House Size, Square Foot Costs and Economy of Materials

or: Size Matters

I have some issues with the idea of building small which I will see if I can explain. I really appreciate Sarah Susanka’s book “The Not So Big House” but most of the houses she illustrates the book with are still fairly large. Yes, 2500 square feet instead of 4500 square feet is a good thing but it is still rather large and the jogs in plan and overly complicated roofs that many plans use to reduce the raw square footage seem wasteful.

Lets assume that you are at least meeting and hopefully exceeding energy codes. (remember these codes represent the bare minimum! - Vermont has an energy code although there is no residential building code in most towns) A simpler plan that is 20% bigger is not going to cost 20% more to heat and/or cool and it may even cost less. A simple form may also use fewer raw materials or at least result in less waste. Simple forms, particularly ones that have cleaner roof lines, are less likely to need renovation and repair in the long run.

I also like the idea of designing as much flexibility into a plan as possible so that a home is not just custom tailored to the current residents but will fit a wide variety and quantity of people over the next several hundred years. This often means adding a little more area to allow for multiple furniture layouts, the possibility of wheelchairs and walkers, age related issues on both ends of the spectrum, big dogs who like to sprawl in the middle of the most traveled route, the list goes on and on. There are a lot of small houses around here that were built to perfectly fit their tenants but I am often called in when the next person comes along and can’t fit. A good architect will help plan for the maximum amount of contingencies. This is a large part of the value an architect can add to the project and the subject of another blog entry someday.

A current project that had me thinking along these lines is a smallish house with a large floor plan. The main floor has 1060 square feet. I could knock out 160 feet fairly easily but the spaces would not be quite as flexible, a few tight spots would crop up, future possibility of a first floor wheelchair accessible bath would not be an easy retrofit, there would be less room around the woodstove for drying racks, the pantry would be smaller, necessitating more ($$) cabinetry in the kitchen, etc. The site is conducive to a walk-out basement. Since basements are required to be warm conditioned space (75% of the way toward finished space) I can use this space for bedrooms, offices, a play room, media room, storage or many other uses and it now officially becomes finished space (add 860 square feet) except for the utility room. Raising the roof by three feet and adding a few simple shed dormers allows me to use the attic space as well. We get lots of bang for the buck since we are building this house with structural insulated panels www.foardpanel.com so the loft or attic space is finished off anyway. (Add 675 square feet – some of the main floor has cathedral ceiling) Suddenly my small 1060 square house has ballooned to 2595 square feet and the only substantial visible difference is that the roof is three feet higher. When I look at square foot costs, they have gone way down. I have created a house 2 ½ times larger for about 25% more materials. The outward appearance of the house changes very little. The larger house is much more likely to serve the occupant’s changing needs without using more energy and few additional materials. Interestingly, the larger house will also be valued higher which, unfortunately, means higher taxes.

Size isn’t everything.