Abstract
Developing new residential buildings is a complex task that requires balancing various conditions and preferences within technical regulations. A survey of individuals who recently purchased an apartment in a new housing project assessed their satisfaction with their homes and identified the types and sizes of apartments occupied by different age groups. The results from 536 participants indicated that overall satisfaction was influenced by both apartment size and layout, with the number of rooms playing a more critical role than their dimensions. The living room and kitchen were crucial for satisfaction across all apartment types, especially compared to the bedroom or secondary spaces, and should be prioritised in the design. Apartment satisfaction was generally unaffected by floor position, although a lower satisfaction level was reported for units on the first floor. Regarding age distribution, individuals over 70 years old, on average, live in 70% more space per person than those between 40 and 50 years old, due to a combination of economic, historical, and demographic factors. Additionally, the average number of residents in apartments with more than three bedrooms is fewer than three. These imbalances contribute to unnecessary material usage, leading to higher prices and increased carbon emissions. Prioritising spaces linked to satisfaction, along with downsizing solutions acceptable to residents of all age groups, can effectively reduce cost and life-cycle emissions starting from the conceptual design phase by decreasing the floor area per capita. Such a reduction can be achieved by designing compact units with high space efficiency and incorporating shared areas to minimise private apartment spaces. This process necessitates greater awareness among target groups and the application of technological advancements, such as parametric tools that optimise composition and perform environmental assessments for each alternative. Tailoring apartment layouts without compromising the quality of living requires different measurement units, such as CO 2 -eq per resident, to enable a fair comparison of various housing options with the same construction and material types, and, explicitly, to best address housing sufficiency.