Students with autism spectrum disorders tend to remain calmer and more focused in simpler, low-demand environments, given their propensity to react negatively to high stimulation and their vulnerability to distractions – both of which abound in the inclusive classroom setting. These students also tend to have difficulty with the information processing demands and pace of mainstream environments, many of which contain too much auditory input and precious few visual supports.[1] It has been demonstrated that children with learning and behavioral disorders do better in learning environments in which the primary lighting source is not fluorescent. Natural light is particularly beneficial to academic achievement and reduction of symptoms. 

I suspect that a Montessori type of learning environment would be a preferred situation for children with autism.

TEACCH (Training and Education of Autistic and Related Communication Handicapped Children)

TEACCH is a special education program that is tailored to the autistic child's individual needs based on general guidelines. What makes the TEACCH approach unique is that the focus is on the design of the physical, social and communicating environment. The environment is structured to accommodate the difficulties a child with autism has while training them to perform in acceptable and appropriate ways.

Building on the fact that autistic children are often visual learners, TEACCH brings visual clarity to the learning process in order to build receptiveness, understanding, organization and independence. Instructions may be presented in pictures rather than words, and tasks may have visual prompts (e.g., grooves to indicate where to place items, pictures of each step of the task, etc.).

The children work in a highly structured environment which may include physical organization of furniture, clearly delineated activity areas, picture-based schedules and work systems, and instructional clarity. The child is guided through a clear sequence of activities and thus aided to become more organized. The classroom instruction is designed to accommodate learning styles characteristic of autism spectrum disorders. For example, because classroom noise or intrusions from peers may be distracting or aversive, individuals with autism spectrum disorders often work at their own workstations rather than with classmates, though small group instruction also occurs. Because transitions from one activity to another may be difficult, individuals with autism spectrum disorders may have a highly structured schedule placed at their workstations.

It is believed that structure for autistic children provides a strong base and framework for learning. Though TEACCH does not specifically focus on social and communication skills as fully as other therapies it can be used along with such therapies to make them more effective. TEACCH is widely considered to be a plausible intervention approach. One small but well-designed study indicated that parent training provided by TEACCH may accelerate the development of cognitive and self-help skills. Other aspects of TEACCH such as classroom instruction have support from preliminary but have not been evaluated in peer-reviewed studies with strong experimental designs.

TEACCH seems to be a very well considered treatment program that focuses on adaptive coping as a strong part of creating a base for success. It pays attention to the sensory environment, which is of crucial importance in giving the child an opportunity to manage their reservoir. It pays close attention to their sense of control and predictability, also aiding stress management. It seems very well put together.