This apartment in a two-storied house built in the twenties of the past century, situated in the centre of Madrid belongs to the architect Marta Rodriguez y Arino. Its interior corresponds to two requests: to be maximally light and include the architectural office area. The house needed thorough repairs and it was seriously modified during them. The basement was deepened and an extra bottom level for the office has appeared. The floor of the terrace on the first floor had become transparent, because thick glass had been used. This floor is also the basement ceiling so the office is always filled with natural light during the day. The private areas of the apartment are on the second floor so the professional and private lives are separated. The whole interior reflects the author’s world-view; the house is full of light, clear and almost ephemeral.