Joe_Carrick

FAR - Floor Area Ratio

What areas are required to be included in the FAR calculations   

15 members have voted

  1. 1. What areas are required to be included in the FAR calculations

    • Living Areas (Habitable Rooms)
      15
    • Garages
      10
    • Mechanical Rooms
      10
    • Balconies - not covered
      2
    • Balconies with Roof
      5
    • Decks - not covered
      2
    • Decks with Roof
      5
    • Porches - not covered
      2
    • Covered Porches
      6
    • Shops, Storage Sheds, etc
      3
    • Basement - unfinished
      5
    • Basement - finished
      9


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I've found that different jurisdictions require different areas to be included in the Floor Area for the FAR calculation.

I'm trying to put together a set that would cover as many cases as possible.

 

Please respond to the Poll indicating what areas your local(s) require.

 

Thanks.

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...and there are jurisdictions that ignore FAR and use LOT COVERAGE in various forms to calculate home size/coverage.

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1 minute ago, parkwest said:

Basement?

I would normally consider the Basement only if it were Habitable Space - aka "Living Area" - or could be converted in the future.  It's probably something most building departments would want to count just based on the future possibility.

 

I will add to the POLL.

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Some areas where I've built homes included the basement in the total living area, others, only if it is finished.  Some places, only above grade area counted.

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This list misses a number of factors, e.g.

How stairs are counted (some cities include each floor, some include only once)

Architectural projections, such as fireplaces.

Covered porches, may or may not be included depending on how many walls are open.

Height of decks/exterior stairs (below X number of inches of grade, may not be counted, or counted in lot coverage but not in FAR)

Ceiling height of basements relative to grade: above X number of inches above grade, may be counted.

Second/third floor "equivalents," where space that is taller than "X feet" may count.

 

This is just off the top of my head. I'm not sure that you'll be able to come up with a "one size fits all" scheme. Good luck!

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Most cities around here go by the lot coverage codes and those are different for each city, some have the FAR method also. I cannot remember all of them so for each project I have to go to that city's  website and read the zoning codes, ordinances  and figure it out. I deal with 50 different cities so it's always a crap shoot ,as over the years they all change.. Good luck with this poll.

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Joe:

 

you've added new choices to the poll but there is no way to re-do our voting ?

 

Lew

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Here it is the sq. ft. of the house itself doesn't matter if it is open below, stairwell opening or not

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In Sonoma Ca, it looks like a garage may count or not, depending on weather it is detached, or not.

Should Joe add detached garage to the list ?

 

FAR for a district in Sonoma.jpg

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So Far, it appears that most do not include Decks and Balconies - but all other enclosed above grade rooms are included.

More votes are needed to get a realistic set of data.  Please vote if you haven't already.

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59 minutes ago, Joe_Carrick said:

So Far, it appears that most do not include Decks and Balconies - but all other enclosed above grade rooms are included.

More votes are needed to get a realistic set of data.  Please vote if you haven't already.

 

Joe,  the votes are a waste of time.  It varies between jurisdictions.  For example,  decks and balconies are rarely included unless......  blah blah blah.  You are wasting your time trying to work this out.  This is one of the reasons that we users must be able to determine which spaces to include in the FAR and the COVERAGE.

 

This is also one of the reasons I asked for PLINE LABELS.  With PLINE LABELS I was assuming that CA would help us out  in determining the area analysis tabulations.  

 

I am so fed up with trying to get CA to listen to what I/WE need,  this may be my last post on this topic.  The Alaskan Son has been the only person so far that gets this.  Using Alaskan Sons method,  I can get what I need.  I absolutely love what Michael did for me.  It cost me a small fortune to get him to write the code,  but it has been worth every cent.  

 

This crap that CA give us  (THE LIVING AREA)  is useless to me.  Let me give you an example.  

 

I am working on a project and I will need to graphical show the City how I came up with the area for the FAR.  How do you do it?  How does CA do it?  You guys can't do it.  But I can do it by using the PLINE,  dimensioning it,  an then turning on the PLINE LABEL which will give the area of the PLINE auto.

 

Let me state this again.  We need  to be able to graphically show the area and to be able to dimension the area.  And god forbid.....  and it happens on every job of mine....  any changes to the area should be auto updated.

 

I understand that you think by giving a space a certain label,  it will be  included in the necessary area....  but how do you explain that to a plans examiner?

 

 

 

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Scott,

 

It's interesting that you think I haven't thought this out.  I have a PLine System that works exactly as you want with total flexibility to include whatever areas you want.  I've had this system since X8 was released.

 

The basic difference between my system and Michael's it that you don't have to change any formulas in macros - just what PLines are to be included.

 

OTOH, some users want to use a combination of Rooms and PLines.  It's just a matter of using room data for the building.  A couple of things I've requested from CA are attributes for rooms include_in_FAR and include_in_Lot_Coverage.

 

That would make it totally flexible. 

 

I agree with you that include_in_living_area isn't very useful for FAR but it is useful for Real Estate Building Analysis.

 

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As others have mentioned, I also deal with a dozen cities each with variations.  Most of them use both FAR and Lot Coverage.  Accessory structure calcs change things too - in a project I just worked on, if they are over 120SF, they also count towards FAR, but if less, than they don't.  Roof overhangs are another variable that will count towards FAR depending on their depth.  A deck might or might not count depending on whether the railing around it is open or closed...  And another challenge is that the cities keep adding and changing things, so I still have to recheck all the zoning regs every time for every project to make sure I am accurate.  It'd be great to have some of this be more automated, but it is certainly a challenge. 

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IMO there are too many variables per jurisdiction. Some will even "discount" the first x-amount of square feet for certain areas, such as garages or accessory dwellings.

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Agreed with most of what has been said- mainly too many variables between jurisdictions.

We have FAR and lot coverage both.

The areas to be included in each are somewhat similar but there are differences.

 

FAR takes in all living space on all floors above grade and a certain amount of garage space based on the size of the lot.

 

Lot coverage takes in the overall building footprint including covered decks and porches.

 

Then impervious area calcs must be provided for runoff containment.

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OK, I am going to make a suggestion to CA to add room attributes:

  • include_in_FAR
  • percent_FAR
  • include_in_lot_coverage

This will allow total flexibility in specifying what should be included or not.

  • Upvote 1

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Like it-

Then maybe they could be included in a schedule to show the calculations and sent to layout.

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4 minutes ago, RL-inc said:

Like it-

Then maybe they could be included in a schedule to show the calculations and sent to layout.

I've been working on a macro package to do exactly that - using the room data combined with some Plines for the actual site areas.

 

These attributes will just make it much easier to control.

  • Upvote 1

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In the interest of simplicity just adding the following would work:

  • percent_FAR  (0 -100)%
  • percent_lot_coverage  (0 -100)%

;):rolleyes:

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Depends. Is garage attached? Ect.

 

What is the 'Floor Area Ratio - FAR'

The floor area ratio (FAR) is the relationship between the total amount of usable floor area that a building has, or has been permitted for the building, and the total area of the lot on which the building stands. This ratio is determined by dividing the total, or gross, floor area of the building by the gross area of the lot.

A higher ratio is more likely to indicate a dense or urban construction. Local governments use FAR for zoning codes.

BREAKING DOWN 'Floor Area Ratio - FAR'

The FAR accounts for the entire floor area of a building, not simply the building's footprint. Buildings with varying numbers of stories may have the same FAR value. For example, the FAR of a 1,000-square-foot building with one story situated on a 4,000-square-foot lot would be 0.25. A two-story building on the same lot, where each floor was 500 square feet, would have the same FAR value.



 

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