What is Your Home’s Power/Weight Ratio?
If you’re a car-nut, you know the importance of a car’s power-to-weight ratio. You know that a car with 300 hp and weighs 6K lbs will accelerate slower than a car with 150 hp and weighs 1500 lbs because each horsepower in the former car must drive 20 lbs, whereas each of the latter car’s horses must propel 10 lbs (adjusting for things like aerodynamics of course). Improving power-to-weight ratios is why the best marathoners stay rail thin and people buy carbon fiber spoke nipples for their bicycle wheels. Lowering weight is often the easiest strategy for gaining effective power.
But power-to-weight can be applied to things other than locomotion. Take architecture. To illustrate, consider these two scenarios:
- HOUSE A is a four bedroom house with 3K sq ft of floor area occupied by a family of four. Of the 3K sq ft, 1200 sq ft are actively used. Monthly housing expenses total $4000 (mortgage, taxes, utilities, maintenance, etc). Monthly cleaning time, which includes yard care, equals 15 hrs. Monthly transportation expenses, which includes two requisite cars, equal $1500. Combined commute times equal 2.5 hrs/day, which includes work, school drop-offs and regular trips.
- HOUSE B is a three bedroom townhouse with 1500 sq ft of floor area, also occupied by a family of four. Of the 1500 sq ft, 1000 sq ft are actively used. Monthly housing expenses total $3500. Monthly cleaning time equals 6 hrs (yard maintenance is handled by condo association). Because of close proximity to amenities and public transport the family only needs one car. Monthly transportation expenses equal $1000. Because one adult works from home in a bedroom that converts to an office and kids live near school, combined commute times equal one hr/day.
In both cases, power is represented by size, which is like the action potential of a space. House A’s size affords four bedrooms, which means you can sleep four to eight people–maybe more–all at once. It affords a dedicated living, dining and family rooms, which allows you to entertain up to 75 people. It affords four bathrooms, allowing up to four people to go to the loo at the same time. Usable power in House A equals 750 sq ft/person; 375 sq ft/person in House B. Used power–how people actually use the space–is 300 sq ft/person and 250 sq ft/person, respectively.
“Weight” are the things–bills, maintenance, commutes, natural resources used, etc–that allow you to use the power. For the sake of this argument, let’s say that each dollar represents three minutes of time ($20/hr). House A’s weight equals $7300/month and B’s $5220, or 365 and 261 hours.
Therefore, the power to weight ratio of House A is 3000 sq ft/$7300 or $2.43/sq ft per month; in terms of used space, that number is $6.08. House B is 1500 sq ft/$5220 or $3.48/sq ft per month, and $5.22 for used space. In terms of time, House A is 7:03 and 18:00 mins/sq per month (usable/used) and House B is 10:20 and 15:66 mins/sq ft per month.
In both cars and architecture, increasing power increases weight. All things being equal, a V8 engine is going to weigh more than a V4 (not to mention requiring more fuel). All things being equal, a big home will cost more time and money to maintain, require longer commutes, use more natural resources, etc, than a smaller one.
When thinking about what features you want from your home–number of bedrooms, size, location–you must consider the weight that power entails.
This is not an argument to move into a tiny house, which have tiny “weights”–bills, cleaning schedules, etc. You can have minimum power requirements. At a certain point, you can only go so small before utility is undermined or negated altogether–before you can’t fit your children in the house, before you don’t have enough horsepower to move your car. But in our excess-erring culture, few of us get anywhere near those minimum values.
The importance of design can’t be understated in terms of assessing power. A couple weeks ago I met Scott Specht, one of the architects behind the Manhattan Mini Loft. The amazing little apartment, with its high ceilings, smart layout and choice of furniture felt much larger than its small footprint would have suggested. Specht said that he puts less focus on square footage than how space is arranged, how furniture and lighting are used and many other factors, all of which determine a space’s overall usability or, for the sake of this article, its power.
I am guilty of using a house’s square footage as a primary way of understanding its capabilities. A number is an easy thing to affix your mind to. But you can’t judge a house by its number. Whether talking about a 5K sq ft McMansion or 200 sq ft tiny house, raw power (i.e. square footage) must necessarily be related to its weight–usable space, the financial, time and even environmental costs required to maintain a home, etc–in order to understand its real performance.