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Thread: Build-out method

  1. #1
         
    Registered
    Apr 2004
    Location
    Richmond, Virginia
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    2

    Build-out method

    Hello Cyburbians,

    I am a policy analyst for a government agency. I want to join one of the forums where I can discuss land use issues, specifically the calculation (estimation) of land supply and demand for land.

    I have a degree in planning, although the nature of my job is not planning; rather, you might say it involves analysis regarding the planning of others.

    In that regard, I recently encountered a situation in which the estimated supply of, and demand for, land available for commercial development in a locality was done in a very simplistic way: Net vacant commercial land divided by historical land consumption pattern equal future commercial land use need.

    I am interested in any critique of this methodology, pros and cons.

    The calculus described above utilized arithmetic and simple projection techniques. It did not take into account the many factors that define reality on the ground.

    No computer-based analysis or modeling of any kind was used, and it is outside the function of this agency’s work to do such.

    I will encounter this same situation again. Frankly, I need to be better prepared, given the technological constraints on my agency.

    So, that is why I would like to discuss this with interested Cyburbians having expertise in land supply and demand theory and methodology.

  2. #2
    Cyburbian Planderella's avatar
    Registered
    Dec 1998
    Location
    NOLA
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    4,468
    Welcome to Cyburbia.

    I'm going to move your thread to another forum where it may generate a better response.
    "A witty woman is a treasure, a witty beauty is a power!"

  3. #3
    Quote Originally posted by Larry
    In that regard, I recently encountered a situation in which the estimated supply of, and demand for, land available for commercial development in a locality was done in a very simplistic way: Net vacant commercial land divided by historical land consumption pattern equal future commercial land use need.
    Larry, welcome.

    I'm not a number cruncher, so take this for what it is worth. The problem I see with this formula is the increasingly smaller number of people per household (such that the historic formula is biased in favor of too great a density) and no consideration (or at least not mentioned) of the by-right zoning of remaining developable ground. What is the per acre density? Will that density develop as zoned or will it be greater or lesser? We ran numbers for our city's 20 year comp plan (which will take us to or very near build out) and the variances were too great to place any real emphasis on them. ( As it has turned out, development has been much higher in commercial than in residential -- precisely the opposite of what we expected.)

    I'm sorry that I can't point you in a better direction. Hope this little bit helps.
    Je suis Charlie

  4. #4
    Cyburbian Doitnow!!'s avatar
    Registered
    Dec 2003
    Location
    India
    Posts
    499

    Indian Perspective

    Hi and Welcome Harry!
    I can't really help you in this Build Out Analysis you speak off. It seems to be an American Exercise. Buyt I can give my perspective ...

    From what little I understand of this method from the 'Cyburbian Knowledge Pool', this kind of exercise, atleast I have not heard of anyone who does a detailed build out analysis out here.
    But this argument about densities. Yes.
    We stopped using the density as a major factor for planning. I know ti may cause an uproar in the planning community.
    But by doing structure plans which would be flexible to take in a drastic change in the uncertain future( this uncertain future with Technology being a major factor for making it uncertain becomes a major reason for failure of perpspective plans) we are willing to take that uncertainty as pressure on infrastructure. Therefore we plan heavily for future growth in infrastructure( but ensure we dont overplan and overprovide right now).

    Most planned plans in our cities have not been able to stop the proliferation of commercial areas into supposedly non commercial areas. The Master Plan and the Comprehensive Plans have failed in India. I'm not blaming the planners for it at all as I am aware that Plans are good only if they are enforced and enforcement is a complicated issue in India.

    But for a population projections we use a range of 4 to 5 persons per household( household is different from a house).YEs we do the population projections using very simple means. NO longer are complicated methods being used.

    This with a proposed mix of land use and building types as per national and state policy( there are reserved quantities for the economically weaker section-EWS Housing) and gets us a broad area requirement. THis figure is then divided by the total proposed population and the resulting density is crosschecked whether its looks good or not.

    SInce this method was primarily used by the government to plan and provide and now the supply of land as well as housing is with the private sector the mothod has been reversed.

    I know there are huge loopholes in the method which I have only briefly described above, but this is what it looks like.

    I have spotted other threads in which this Build Out thing you speak of is covered. I'm sure you will get useful responses from your american friends.

    Off Topic:
    Komitet Gosidartsvinoy Bezopasznosty
    Slowly as I get aware of your Russian link Gedunker, I would like to tell you that this term was one of my favourites when it came to quiz competitions.
    I was one of the very few who could answer what KGB stands for or for that matter MiG( Mikoyan Grevich- correct me if I am wrong). This answer gave me the edge to win some very closely fought quizzes. I still indulge in the activity and never miss the interesting ones.
    Last edited by Doitnow!!; 23 Apr 2004 at 9:49 AM.
    "I do not fear computers. I fear the lack of them".
    -Isaac Asimov

  5. #5

    In that regard, I recently encountered a situation in which the estimated supply of, and demand for, land available for commercial development in a locality was done in a very simplistic way: Net vacant commercial land divided by historical land consumption pattern equal future commercial land use need.
    What do you mean by "a locality" in your original post? Does it mean a municipality or a development site? That is, are you commenting on comprehensive plans and their background studies prepared by other municipalities or agencies; or are you commenting on commercial rezoning applications?

