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Thread: Building height limit

  1. #1
    Cyburbian Streck's avatar
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    Building height limit

    Many zoning codes appear to set 35 feet as the maximum height.

    What is the reason for 35 feet?

    Should 35 feet be to the peak of the roof?
    Should it be the highest habitable floor?
    Should it be to the window sill of the highest habitable floor?
    Should it be to the chimney top?
    Should it be to the ceiling of the highest habitable floor?
    Was this the height of most ladder fire trucks could reach?
    Was this the height of most water hoses could spray?
    Is this an aesthetic height that would be less than most trees?
    Is this a Fire Rating Bureau magic number? (If so, why?)
    Is this the height at which someone could reasonably be expected to survive if jumping from that height to the ground while waiting for the volunteer fire department to arrive?

    The reason I ask is that occasionally we have a request for a Variance to exceed that height. I would like to have a reasonable basis for evaluation of the requested Variance, and would like to know if the 35 ft height is still valid for anything.

  2. #2

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    It is my understanding that this represents the ladder height available on the fire engine that responds first (a Class A pumper), without having to call out a truck with a big ladder. But I suspect that fire service technology may have moved past that, at least in some places, and I would check with a particular fire department before relying on it. IF that is the logic, the height should probably be measured to the place where firefighters could access the roof, not the peak. Most building codes do use an average height from grade, and I suspect that zoning should follow the code in this instance, except perhaps in zoning districts where there are special reasons for limiting height or requiring particular roof styles. It would be important to coordinate your definition with any design review or historic district requirements.

  3. #3
    Cyburbian ablarc's avatar
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    This thread makes my blood boil. Not you, Streck: the mere fact that you have to ask this question.

    Itís absurd to design our cities to suit the Fire Department. We should design the fire departments to suit our cities.

    There is no aesthetic justification whatever for a height limitation. It would not serve beauty to prevent North Church from sticking up above Bostonís North End; and except in Paris, Budapest and a few other boulevard cities a height limitation contributes nothing to the coherence of the cityscape. Bostonís Financial District makes a powerful aesthetic argument for the desirability of mixing tall buildings with diminutive old relics.

    Finally, height is not the defining aspect of scale, despite the widespread misconception that it is. Tear down half a block of a Paris boulevard and replace it in your mind with a standard one-story supermarket and youíll see for yourself. The primary definer of scale is building footprint (a distant second is articulation and detail), and it is this that needs to be limited to assure a humane environment. If you can keep the increment of land development down everything will be OK --in the city at least (in the suburbs it doesnít matter what you do).

    Reasonable basis? Hereís your reasonable basis: there was never any good reason for this provision in the first place.

  4. #4
    Cyburbian The One's avatar
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    Height Stuff

    Some building codes measure height from the midpoint between the eve and peak to the midpoint between the base of home and average grade as measured 10 feet from the base. Important if the home is on a grade as a walk out or built as a B/garden elevation.

    Others measure from base to peak

    Yet others have some other variation on measurement.....

    Multi-Unit buildings tend to require an elevator when more than 3 stories.
    I don't remember seeing too many four story single family homes....other than mansions....I don't think I would like to live in a three story home with basement, too many stairs.... I have seen walk out homes on grade with three primary levels and a basement walk out that look positively UGLY, and will provide an eclipse for the rest of the block for hours....

    I think three level homes serve a purpose for those with strong knees
    "The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness."
    John Kenneth Galbraith

  5. #5

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    I don't want to disagree too seriously. Most specification standards are arbitrary, but there are places where a height limitation preserves things like a capitol building or a church steeple being the dominant feature of an urban scene, and to the better. Height can also be a dominant concern in certain landscape settings, say on a ridgeline, where height will be more important than the footprint in keeping a building from being skylined.

    As for designing cities around fire departments. Where you have an all professional department with extensive training and equipment (and building codes!), sure, they can cope with whatever height you think is necessary. It isn't the same question in a smaller jurisdiction with a smaller budget, and keeping things consistent with emergency service capabilities is a reasonable reason for a height limit, or many other standards, just as long as it isn't taken to extremes.

  6. #6
    Cyburbian
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    Quote Originally posted by Streck
    The reason I ask is that occasionally we have a request for a Variance to exceed that height. I would like to have a reasonable basis for evaluation of the requested Variance, and would like to know if the 35 ft height is still valid for anything.
    /ignored staff advising Board of Appeals mode on// Hmmmm, Variance, so some how the restriction on building height at 35 feet renders the lot unbuildable, yet if you let them have a few more feet the physical limitations on the lot are overcome? Building height would clearly not meet the requirements for a variance under Massachusetts state law which require that the justification be due to a shape, soil or slope condition on the lot.//ignored staff advising Board of Appeals mode off//

    Height is very much a matter of aesthetics. It has been thought of as a way to maintain a traditional New England/Cape Cod feel to the area. We are in the process of adopting (hopefully tonight at Town Meeting) which will increase heights in one part of town to 42 feet. We are instituting design controls to ensure the look everyone feels is important while gaining the third story for residential uses.

