Green Laws And

  Community Design

  STUDY GUIDE

Pennsylvania Shade Tree Law, 1700

........”every owner or inhabitant of any and every house in Philadelphia, Newcastle and Chester shall plant one or more trees, viz., pines, un-bearing  mulberries, water poplars, lime or other shady and wholesome trees before the door of his, her or their house and houses, not exceeding eight feet from the front of the house, and preserve the same to the end that the said town may be well shaded from  the violence of the sun in the heat of summer and thereby be rendered more healthy.........

Reilly 1973

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Figure  3-1: Early Municipal Green Law, The Pennsylvania Shade Tree law of 1700

 

Green Laws Designing With Community Landscape Laws

Seminar Notes

 

*** Introduction *** Study Guide *** Part I - Problems Green Laws Solve *** Part II - What is a Landscape Code ***

*** Part III - Geography of a Development Site ***Part IV - Visual Effects of Landscape Codes ***

*** Part V - Landscape Codes, Protect, Preserve, and Promote Nature in the City ***

*** Review Questions *** Landscape Vocabulary *** Administrative Terminology ***

*** Review Questions & Self Study Exam ***

*Student Questions*

*Professional Level Questions*

 

 

        Introduction:

 

Landscape laws can be traced as far back as the Pennsylvania Shade Tree Law of 1700.  That law, cited above, was drafted by the proprietor of a large tract of land in what is now eastern Pennsylvania. Wm. Penn drafted that law to set standards for landscaping and tree planting in some of the early settlements in the vicinity of Philadelphia. Penn set design standards for the type of plant material to be planted, indicated where it was to be planted and stated his purpose for the planting of such material.  His law when drafted, was not only an early landscape law, it really was an ancestor of contemporary zoning as we it know it today.  Zoning then and now, set standards for the development of land and urban communities. Zoning was created along with the police power to enforce it to ensure that communities developed according to standards that the majority of citizens agreed upon. Over the years, zoning has been reaffirmed by legislative action (Zoning Enabling Act 1926)  and court decisions (San Francisco v. Yick Yo and Hang Kie, 1886, Euclid v. Ambler Realty, 1926, Ayres v. City Council of Los Angeles, 1949, Berman v. Parker, 1954).

 

Common zoning standards accepted by everyone today include limitations, requirements and standards. Examples of these are zoning regulations that set density standards, permitted lot sizes, allowable land  uses, minimum frontages, setbacks, opens space. Within zoned communities, zoning districts are created to promote compatible land use patterns within the city limits. Zoning districts may establish site development regulations and performance standards appropriate to the purposes and the uses allowed in each district. (City of Austin, Texas). Furthermore, specific site development regulations which protect, preserve and re-build nature and natural systems may apply to zoning districts or special use districts such as  special overlay districts, mixed use development districts, conservation subdivisions, sensitive natural habitat districts, historic districts and special areas used as buffers, corridors, growth management boundaries and preserved natural habitat districts.

 

In recent years, zoning has become the tool for directing urban development.  Landscape codes and tree laws are in the forefront of contemporary development regulations. In the future, landscapes laws may very well be transformed into urban design development standards that not only set standards for post construction landscaping, tree preservation, buffering, screening, parking lot development and habitat improvement, but design standards for public architecture, special use area commercial districts, parks, roadway edges, public preserves, natural storm water collection systems and community forests.

 

The slide show part of this seminar has been prepared to help you understand how landscape laws and zoning influence community design. The following illustrations, photographs, texts and drawings will demonstrate some basic concepts about landscape laws. The following images have been prepared to:

 

a.       Provide a collection of photographs depicting problems of community design that can be remedied with the use of trees, shrubs, ground covers and other living vegetation and closely related landscape structures.

b.      Provide a series of drawings that depict a typical commercial construction site and how it might be enhanced through habitat preservation, tree protection and general site landscaping.

c.       Provide a collection of photos showing the visual effects of landscape law in communities that have adapted landscape codes and tree laws.

d.      Aid readers in understanding design components, technical standards and the vocabulary of municipal landscape law.

e.       Offer some on-line internet links to sources of related information and technical knowledge on the subject of tree and landscape codes.