    Scale is an important consideration here. Unless your work deals with comnprehensive plans over large areas, it is really not worth spending the time on anything other than using simple analyses as you had described.

    In our planning works with my communicty, we do not usually use anything other than simple analysis on commercial land requirement. There was one instance, however, that I used the "Market Study" approach to estimate retail commercial land requirements. That was done for a settlement of 20,000 population.

    Basially the method was to estimate the retail sales potential for that community. Convert that into square footage using per footage sales figures. Then deduct the existing retail commercial sqaure footage of that community from the estimated total. If there is a significant difference, then convert that to land area.

    But as you can see, it is quite time consuming unless you have a master spreadsheet already set up. It also require a lot of raw data and making many assumptions along the way. The end result may not necessarily be more accurate than using a simple line projection method.

    As a test, you can try both methods on the same situation.
    Last edited by Planderella; 26 Apr 2004 at 12:32 PM. Reason: Quote tags fixed

  6. #6
         
    Registered
    Apr 2004
    Location
    Richmond, Virginia
    Posts
    2

    Build-out method

    Hi, thanks for responding.

    By locality I am speaking of a municipality, specifically a small town.

    To expand on this a little, a consultant who was hired to rebut the town's assertion that it needed more land for commercial development successfully used the method to defeat the town’s intentions.

    Because the region had seen little growth in recent years, he used historical land absorption data. Since the town was largely residential, with a small amount of commercial, he used that as a factor. By multiplying all the net available land in the town by the percentage of development that was commercial, he got his total demand for net commercial land. When he divided that “demand” by the historical land absorption rate, he got a “supply” of commercial land that, by his accounting, would last the town deep into the century.

    My concern is that little or no consideration was made for parcel size, soil conditions, zoning, adjacent uses, transportation issues; just a whole host of factors that would render a lump-sum acreage of land supply invalid (in my view) as an accurate accounting of available land suited for commercial development.

    Needless to say, the town was not awarded the land, in part because the supply-demand methodology we’re discussing was given considerable credence. Again, I need to pick this apart, get to its pro and cons as a useful methodology. I used the term “build-out”; I’m not sure that is the right terminology for this.



    What do you mean by "a locality" in your original post? Does it mean a municipality or a development site? That is, are you commenting on comprehensive plans and their background studies prepared by other municipalities or agencies; or are you commenting on commercial rezoning applications?

    Scale is an important consideration here. Unless your work deals with comnprehensive plans over large areas, it is really not worth spending the time on anything other than using simple analyses as you had described.

    In our planning works with my communicty, we do not usually use anything other than simple analysis on commercial land requirement. There was one instance, however, that I used the "Market Study" approach to estimate retail commercial land requirements. That was done for a settlement of 20,000 population.

    Basially the method was to estimate the retail sales potential for that community. Convert that into square footage using per footage sales figures. Then deduct the existing retail commercial sqaure footage of that community from the estimated total. If there is a significant difference, then convert that to land area.

    But as you can see, it is quite time consuming unless you have a master spreadsheet already set up. It also require a lot of raw data and making many assumptions along the way. The end result may not necessarily be more accurate than using a simple line projection method.

    As a test, you can try both methods on the same situation.
    Last edited by Planderella; 26 Apr 2004 at 12:32 PM. Reason: Quote tags fixed

  7. #7
    Quote Originally posted by Larry
    My concern is that little or no consideration was made for parcel size, soil conditions, zoning, adjacent uses, transportation issues; just a whole host of factors that would render a lump-sum acreage of land supply invalid (in my view) as an accurate accounting of available land suited for commercial development.

    In my experience, I have never come across any reports that carry out the kind of detailed parcel by parcel analysis that you described in support of any municipal-wide plans. Certainly, factors such as soil conditions are not considered except at the very gross level---such as the avoidance of the floodplain, steep slopes etc. Those environmental factors should have been considered in the original designation and zoning of lands in your existing offcial plan and zoning by-law.

    Most commercial or indistrial land requirement analyses are done at the very gross level. In particular, most industrial land and office space demand analyses are done by using historic absoption rates. Only in retail space analyses that the "Market Study" approach that I described previously are sometimes used.

    In your case, I don't see how you could rebut the opponent's analysis without generating your own numbers, either using the same method or an alternate method.

    For a small town with a historically slow growth rate, perhaps your opponent's conclusions are correct. Short of having some wildcards such as the development of a new Super WalMart or similar big box developments, I can't see how a small town can support substantial commercial expansion. Is you city located next to a major urban center? If so, the WalMart wildcard scenario might happen. But even then, that would still be an assumption for one of several potential scenarios. You cannot support the allocation of commercial land based on such a scenario alone.

  8. #8

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