The age of the home is not a good basis for comparison between homes. The price per square foot will not have much meaning by itself as well. For example a Burton Valley home could command $400 per sq ft if it is updated and smaller. A home closer to 680 may not pull $300 and lafayette homes in the Alhambra school district which are newer could pull $300 to $400 but have different algebra altogether. Since the most coveted areas of Lafayette are the older areas, the price/sq ft calculation should be compared locally.