 

The seminar show has been designed in three major parts, and two minor parts. Each major part focuses on subject mater that is critical to the understanding of this field of study. Each of the major parts presents subject matter, illustrations, and text. Each part can take up to forty five (45) minutes of self study time when you use the Seminar Notes which can be downloaded from our web site, www.greenlaws.lsu.edu.  The three major parts and the two minor parts of this program  include;

 

In the first section of the show, Part One, “Problems Green Laws Solve,” common problems, which landscape codes and good landscape design can solve, are showcased. You will find out about the problems caused by excess paving, lack of shading, improper screening, degradation of natural habitats and wide spread urban tree removal.

 

The section “What is a Landscape Code” Part Two of the show, sets forth the methodology by which communities build and develop.   You will learn about the role of government in community development, as well as what architects, engineers, and landscape architects do. The role of the landscape code, zoning ordinance, and building code are mentioned, and you are introduced to the vocabulary of design components.  These are the parts of a development site that make up the “geography” of urban lots and building sites.

 

Section three of the disk, Part Three, “ The Geography of a Development Site” explains the art and or science of site development. A case study of a small urban commercial site is presented to display the most common parts of a development site that fall under the purview of landscape codes. You will learn about street tree planting areas, street yards, street walls, parking lot screen, buffers, vehicular use areas, VUA interiors, and habitat preservation zones. You will learn what they are and by what technical standards they are judged.

 

In addition, you will be briefly introduced to some leading edge concepts which are not fully integrated into very many landscape codes at this time but hold our promise for future inclusion.  These items include Xeriscape ™ design principles and water conservation, land clearing, habitat preservation, on site storm water management micro-retention techniques and the science of green parking lot design and tree banking.

 

In  Part Four, of the program,   “The Visual Effects of Landscape Codes,” takes a look at the visual effects of  landscape law as they are seen within communities that have enacted such environmental legislation.  This part shows examples of how landscape laws influence site clearing to the design of vehicular use area interiors. You will be taken on a tour of communities in the United States where you will see examples of good community design which are primarily the result of community landscape laws. These slides will inspire you to see the green visual effects that landscape laws bring to community design.

 

In the final segment of the program, Part Five, you are provided  resources that may prove helpful in your independent study of green laws. You will find here reference to the LSU Research Web Site, that we call the LSU Green Laws web site. It’s url is www.greenlaws.lsu.edu.  There is lots of information here on landscape laws and tree management laws.  You will also find in this part of the program reference to the book Abbey, D.G. Buck, U.S. Landscape Ordinances, John Wiley, NYNY, 1998. This book contains very detailed information about landscape laws in over three hundred communities. The book can be ordered at www.wiley.com.  Another resource which is available is the CD Green Laws and Community Design which was prepared by LSU for the Louisiana Department of Agriculture & Forestry with support from the Louisiana Nursery and Landscape Association and Live Oak Gardens Nursery LTD of New Iberia, Louisiana.  The CD is free for the asking by writing the Louisiana Department of Agriculture & Forestry.

 

An finally, you will find a listing of credits for the design, writing and production of this program. You will find out about the LSU Landscape Ordinance Research Project and how it has spent years studying green laws.  You will see the names of our students and research sponsors of whom we are grateful for in their contribution to this educational program. We appreciate the use photographs and drawings which are credited to various artists throughout the program.

 

The research that makes this program available has been  supported in part with a USDA, Forest Service, Urban And Community Forestry Grant, administered by the  Louisiana Department of Agriculture & Forestry

P.O. Box 1628, Baton Rouge, LA 70821-1628  225.925.4500

 

 

By the end of the show, you will realize that this seminar is about nature in the city. You will have learned what landscape architects, landscape administrators, urban foresters, arborists, horticulturalists, and landscape contractors can do to protect, preserve, and promote the green infrastructure that really improves our quality of life. 

