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<br /> eardown. The construction or remodeling of Implications Hinders flexibility in home design,possibly
<br /> limiting floor heights.
<br /> Basement Height. Basements that extend above grade have a
<br /> single-family homes to the maximum allowable s g
<br /> significant visual impact,a typical characteristic of older homes.
<br /> Tsize permitted by land-use and zoning regulation This architectural feature can be displayed using a variety of
<br /> quality materials,including brick or stone. Raised basements
<br /> � - in neighborhoods distinct) characterized b also allow light and air to reach the basement floors ace.
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<br /> Implications.Reducing basement height above grade limits light,
<br /> � - considerably smaller homes. (Glendale, California) perhaps restricting the functional capability of the basement.This
<br /> also removes a unique architectural feature from the home.
<br /> regulations.Zoning requirements that are too permissive can make Setbacks—Corner Side.Ideally,corner lots should be greater in
<br /> ' it economical to tear down smaller,older homes and replace them size and width than interior lots.But in many communities,corner
<br /> with much larger structures.Building envelopes have historically lots tend to be undersized and lack setbacks on each frontage.
<br /> been defined by the setbacks and provide flexibility for siting Consequently,structures that are located close to the road have an
<br /> modest homes.Today,the entirety of the building envelope at the inappropriate and imposing appearance and insufficient room for
<br /> front setback line may be filled with the structure,thus requiring landscaping.Larger setbacks for corner lots and front yard setbacks
<br /> regulations that were previously unnecessary. on each street would solve this problem.
<br /> Implications Creating nonconforming lots and increasing the
<br /> j The Implications of Revised Regulations minimum setback for lots of minimum width could have the
<br /> Regulations that consider the scale of the existing housing stock effect of narrowing a house width and disrupting neighborhood
<br /> can eliminate the incentive for a teardown.The following character.
<br /> section reviews the options for modifying zoning regulations to Setbacks—Side. On lots where the available building
<br /> limit new development and identifies some of the negative envelope.is of proportionate size, increasing the minimum side
<br /> implications that can be associated with the modifications. yard setback would provide additional light and air onto the lot.
<br /> " Zoning District Purpose Statement.The purpose statement Also,a public safety rationale for increased setbacks is to provide
<br /> x. for the zoning ordinance,and for the relevant zoning districts, greater separation between homes in case of fire.
<br /> °i should emphasize the importance of quietness, privacy, Implications Creating nonconforming structures and
<br /> adequate light and air,pedestrian-scale development, attractive minimizing the flexibility in where a house can be placed on the
<br /> streetscape, and neighborliness as the foundation for new site.
<br /> z _ teardown regulations. Floor Area Ratio (FAR).FARs have traditionally been used in
<br /> € Lot Areas and Lot Widths.Increasing the lot size and/or lot nonresidential developments.But as home sizes increased,FARs
<br /> width will not reduce building size,but will reduce the number of were applied in residential districts as well.Developing an FAR for
<br /> lots that can be subdivided,resulting in fewer newer and larger existing residential neighborhoods can be particularly challenging
<br /> homes.This is particularly important when traditional homes are because,unlike nonresidential districts,where a specified numerical
<br /> built on lots substantially larger than allowed in the district. FAR is used,determining the FAR requirement for a residential
<br /> Implications Creation of nonconforming lots and reduction neighborhood includes the use of a formula.
<br /> of the value of larger lots. The following is a sample FAR formula for a district with a
<br /> "H Maximum Building Coverage.The ratio of maximum minimum lot area of 7,500 square feet:
<br /> building square footage to lot size can limit the appearance of
<br /> .T 3,000 square feet+ [(lot area-7,500)x .21
<br /> bulk on the site and maximize the amount of open space, a
<br /> particularly critical element on smaller lots. Lot area
<br /> Implications. Creation of nonconforming structures and This essentially means that a 3,000-square-foot home is
<br /> reduction of the flexibility in house design, forcing homes to be permitted on a minimum 7,500-square-foot lot (0.4 FAR),with
<br /> x""rs taller in order to minimize the house footprint. additional building square footage based on a 0.2 FAR for the
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<br /> Maximum Impervious Surface Coverage.Limiting portion of the lot exceeding 7,500 square feet.
<br /> impervious surface is important for aesthetic reasons, but vital Gross floor area(GFA) must first be determined before
<br /> for surface water runoff and flooding, particularly in areas calculating FAR.The exclusion of certain structural amenities of
<br /> within or near a floodplain. a home from the GFA may encourage home design that will
<br /> Implications.An impervious surface ratio could preclude locating complement neighborhood character. Such amenities could
<br /> a garage at the rear lot line because the additional pavement. include garages behind the front building facade(or toward the
<br /> required to reach such a location would be in excess of the rear portion of the lot where alleys are available),basements that
<br /> impervious surface requirement.Other amenities important to do not exceed a specified height above grade, bay windows,
<br /> - contemporary living,such as patios,might also be prohibited. porches,or attic space. Using FAR bonus provisions to
<br /> :,.. . Height.The height requirement in many older districts is 35 encourage specific structural features is also an option.
<br /> feet, or two and a half to three stories, whichever is less. Implications Creating nonconforming structures and preventing
<br /> However, many new homes are built at 30 feet or less, homebuyers from building a custom-style home;requires
<br /> precluding the need for a radical change in height requirements. substantial staff resources to evaluate plans and determine gross
<br /> Rather,height might be defined in a way that encourages square footage based on ordinance requirements.
<br /> �-'•" pitched instead of flat roofs. Regulating Building Configuration.Some communities have
<br /> a established a setback plane to reduce the looming effect of the
<br /> structure and encourage itched roofs.The setback lane.
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<br /> N. Drew Petterson is Senior Vice President at Thompson Dyke er requires the roof line to recede at a specified angle and height
<br /> Associates, Ltd. in Northbrook, Illinois. above grade, for example:45 degrees at 17 feet above grade.
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