You are not allowed to enter without the permission of its owners, whether they are in the house or not.
(O believers! Do not enter any house other than your own until you have asked for permission and greeted its occupants. This is best for you, so perhaps you will be mindful. If you find no one at home, do not enter it until you have been given permission. An-Nur 24: 27
لا يجوز دخولها إلا بإذن أهلها سواء كانوا موجودين أو غير موجودين.
(يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تَدْخُلُوا بُيُوتًا غَيْرَ بُيُوتِكُمْ حَتَّىٰ تَسْتَأْنِسُوا وَتُسَلِّمُوا عَلَىٰ أَهْلِهَا ۚ ذَٰلِكُمْ خَيْرٌ لَّكُمْ لَعَلَّكُمْ تَذَكَّرُونَ ﴿٢٧﴾فَإِن لَّمْ تَجِدُوا فِيهَا أَحَدًا فَلَا تَدْخُلُوهَا حَتَّىٰ يُؤْذَنَ لَكُمْ ۖ) ﴿) النور 24: 27