 

Good community design means we must keep nature in the city. Landscape codes and tree law are the proper way to go about doing that. Communities across America should enact minimal landscape laws that will protect significant trees and ensure a minimal amount of landscaped open space on each development site.

 

At the end of these notes you will find a comprehensive landscape code vocabulary and definitions, which will assist you in understanding many of the words or meanings expressed in this slide show.  All of the definitions are derived from public landscape laws within the United States. Two classes of definitions are presented.  Those that deal directly with development site, (The Geography of a Development Site), and those that define administrative terms associated with landscape laws. You will also find a self study examination which can be used to quiz yourself on the knowledge contained within these materials.  There are questions for students as well as questions for seasoned administrators, consultants and motivated citizens.

Prof. Buck Abbey, ASLA

Louisiana State University

Orange Beach, Alabama

 

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Self Study Guide

 

The following seminar notes have been written to enhance ones understanding of each slide presented in the slide show.  Each of the notes below will offer background material that will increase a student’s ability to understand and communicate the ideas and issues shown in each of the 84 slides contained within the slide show.  The slides have been selected to visually convey the idea being discussed. Notes have been added to each slide which focus on the issue being presented

 

 

1. (Green Laws And Community Design) Title Slide

Welcome to this program prepared for the American Society of Landscape Architects Desktop Seminar Series with assistance from the  State of Louisiana, Department of Agriculture And Forestry and with partial funding by an Urban And Community Forestry grant from the USDA.  We are pleased to teach you about landscape laws that we call g r e e n   l a w s.

 

 

 

 

 

2. (Course Description)

 

•Course Description: Landscape laws, tree laws and land alteration codes are springing up across the country as a method of protecting, preserving or rebuilding nature in the city. Landscape codes are actually an extension of zoning law and are seen as tools to make cities livable. Landscape codes and tree preservation strategies are also seen to be a smart growth strategy that can enhance development while protecting nature. Landscape architects, planners, urban foresters arborists, landscape contractors and citizen environmental groups, the thin green line protecting nature in the city, must work together in understanding green laws and help elected officials, citizen zoning commissioners, tree boards and landscape commissions understand the science and art behind community landscape laws

.

•These laws have certain design components and technical requirements that professional landscape architects, architects and engineers must comply with under contemporary building regulations in some of America's towns and cities. In turn, compliance with theses laws, creative interpretation of their provisions, is imparting a visual image that is "greening up" neighborhoods and communities and leading to a better understanding of urban design

 

•Landscape law design components such as tree preservation, street wall plantings, parking lot screens and vehicular use area configurations and street yard plantings are all part of written landscape laws. These are complex terms that relate not only to the law, but to the design of physical landscape. These components all have physical descriptions as well as visual meaning. They are all composed of an ordered assembly of trees, shrubs, ground covers and landscape structures.

 

Understanding the design components that make up a landscape law is the key to understanding the visual structure of a landscape designed as a result of the words contained within the law.

 

 

3. (Students)

•Please register for this course.  To get this class off and running as an on-line collaboration between the instructor Prof. Buck Abbey, and the student seminar taker, please take a few moments to e-mail the following information to the instructor. 

•

•During live programs students will be acknowledged as the “student from Jackson, Michigan” or “the student from Boston” rather than by name. This will protect your privacy and allow other students in the live sessions to feel like they know the other students in the class on a personal basis..

•For Archived presentations just go ahead and e-mail the information to the instructor so that he may contact you after you have taken the Desktop Seminar to see if you have any specific questions you seek answers to.

 

•Name__________________________

Town where seminar is being taken__________________

•Mailing Address_____________________  ____________  _________ 

•E-mail    ____________________________

 

 

 

 

 

4. (Working With Nature In The City)

 

Green Laws include various kinds of municipal ordinances, laws and landscape codes that deal with nature in the city. Landscape Architects are among a small group of people who look out for nature in the city. It is the responsibility of Landscape Architects to preserve, protect and rebuild nature in American towns and cities.

 

It is through municipal tree and landscape law that developers and designers work with nature in the urban environment.  Who looks out for nature in your city?  Is it the Mayor? The Town Council? Director of Public Works? The developers, designers, bankers or real estate industry? Or the laws, codes and ordinances of the city which deal with nature?  It should be all of these, in a community that seeks good design.

