Square footage is an elusive unit of measure. Because it factors in multiple dimensions, it can be inherently difficult to visualize or estimate. In the world of real estate comps, lender appraisals, and construction costs, this figure is a commanding factor in assessing the value of your home. Because it commands so much influence and the actual methods of accurately computing it can vary, there is a lot of merit in having an intuitive ability to comprehend it.
Without training or familiarity though, this can be a frustrating endeavor to take on as a homeowner. Have you had an experience buying or selling your home when you have faced important decisions armed only with what feels like an over-simplified number and no context for how it was determined? Let us help you by breaking down the “what” and “how” in calculating square footage.
Let’s do the math.
The math behind determining square footage is relatively simple. Does the formula A = L x W ring a bell? To compute a room’s square footage, multiply the measurements from two opposing walls – the length and width of the room. You can acquire a fairly accurate overall total for your home by just adding the areas of individual rooms together.
Unfortunately, this is where the calculation tends to get obscured. Real estate agents, zoning municipalities, and contractors all use slightly different methods to determine square footage. Among these trades, there is a generally accepted standard, but no completely consistent or universal point from which the measurements are taken. In most cases though, the exterior footprint is the most reliable and widely applicable figure to use. This is potentially deceiving, however, because it includes the thickness of the house’s walls, which are not readily visible or experienced when inside the house’s living spaces.
Make it real.
The easiest way to conceptualize this abstract unit is to compare the square footages of more familiar things you use and inhabit on a regular basis. Here are some good examples to put it in terms that are more readily understandable:
King-sized Bed: 42 square feet. Most master bedrooms vary between 200 and 400 square feet OR a rough equivalent of 5-10 king beds.
Two-car Garage: One of the most consistent and regulated measurements in contemporary home building, 20’-0” x 20’-0” or 400 square feet is the standard protocol for this space.
Drop-ceiling tiles: Browsing listings on New Homes Guide from the office? Odds are that your building has at least a few spaces with prolific white acoustical ceiling tiles. These almost always come in the same 2’-0” x 2’-0” dimension. Add up the number of tiles in each direction and multiply them together to determine the square footage of your conference room for an easy comparison.
Three-fixture bathroom: This is one of the most conventional and efficient bathroom layouts around. Modern standards of code clearances and product dimensions put this room at an approximate minimum of 5’-0” x 8’-0” or 40 square feet. Would you have guessed that your bathroom is roughly the same size as your bed? This just demonstrates how abstract the raw number can feel.
Not all spaces are created equal.
In determining the overall square footage total of your home, there are a few exceptions and distinctions worth noting:
Finished vs. unfinished: Garages, Mechanical rooms, and Basements that are unconditioned (and/or generally unsuitable for year-round use) and not equipped with walls, floors, and ceilings similar to the rest of the house are excluded.
Above-grade vs. below-grade: Basements that are buried both wholly and partially (i.e. a walk-out basement) below ground are usually listed separately.
Double-height spaces: Foyers and Great Rooms with ceilings that extend multiple floor levels are only counted once.
Floor area: Bay windows and chimneys, which do not have space on the floor for you to “occupy” do not count towards square footage.
Stairs: Runs/treads and landings both count in square footage totals. They are measured as a part of the floor “from which they descend,” so are generally counted twice in a typical two-story home with a basement.
Do you have any tips or tricks you rely on to visualize square footage? Share them with us by leaving a comment below!
Guest blog courtesy of W.C. Ralston Architects, an architecture and planning firm that has built an enduring reputation for design excellence in homes, neighborhoods and communities across the Mid-Atlantic region. Learn more at www.wcralston.com.