People with dementia may have an altered sensitivity to indoor environmental conditions compared to other older adults and younger counterparts. This paper, based on literature review and qualitative research, provides an overview of needs regarding thermal comfort and the design and implementation of heating, ventilation and air conditioning systems for people with dementia and other relevant stakeholders through the combined use of the International Classification of Functioning, Disability and Health, and the Model of Integrated Building Design. In principle, older adults do not perceive thermal comfort differently from younger adults. Due to the pathology of people with dementia, as well as their altered thermoregulation, the perception of the thermal environment might be changed. Many people with dementia express their discomfort through certain behaviour that is considered a problem for both family and professional carers. Ethical concerns are raised as well in terms of who is in charge over the thermal conditions, and the protection against temperature extremes in hot summers or cold winters. When implementing heating, ventilation and air conditioning systems one should consider aspects like user–technology interaction, diverging needs and preferences within group settings, safety issues, and minimising negative behavioural reactions and draught due to suboptimal positioning of outlets. At the same time, technology puts demands on installers who need to learn how to work with customers with dementia and their family carers.