 

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 Part One- Problems Green Laws Solve, Title Slide

 

Communities are always built incrementally following procedures that are sometime mystifying and bewildering at best, other times, confusing and misunderstood at the worst.  Often times, community development is market place driven. Other times it is driven by opportunity or chance.  Sometimes the law controls it, other times, designers like architects, engineers, landscape architects, builders, and developers, are responsible for the way cities evolve. Their creative ideas build cities. 

 

 

No matter what form or evolution a community takes in its development, mistakes are made which lead to poor community design. Lets take a look at some common mistakes, misjudgments, and awkward situations.  All of which can be remedied to some extent by green laws.

 

 

4. How We Build.  

 

Green Laws, in the form of landscape codes, tree ordinances or land alteration codes solve problems of community design. They assist nature in the city by helping developers build greener communities and helping communities maintain their contact with natural systems. Landscape architects, landscape contractors, landscape maintenance companies, horticulturists, irrigation contractors and arborists all serve nature and are agents who work to ensure that nature’s vegetation, water, soils, climate and wildlife remain in the city to serve the needs of city dwellers.

 

 

6.

 (How We Build)

Good community design is defined in several ways.  For this discussion we will use the definition that good “community design is a balanced approach to development that allows nature to play a significant role in the community and a significant role in each development site within that community. Good community design will allow nature to perform a number of environmental services as well as make the community more interesting from a visual and physical point of view. Good community design means retaining the urban forest canopy, reducing on site run off, screening objectionable views, minimizing the importance of the automobile and its parking areas and providing habitat for urban wild life. Further, good community design brings to the community the lines, colors, texture, forms, and patterns created by the careful composition of landscape design elements that have flowers, fruits, interesting bark patterns, and assorted leaf characteristics.  Nature in the city is one measure of good community design.”

 

 

 

 

7. (Why Landscape Regulations?)

 

To help the city grow in an orderly manner and to protect the property values of land owners there are certain landscape regulations that are accepted by the city and the development community.  Landscape regulations, better called landscape design standards, help provide uniformity with creativity in the development of land. There are several common problems that landscape standards are often  written into a community landscape to solve.  Common Problems to site planning include……..

the following slides)

 

 

Sites Without Trees

Land Clearing

Tree Removal

The View From the Road

Paving To The Street

Street Edge

Street Yard

Street Walls

Building Entries

Parking Lot Design

VUA Interiors

Interior Island Plantings

VUA Walkways

VUA Screening

Storm Water Run Off

Yard Buffering

Trash Screening

 

 

 

8. (Land Clearing)

Development can take place in such a manner that some trees and natural places can be preserved on every development site. At the very least, natural areas which are modified or removed can at least be recreated or rebuilt through thoughtful landscape design. Land clearing is one of the most destructive forces turned loose on the natural world. Uncontrolled land clearing destroys vegetation, relocates species, erodes, compacts or buries fertile soils, changes micro-climate and can alter natural drainage patterns and water table levels.

 

It is good design to save patches of native ground and groves of existing trees that are special or unique natural habitats within the city.

 

 

 

9. (Tree Removal)

Land clearing and tree removal are not the same activity.  Land clearing is often done to change grades, provide for drainage and build site facilities like buildings and parking lots. Tree removal is often done just to prepare the site for sale or development.  With proper site planning and design, it is possible to retain significant groves of trees and natural habitat while still grading the site for construction, drainage and use.

 

 

 

 

 

 

10. (Hatracking And Planting)

Good community design means the proper selection, planting, maintenance and care of plant materials, Trees, should be selected for their varied characteristics as well as for the specific site in which they are to grow. Hatracking as seen in this view, is poor arboricultural services. In fact some would call this “arboriculture malpractice.”  Professionally trained and licensed ISA (International Society of Arborist) Arborists’ would never hatrack trees such as seen here. 

 

 

 

 

 

Good community design means the proper selection, planting and care of plant materials.

