In title records, which are based on building permits, it is common to have two dates.
The first date is the date that the original home was built. A nice way, if the toilet is original, is to look at the date inside the toilet water tank.
The second date is called the "effective date", usually after an extensive remodel that changes the square footage of the living area.
Hope this helps.
Can't your title company do a title search on the propety? We have records which go back to the early "rancho" days here in Sonoma County which was the era before the gold rush or pre-1849.
You may wish to check with some of the older, established companies in the fields of surveying, builders, and other "sub-contractors'. The local builder's exchange might hold some information and many areas have local "history clubs" which know much about specific neighborhoods in your area.
Also, check the local newspapers "morgue" which conains all their past issues. You could possibly go back and find the original subdivision when it was being marketed!! As far as the style is concerned, did you have an appraisal recently?? The appraisers usually list the "style" on the form. If your in the midwest you could have any type of style ranging from Tudor to "Prairie" styles.