Calculating Square Footage in San Francisco: “Comment du Jour”

To think that I always choose snarky comments for the “Comment du Jour” would be silly. As I always say, the comments are full of information, but I know not all of you read or follow them. So…a reader (FogCityBrit) provides a horses mouth (City Assessor) account of calculating square footage: (An update on Chelsea would be nice too, you know.)

Having recently finished construction on a ground up new single family, I had occasion to discuss how the ‘tax’ sqft (I presume this is what is listed on the MLS) is calculated by the City assessors office. Here is my question and their response:

Q. Do you have guidelines on calculating the sqft? is it the gross area

(i.e. to the outside extent of the envelope)? Should voids be deducted?

A. For detached houses, measure from the exterior face of the walls.

· For attached units (i.e. – townhouses and side-by-side duplexes), use

the centerlines of the common walls as the outside dimension. It may be

easier to measure from the inside surface wall and add 6 inches to account

for the common walls on both sides.

· For condominium units, measure from the inside surface wall since the

airspace is what is being purchased. Remember to include the partition

walls within the condominium unit as part of the GLA.

· Begin measuring from any corner and work your way around the house.

· Measure to the nearest inch.

· Draw a separate floor plan for each level in the house. Do not assume

that each floor is identical.

· “Square the house” by checking whether the measurements of parallel

sides of the structure are equivalent. The total front building measurement

should equal the total rear measurement. The total left-side measurement

should equal the total right-side measurement. Minor discrepancies may be

due to the corners of the structure not being at perfect right angles.

Exclusions from the finished area:

· Attached garages – Use the interior wall surface of the garage next

to the house as the outside wall of the house.

· Openings to the floor below – Subtract the opening from that level.

· Exclude porches and converted garages that are not finished or

considered habitable living area.

· Chimneys that protrude beyond the exterior surface are not included.

— Houses are described by their total room count. For example, the

shorthand designation 5/2/2 describes a house with 5 rooms, 2 bedrooms and 2 baths:

· In general, a kitchen, bedroom, living room, dining room, den, or

office study is a room. Bathrooms, laundry rooms, sunrooms, and storage

rooms are not counted as a room.

· A bedroom should have a door, a window that provides for an emergency

exit, natural light and ventilation. In modern homes, a bedroom always has

a closet. In many older homes, closets were not included.

· A full bathroom includes a toilet, sink, a bathtub and/or shower. If

the bathroom only has a toilet and sink, it is a ½ bath. If it only has a

toilet, it is a ¼ bath.

— Attics, Lofts and Low Ceilings:

· Level ceilings must be at least 7 feet high. If a room has a sloped

ceiling, at least one-half of the finished floor area must have a ceiling

height of at least 7 feet. Otherwise, omit the entire room from the total


· Lofts and finished attics must be accessible by a conventional

stairway or other access. If you need to reach the loft by climbing a

ladder, then it is not part of the finished area.

— Guest Cottages, Detached Rooms:

· Finished areas that are not connected to the main residence by a

finished hall or stairway must be listed separately. If you have to leave

the house to get to the room, it is not part of the finished area.

14 thoughts on “Calculating Square Footage in San Francisco: “Comment du Jour”

  1. “For detached houses, measure from the exterior face of the walls.”

    What if the detached house have multiple floors? Do you measure the exterior walls of each floor?

  2. John,

    Yes. Measure the exterior walls of each floor, then add the floors up. Subtract voids (double height spaces). Exclude the garage. Did your house just get bigger?

  3. subtract voids (double height spaces).

    from my understanding, this is not true.

    cf the post (where was it?) about the loft which has 900 first floor and its MLS shows 1800 (2 virtual FULL floors) instead of 1200 (900main floor+300 of “inside balcony”).

    Or are the live/work lofts another loophole in the sqftage?

    I just measures out our house, and I find 3% more than numbers on the blue prints…. ok – not that bad.

  4. Sophie, as I mentioned in the original post, this guideline was sent to me from the tax assessors office. It clearly states to exclude openings to the floor below. Not much room for interpretation or debate on that! They are the final authority on this matter.

    My house contains a double height living space, the area for that volume is counted once, not twice; As it should be, and as is logical. As another poster mentioned sqft is but one factor. Perhaps cubic feet would be a better measure!

  5. Chelsea — Mourinho was not happy with the level of autonomy he was given. The big man was not happy with the style, results, or attendance. Did you see what happened during the Aston Villa game when Abramovich walked out early, all cameras on him? Ouch. That was apparently the writing on the wall.

    But that’s only half the story, as they say. In my opinion Mourinho left because he knew they were no match for the revamped young Gunners side! Cesc Fabergas, y’all!

  6. Hi Guys – Is it easy to just get unwaranted space converted quickly right before one sells? If you have 100/sqft of unwarranted, but warrantable spce, doesn’t it behoove you to convert say 3 months before you plan to sell if your neighborhood is selling for $800/sqft or $80,000 more bucks?

  7. Depends on what “easy” means to you.

    You know, I’ve read and contributed to this blog for a few months now..and my observation and underlying perception is that it’s really about just one thing:

    Do it quick.

    Do it as cheaply as possible.

    Avoid permits at all costs.

    Cheat on the square footage.

    Flip it.

    Take the obscene, greedy profits.

    Start over.

    No, I’m not naive. No, I’m not stupid. I’ve been an SF resident for 33 years and a homeowner for 23 years.

    Anybody care about quality of life in this great city?

  8. Anybody care about quality of life in this great city?

    Yes, we do. Thats the reason why we were so reluctant to buy a house with ANYTHING done, and we would mentally add “clean to the studs” toany house we would visit. OK, most houses could be moved in quite of fast, but unless you live in a house, you cannot feel needed improvments.

    So… we bought a perfectly movin house, … and we redo it.

    yes, it’s not financially sane (at least not toflip the house), but quality of life is great… you tailor your house to the tiniest details – incorporate a TON of green features, and the house becomes a home.

    What (sorry, I dont mean you, I just generalize) architects miss most is long term maintenance. We made some changes to the blue prints to make that drain 4 times easier to unclog/clean, that area to hose down, this item to self clean etc…

    When visiting, most of houses were screaming “last minut remodeling as part of the staging” and we would automatically deduce the amount of money to undo the damage from the potential price.

    Yes, we didnt get one specific house that “presented” better than ours (and was red tagged by the city for illegal work)… but for a better price, we got nearly twice as much footage, and we are making it present at least as well as the other one AND it was done with permits.

  9. Nobody calls them “blueprints” anymore…that term went out about 15 years ago.

    But I digress..

    Idle rants like the previous one just bore me. the spelling and grammar just get worse and worse.


  10. hey.. my blue prints ARE blue (I just rolled them again)

    and for spelling… I do what I can. English is my third language :-(

    [Editor’s note: Sophie, Thank you for not getting worked up about Duggo’s comment. I had my finger on the delete button.]

  11. Blueprint is still a term that is used widely Sophie. Nothing to be ashamed of as for your language skills. Some people on here like to take unnecessary jabs. Be proud of the fact that you speak three languages.

  12. Is it true that the 2nd level of a loft cannot be more than 30% of the total square footage of the unit? Is there a site that drills down to this level of detail to make sure our construction plans are legit and can be warranted?

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