Plants, especially trees, should be selected for their varied characteristics as well as for the specific site in which they are to grow.  Selecting plant materials to grow below overhead power lines is particularly daunting. The wrong plant selected, will result in extra maintenance by the holder of the utility servitude. Utilities often occur near plantings so both must be considered together.

 

 

 

In some communities landscape codes may include pruning and tree care specifications or may make reference to national pruning and tree care specifications. Hatracking, as you see it here, is outlawed in the landscape codes of many communities. 

 

Also, within the landscape codes you will find standards and specification for plant material.  Often specifications will be given for size, quality, spacing, installation, staking, mulching, fertilizing and watering. Some communities refer to established horticulture specifications such as American Standards for Nursery Stock ANSI Z60-1980 or latest edition in their landscape code. 

 

Many communities prepare lists of approved plant materials and only these plant materials may be used for credits toward landscape requirements. Some communities prepare lists of ‘outlaw plants,’ usually aggressive non-native exotic or plants and trees that are not cold hardy.   Outlaw plants are not wanted in some communities.

 

Many communities provide “credits” for any trees that are preserved on site. This makes good sense especially if the trees that are preserved, are inventoried, analyzed for health and condition, and can be preserved in groves or groupings of trees.

 

According to the Palo Alto, California tree ordinance, the municipal arborist can issue tickets, a form of ‘administrative procedure,’ for tree ordinance violations. The city arborist is authorized in the Code to establish specific technical regulations, standards and specifications necessary to implement the Ordinance and provide guidance for the required or recommended care, removal and replacement of regulated trees. Their ordinance leads to a better urban forest canopy and more professional and better trained community of commercial tree arborists.

 

 

 

11. (The View From the Road)

 

The primary reason to enact a landscape code is to preserve the view from the public right-of-way.  A roadway without trees is a barren roadway that can be cluttered up by utility poles, driveway cuts, business signs, traffic signs, billboards, street side parking areas, water tanks, commercial buildings and overhead power lines.  Landscape codes also set standards for the design of private properties fronting roadways. The way people develop roadway frontage heavily influence the view from the road. It is not un-common for landscape codes to require parking lot screening and plantings in the street yard of a building site.

 

 

The public road is an American institution. Roads organize our communities and are our access routes from home to work, and from home to play. They are corridors of public safety and are used for public services.

 

Commercial establishments prefer to locate along heavily traveled roadways as they feel that highly traveled roads bring in more customers. To some extent they are correct.

 

 

But the view from the road is also important.

 

A roadway without trees is a lifeless cluttered roadway.  Roadways are often cluttered with utility poles, driveway cuts, business signs, traffic signs, billboards, street side parking areas, water tanks, commercial buildings, and overhead power lines. When you throw in moving cars, one turning left, the other right, a pick-up truck darting here an SUV darting there, the scene becomes too much to understand.  So much variety of shape, form, color, texture, and motion the scene is next to impossible to understand. We see only a fraction of what is there.

 

 

Cluttered road edges are not only overly complex visual scenes, unattractive, and hard to understand, they are potentially unsafe to a motoring public.

In this scene, compare the visual condition of the commercial side of the roadway to the right with the residential side of the roadway to the left. They are two completely different driving experiences.

 

 

Communities are finding that landscape codes can be used to ensure that street trees are planted along streets. Plantings along the edge of the public right of way will unify the street, focus attention on driving, and cut away many of the distractions caused by excess signage and street clutter.   Plantings, of course, need to be carefully selected. A mix of deciduous, evergreen, flowering, and fruiting varieties can thrive in poor growing conditions, take the abuse of neglect and will grow without causing damage to overhead wires and below ground utilities. 

 

Selecting the right combination of trees and shrubs is a difficult challenge. Some community landscape codes specify recommended species of trees that will grow well in a roadside environment.

 

Landscape codes also set standards for the design of private properties fronting roadway. The ways people develop roadway frontage heavily influence the view from the road. It is common for landscape codes to require parking lot screening and plantings in the street yard of a building site.

