Back to the Original Question....how to tell the age of a home if there are no records??
The "toilet method" is only accurate if the toilet is original. If the home is very old, that is not very likely.
Style is a very good way. For instance, Bilevels, High Ranches and Split Levels were not built in the 1930's.
There is a period of time in every state when a style of home is popular. In my state, colonial style homes were 1920's to 1940's, then cape cods in the 1950's, ranches in the 1960's, splits and bi's in the 1960's thru 1980's , etc.
Experience in your area helps; discussions with long-time area realtors will also be helpful.
Also, get a book on home styles. I have a very comprehensive one, and a photo is worth 1,000 words. The book has hundreds of photos with just about every style of home I have ever come across.
Finally, it is good to know building components. Take the electric service, vor instance. Once upon a time (1920's) there was a method called "knob and tube", which used ceramic insulators so fabric covered wires could pass through wood without causing a fire.
The electric box may have buss fuses (very old) glass fuses (old) or circuit breakers. The size of the service is a bit of a give-away if it is original. A home with original circuit breakers built in the 50's may only have a 60 Amp service; by the 60's 100Amp was common and nowadays 200Amp is minimum.
Building and plumbing materials give similar clues; rather than be long-winded here, I suggest you seek some guidance from professionals or ask a realtor friend if you can go along on some older or unique homes tours just to be able to see with your own eyes what the different styles look like.
