Square Footages
Design and Construction Plans: Finished square footage all projects are calculated using the real estate standards noted below.
Real Estate (Industry) Parameters: Confirm with your states real estate association rules for calculating finished or ‘saleable’ square footage. Representing correct square footage is a big deal particularly when real estate is bought and sold. Below is a list of typically accepted parameters. Finished footage is a common term used for this ‘saleable’ footage- but it can be a misleading one as all finished footage does not necessarily count. Other criterion must be met.
*Finished footage is measured to the outside of the exterior walls. (Note the thickness of these exterior finished are not included in the control dimension calculations noted above).
*Walls and typical construction within that exterior wall boundary are included. Finished footage is basically a gross area, not a net net interior wall to wall area. Note room sizes (below) are a net wall finish to wall finish dimension.
*Finished footage must be conditioned.
*Finished footage must follow the code rules for “habitable space per the IRC. See section R303 Light, Ventilation and Heating, Section R304 Min Room Areas, Section R305 Ceiling Height.
*Lower level and basement footage is complicated. It being included is usually conditional on the exact grade condition and amount of daylight/glass present. See the design guide d6.4 for a graphic interpretation. And check with the local realtor association.
*Attic footage is frequently subject to the min ceiling ht/average ceiling ht restrictions. One key requirement is a min wall ht of 5′. Plans may differentiate ‘legal’ and ‘useable’ attic square footages. The listed legal footage will meet the code definition. The listed ‘useable’ square footage is by designer judgement useful space.
*Finished footage does not require a high level of finish to be included.
*Stair area can be included for both the departure and arrival floors.
*Open space within a vaulted roof or ceiling cannot be included where there is no actual floor.
*Cantilever floors can be included only if the floor space is useful. Cantilever floors or bay windows with raised ‘seats’ cannot be included.
Dimensions
Control Dimensions: These control dimensions refer to a consistent set of exterior dimensions that show in foundation plans up thru roof plans. They represent locations for all primary construction inside and outside corners for the house footprint and porches and decks.
Design Plans: Exterior dimensions on design plans use these same control dimensions. Interior dimension-when and if present- are to face of finishes.
Construction Plans: Exterior dimensions on construction plans use these same control dimensions. Interior dimensions/partitioning (‘walls+dimensions’ floor plans) are face of framing to face of framing.
Room Sizes
Design Plans: May show room sizes below room designations, and or may show room dimensions where appropriate and helpful.
Construction Plans: Do not show room sizes. For very accurate dimensions of all spaces and rooms check the ‘walls+dimensions” floor plans in the construction sets. These dimensions are typically face of framing to face of framing. Deduct 1″ to arrive at very accurate finish inside dimensions.