Hello

I am looking for a list of tenants of two houses in Saltmill, Saltash, Cornwall, and also for the original building plans.
I know, that the house was built somewhen between 1927 and 1930. today they are council houses, but maybe they used to belong to individual people once.
Is there a chance to find it out? And is there anywhere where I can find a list of all tenants/owners?
I also need to have a look at the building plans of both houses, if they might have been one at some point and if yes, when was the house divided then.
I know for a fact, that the whole street was build after 1907, because there is a map that shows that it used to be a field.
I am not sure if the records are kept in Plymouth, or in Saltash.
Thank you,
GPS Hella