a) John’s house is semi-detached. Correct.
b) Upstairs there is a bathroom. Incorrect. Correct version: Upstairs there are three bedrooms and a bathroom.
c) His living room have got a fireplace. Incorrect. Correct version: His living room hasn’t got a fireplace.
d) Outside the house there are two gardens. Incorrect. Correct version: Outside the house there is a garden.