You state the single-family home in N. Stamford on an acre of land has the same appraisal value as a condo in the downtown area of Stamford? More information (such as their addresses) is needed to answer your question correctly but I suspect that the home in N. Stamford needs a lot of work and may be a foreclosure as banks typically price them under market value to encourage multiple bids for a fast sale. The downtown condo may be newer and offer some desirable amenities within the complex. Homes in the downtown area are the preferred area in the city for condominium buyers because of the proximity to the train, I95, and all the amenities that downtown offers.
Hope this is helpful but please, feel free to contact me with the addresses as then I can give you a more accurate answer.
Prudential Connecticut Realty