If McMansions are too big, and a lot of critics would say this is the case, it is less clear about how much space people actually need or should be allotted. Here is a suggestion from the director of sustainability of Sierra Club Green Home:

Indeed, magazines like DWELL, and websites such as Inhabitat.com — both leaders of architectural style and design – showcase smaller homes for families of up to four members. Usually these are in the 1,000 to 3,000 square foot range, built with fully sustainable materials and state-of-the-art energy efficient HVAC systems. Upon considering this trend versus the longer-standing bigger is better, Sierra Club Green Home.com proposes a new industry standard that balances our longtime desire for lots of space with the current and future need to downsize: one thousand square feet per inhabitant, max. So, a family of four would get up to 4,000 square feet, a childless couple would have 2,000 feet or less, and so on. Sorry, pets don’t count as people (although my personal bias is that having a large dog in a very small space is not healthy for the animal).

No doubt hardcore environmentalists will think this plan is too liberal, but I believe we have to start somewhere and we have to be realistic about the ability to change long-standing philosophies overnight. Perhaps ultimately downsizing should mean 750 or even 500 square feet per inhabitant? For now, however, in this first incantation, I think the 1,000 feet per person proposed by Sierra Club Green Home makes sense.

We then need to hear why this figure, 1,000 square feet per person, is correct or defensible. Just because people are designing homes containing 2-3,000 square feet does not mean that is the way it has to be. This is still a lot of space by the world’s standards as the average new American home in 2010 was 2,392 square feet. I’m sure we could get some input from environmental psychologists about how much space Americans need to feel comfortable at home while sociologists and others could provide insights into how Americans and others interact within houses.

This reminds me of what I have read about the design of homes in the 1700s and 1800s which was influenced by the idea that individual members of the household needed their own spaces so houses were carved into more rooms as opposed to having bigger communal spaces. The recent trend is back toward more open, “great room” spaces but these homes likely also include the private spaces (remember the articles about “mom caves” from a while back? See here and here) that people are used to. So if people should live with 1,000 square feet per person or less, what gets cut from the average home?