    Side note, currently we have no design controls that would require a developer to provide the pitched roofs everyone likes to see, the result is a lot of ugly boxy looking structures. Hopefully we will be able to convince 2/3rds of the town meeting membership that our height proposal with design controls is better than leaving the zoning alone.
    Planning is much like acting, as my old theater professor used to say, "If you sin, sin boldly, only you know if you are ad libbing." I follow this adage almost daily.

  7. #7
    Cyburbian Streck's avatar
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    Thanks for your responses.

    I suspect that the Fire Rating Bureau rating system the key to this height limit.

    How can I, as a Planning Commission member, get info from the Fire Rating Bureau on this?

  8. #8
    Cyburbian H's avatar
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    Where I have worked in Fla that has always been to the highest architectural point.

    ie. top of roof or chimney = 35 feet

  9. #9
    Cyburbian Plus JNA's avatar
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    Ladders on a Engine or Ladder see the list at: http://www.isomitigation.com/fire70.html
    Oddball
    Why don't you knock it off with them negative waves?
    Why don't you dig how beautiful it is out here?
    Why don't you say something righteous and hopeful for a change?
    From Kelly's Heroes (1970)


    Are you sure you're not hurt ?
    No. Just some parts wake up faster than others.
    Broke parts take a little longer, though.
    From Electric Horseman (1979)

  10. #10
    Cyburbian Streck's avatar
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    Thank you for the reference to the ISO FSRS ladder height info.

    How is this related to building heights?

    Is each fire fighting unit required to have one 40 ft ladder, which would mean that it could reach a 35 ft high eave or parapet, and have 4 or 5 ft extention above that level for hand hold depending on angle of ladder?

    How does ISO FSRS relate to Fire Rating Bureau ratings or city requirements?

  11. #11
    Cyburbian Plus JNA's avatar
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    Quote Originally posted by Streck
    How does ISO FSRS relate to Fire Rating Bureau ratings or city requirements?
    Start by reading through the ISO Frequently Asked Questions -

    "How does ISO score a community's fire protection?"
    "What does a community need to be evaluated?"
    "What does ISO evaluate during a survey, and what are the relative weights?"

    At: http://www.isomitigation.com/fire72.html
    Oddball
    Why don't you knock it off with them negative waves?
    Why don't you dig how beautiful it is out here?
    Why don't you say something righteous and hopeful for a change?
    From Kelly's Heroes (1970)


    Are you sure you're not hurt ?
    No. Just some parts wake up faster than others.
    Broke parts take a little longer, though.
    From Electric Horseman (1979)

  12. #12
    Off-topic:
    [RANT] I'm with ablarc: let us not allow fire departments to design our cities. My case: A neo-traditional in-fill subdivision was approved by our PC and City Council on ground that used to be a water works. Eighteen lots adhering to outstanding urban design principals, including small fy setbacks and alley access to 15 of the 18 lots, among other things. The entrance roadway has an unusually wide ROW of 70' in order to develop a real boulevard, designed with mountable curbs so that the fire department could maneuver their equipment around the boulevard. The fire prevention bureau approved the plans.

    Months later, the developer is seeking to have his performance bond released and the fd visits the site and immediately raises concerns that their ladder truck cannot fully deploy its outriggers (18' spread: paved area is 19') if on-street parking is allowed. We specifically discussed this with them and that's how we came up with the odd 19' pavement surface.

    On a freezing, drizzly day I spent an hour with virtually the entire fd and all of its equipment, the developer, city engineer and the developer's architect discussing the site. Our fd has pumpers, quints and two ladders. Their policy is to run at least one piece of each type of equipment to every call (including car wrecks!). So this 35 ton ladder truck must be provided access to every development, no matter what. (Oddly, there are a number of very small streets in the city that have less than 18' of paved surface, impediments at their entrances, and permit on-street parking. They had no comment about those...but all I can think is that 35 ton ladder truck is nothing but an expensive rolling tool box when they go to these sites)

    The fd rep that ok'd the plans says he thought the entire row would be paved. (Hey, jerkoff! How wide do you think an interstate ROW is???). Needless to say, the fd petitioned the Board of Works to limit on-street parking in the subdivision and those gutless wonders agreed. The issue has gone away as only two houses have been built in the subdivision, but as it gets closer to build out, it will raise its head again, I'm sure.

    I'm all for public safety in developing and redeveloping our cities. But let's let the fd fight fires and let the planners do the planning. [/RANT]
    Je suis Charlie

  13. #13
    Cyburbian Streck's avatar
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    Again, thanks for your responses.

    It appears that the ISO section on BCEGS (Building Code Effectiveness Grading Schedule) would be what we need to be familar with in city planning.

    I have asked my Zoning Administrator if he has such a criteria document, and if I may look at it.

    Thanks again.

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