 

 

 

12. (Urban Heat Islands)

 

 

Sites without trees in the hot sunny South and Southwest and are not only hot and uncomfortable but are visually unpleasing and often lacking in scale. Parking lots like this one are hot, humid and un-attractive. Temperatures within cars often reach 150 degrees. Children and pets can die if left in cars in un-shaded parking lots.

 

Why do you suppose the cars in the far center are parking in the shade of the shopping center sign? Commercial developers for years have routinely removed trees and vegetation and built retail and commercial establishments totally lacking any sense of landscape design.  They obviously do not understand the urban heat island effect.

 

According to researchers at U.C. Davis, trees in parking lots and business districts provide many environmental services.  For instance, trees in parking lots tons of CO2 from the atmosphere per year (McPherson et. al., 1999).   Their studies have shown that 100 trees remove 1000 lbs. of pollutants per year, worth about $4500 in emission credits (in the Central Valley of California) (McPherson et. al., 1999). Trees in parking areas are one of the most cost effective means of reducing the ‘urban heat island effect’ caused by vast areas of paving within our cities. One study indicates that trees lower temperatures .5 - 1.5° C and reduce surface asphalt temperatures by 36°F and vehicle interior temperatures by 47°F. Cooler temperatures reduce ozone concentrations and lower hydrocarbon emission from parked cars.

 

 

 

 

 

Some communities are making parking lots tree friendly and writing ordinances that require shade in parking lots.  Codes in Raliegh, North Carolina, Sacramento, California,  Atlanta, Georgia and San Antonio, Texas are writing special provisions to require fifty (50) percent shading within fifteen (15) years. Austin, Texas is  rewriting their landscape and tree laws to provide more shade as a means of reducing the “urban heat island effect” arising from their built up area. Gwinnett County, Georgia has a very tough tree preservation ordinance that requires preservation of many trees and replacement of others.  Baton Rouge, Louisiana drafted a “native tree preservation clause” to be inserted within their landscape ordinance. The concept was to require that all native trees of a certain size be replaced following removal for construction on an ‘inch by inch basis” up to a maximum number of caliper inches equal to 258 of native trees per acre based upon a standard calculated by testing native stands of forest in the community to determine the average number of caliper inches per acre.  The proposal which would have rebuilt the urban forest around development rather than build community development within the urban forest got “watered down” during the three year process that led to Metro-Council approval on July 16th, 2003 ad public ordinance no. 12692. The native tree preservation proposal was passed but in a much less comprehensive manner.

 

 

When trees are removed, the sun bakes the land. Shady parking lots absorb the sun, provide cooling shade, reduce ambient temperatures, cool parked cars, filter pollutants from the air and make a much better looking city. Large expanses of concrete and asphalt raise ambient air temperatures and make city living more uncomfortable, especially in the South and Southwest.

and and

 

Commercial developers for years have routinely removed trees and vegetation and build retail and commercial establishments totally lacking any sense of landscape design.  In this scene there are no trees within the commercial shopping center. The trees seen in the rear of the view are in a residential neighborhood beyond. It begs the question.  If we enjoy trees so much in our neighborhoods, why do we not like trees, shrubs, ground covers and flowers within our commercial retail establishments?  The fact is, we do and business is known to prosper whenever landscape materials are used in abundance to enhance the shopping environment.  Landscape materials provide shade, color and texture and invite urban wildlife to join into the scene.

 

In recent years, landscape codes have been used to help the development community find better ways of building commercial landscapes. Landscapes that are attractive to shoppers and neighbors alike. Collier County/Naples Florida for instance has enacted parking lot tree planting requirements for all commercial developments.  In shopping centers, not only do they require parking lot tree plantings, but they require that shopping centers have courtyards which are planted and provided benches and other open space amenities.

 

Even filling stations in this Southwest Florida community must be improved by landscaping.  You would never see the filling station in the rear of this slide in Collier County, Florida. It would be screened with trees, shrubs and earth berms.

