associate broker with Keller Williams Colorado West Realty and is also the founder/organizer of the Real Estate Investors Network (REIN). Van Etten has been helping homebuyers, sellers and investors with their real estate needs since 1992. Contact Van Etten at DougVE@kw.com or 970-433-4312. For information on the REIN, info@REIN-WesCO.org.