Not much land is needed.
What is needed is good planning, administration, maintenance, design.
Special needs is tougher to handle than one special need.
Help has to be : medical, educational, residential, financial, for basic needs, play spaces, lots of light, air, breeze, natural beauty, open spaces ,parks, security, parking spaces, caregivers, aesthetics, good design,(we saw some really badly designed furniture there and wheelchairs),cleanliness, neatness, hygiene, food, washing area, sleeping spaces, lifespan services, cooking area, verandahs, washing area, big terraces etc... High rise building not the answer, probably.
Help has to be care, love, hard work, concern, compassion. But there is also a need for constant updating of knowledge.