* The term "original house" means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date).
* Ystyr y term "tŷ gwreiddiol" yw’r tŷ fel y cafodd ei adeiladu gyntaf neu fel yr oedd ar 1 Gorffennaf 1948 (os cafodd ei adeiladu cyn y dyddiad hwnnw).