1 room house of 21m² in London

Single bed.I live with my husband, daughter and mum. In a 5 bedrooms semi-detached in Mitcham, rural area of London. We have 2 rooms. 1) Private double room- Ensuite and 2) Mitcham's charm-listing, both on 1st floor. We operate a keyless or remote opening the front door.We have a small dog name Kiki, He is a small chihuahua.