You may still apply to adopt a child whose parental rights have been terminated where there is no risk of the child returning home. A home study is your opportunity to speak about your strengths so the best possible match is made. Yes, you will become very close to the social worker assigned to your family, but cleanliness is not the most accurate predictor of a successful permanent family. In fact, a little mess and chaos is generally a sign of high tolerance for children. Spend your time reading and attending workshops about special needs children rather than cleaning your house.
Many parents live in apartments and rented dwellings.
In fact, sharing rooms is a good lesson in cooperation. It can take from six months to two years, depending on the challenges your family is willing to accept. There is no cost for a home study or the training for families willing to parent a child with special needs. There may be some costs to becoming licensed for foster care, such as physical exams for all family members. There may be some costs related to matching with a child, such as a meal in a restaurant or a hotel if the distance is far.