Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The room in a dream indicates the wife. Its beauty and spaciousness indicate the wife's beauty and good character. It may also indicate security from fear.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The room indicates the world. Whoever sees himself in a decorated room will gain a spacious world. An unknown room indicates the grave.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The room is interpreted as a woman. A high room is high status and honor. Whoever sees himself building a room will marry a woman and collect wealth.