Dreaming of an attic has multiple options to explain. Listen carefully to your own feeling, intuition. You can experience it positively as well as negatively. The attic is connected to your heart, your source, your base, your inner home and in some cases your parental or past life home.
Dreams or visions of the attic tell you of reaching the highest part of your heart, your true self, and your deepest hidden desires. Your crown chakra and/or the 6th and 7th dream layer or energy layer.
Another explanation is, finding your intellect and seeing new ideas, possibilities and opportunities. Experiencing promotions or mental improvements. You gain knowledge, wisdom, spirituality, and the connection with the higher within yourself.
Another explanation is that the attic also represents forgotten and hidden or repressed thoughts and memories that you must investigate and resolve so that it can be revealed. The attic is part of a house dream that represents you a part of your purest and true self (your soul).
As an additional explanation, the attic can represent your dark and dark side (inner demons) qualities or fears that you would rather not face and/or that you do not always want to experience consciously. That which you do not want to show and/or share to the outside world and/or yourself.
With attic dreams, look very carefully at what is present in the attic, the color, the shape, the material, the status of the roof, etc. This tells you a lot about how you can explain the dream.