Hi, apologies for the delay in getting to this question.
To dream of a childhood place that has warm or happy memories for you, as in your school, can symbolise your longing to return to a simpler time in your life, and to experience the same connections as you had then, as in Sister Pauline.
The walls in the school being neglected can indicate a feeling of neglecting these childhood qualities or dreams you once had for yourself, and an unconscious awareness of putting the needs of others before your own. There can also be something of a need to move on from your past, and a readiness to move into a new phase in your life.
The others in the dream, particularly your aunt/sister may symbolise another part of yourself, such as those aspects of your personality that you may have repressed or neglected, as we may project onto others the contents of our own unconscious. In this way, Dalia in your dream, and the words and tone used, can represent the ways in which you may be disrespectful or mistreating a part of yourself.
The foundation of the new building and the building materials symbolise self development and maturing. Water in a dream , such as the sea, generally represents emotion, and the colour of the sea can represent a muddying of the water, or emotions, or a block that needs to be addressed to return to the clarity you seek.
The reference to the cat can have many meanings, dependent on your relationship with cats. As you appreciate cats, this may be symbolic of your positive feminine qualities, and reference to fertility, a possibility or longing for new growth, and barriers or difficulty in fulfilling or achieving this desire.