Dear Mr. Lee I bought a house which was built in period 4, but sometime later, i still can't get information when, on terrace some of the previous owners built kitchen and bathroom. they are not under the same roof but have the same entrance as the rest of the house. those that qualify it as other period. My parents done the roof renovation this summer on their house (I still live there), the whole roof was changed and prolonged over balcony. does it changed house period 6 (was built in 1981) to period 7. Thanks a lot. Daria