Final answer:
The cost per square foot of housing can vary, with condos often having higher costs due to amenities while single-family detached houses might cost more for privacy and land ownership. However, pricing also depends on market conditions and preferences.
Step-by-step explanation:
On a per square foot basis, the type of housing that should be more expensive can vary based on a multitude of factors including location, amenities, and housing supply and demand. Generally, condominiums (a) may be more expensive per square foot because they often come with additional amenities such as security, a concierge, and maintenance services. However, this is not a definitive rule as single-family detached houses (b) might also be higher in price due to land ownership, privacy, and potentially larger lot size. Townhouses (c) and semi-detached homes (d) often share walls with neighbors, which can lessen construction costs and therefore possibly reduce the price per square foot compared to stand-alone houses.
It's important to note that 'more expensive' does not apply universally and this is a simplified explanation. Individual market conditions, historical price trends, and the appeal of different housing types to different demographic groups can greatly influence the pricing.