 

 

13. (Street Edge)

Street edges are owned by the city and should be carefully controlled as to size and access points. Curb cuts should be restricted and reduced in number allowing more space for street tree plantings and below ground utilities. Minimum curb cuts are desirable along public street and all curb cuts should be properly sized. Not only is using interconnected parking lots to minimize curb cuts good design, it is a smart way to grow as it controls traffic flow and movement in the development. Some communities require the developer of property frontage to plant the street edge with street trees. Additionally, the developer or private property owner fronting a public street is often required to maintain trees, shrubs and lawns which may be planted in the space at the edge of public street.

 

The view you see here of a street edge with no planting is not good design and would never be allowed in many American communities. Landscape codes often require plantings along public streets.

 

Paving to the street with a continuous curb cut is not allowed in smart communities.  Not only is it unsafe for drivers and people who park cars, it is unsightly to push a building to the front property line.  “Street tree planting areas,”  “buffer standards” and “street yard planting areas” were created to prevent strip developments where all businesses look the same and where no physical separation between adjacent land uses or public streets exists.

 

 

 

14. (Street Yard)

The area behind the street right-of-way, and, in front of any building on private property is known as the street yard. Street yard design standards prevent property owners from paving to the property lines as seen in this photo. They often  require a minimum number of shade trees, shrubs and ground covers

 

Street edges and street yards can be designed and planted to help reduce roadside distraction and clutter thereby making public roadways safer places to travel. Exceptions are often granted to businesses that use their street yards as a sales display area. But even though they may need to apply for a zoning variance.

 

 

Community landscape codes will often set aside ten (10) to twenty (20) percent of the site for landscaping and open space.  Much of this open space occurs in the street yard, which is space between the front property line and the building wall. Sometimes the street yard planting area is attached to the front property line, other times it is allowed to ‘float,’ or to be located any where within the space between the street-side building wall and the front property line.

 

 

 

15. (Yard Buffering)

The third most common reason to enact a community landscape code is to provide buffers between properties, specially those properties of differing land use. 

 

 

Large amounts of land within cities occur along property lines and often this land serves no real purpose.  Side and rear buffers between neighbors make better neighbors and a more orderly neighborhood. Buffering of contrasting land uses makes a more visually compatible city.  Rear and side buffers are often planted with layered shrub masses, ground covers and trees and act as natural areas for urban wildlife like birds, rabbits, squirrels, raccoon and beneficial insects. Naturalized buffers become wildlife habitat and provide cover and pathways through the city for small urban creatures. Care should be taken to insure that pedestrian linkages between land uses is not blocked by these vegetated buffers.

 

 

16. (Building Entries and Street Walls)

As previously stated, paving from the property line to the wall of a building is not good design. Many communities require a strip of planting to occur between parking lots and buildings, especially those walls that face public streets. Plantings to separate building from parking soften the harshness of buildings and improve both the safety and the pedestrian experience of parking lots.

 

 

Parking lots that are paved right up to the door of the building are not pedestrian friendly, nor are they safe. Street wall planting design prevents building the parking lot to the building wall. Planting between the parking lot and the building and adding walkways, waiting areas, fountains or sculpture increases the quality of the pedestrian experience and enhances safety. Many communities who favor good design do not allow paving up to the foundation of the building. It is interesting to note that the concrete bollards have been added to keep cars from crashing into the building.

 

 

17. (A Sea of Parking)

The second most common issues addressed in a community landscape code is car storage. 

 

Studies at the Center For Urban Horticulture at the University of Washington landscaped parking areas are good for business. In one study the researcher reports that shoppers shop more often and will shop for longer periods of time in well-landscaped business districts. Shoppers who choose well landscaped sites are willing to pay more for parking, and up to 12% more for goods and services (Wolf, 1999).

 

 

 

Eighty to ninety percent of the demand for parking is met with surface parking lots. Some have estimated that surface parking often utilizes two or three times the amount of floor space used in commercial buildings.  A ten thousand square foot commercial office building is likely to consume twelve thousand square feet of parking ( 1 space for every 250 square feet).  That would be enough ground space to store forty (40) parked vehicles. 

 

The supermarket on the corner that has one hundred and fifty thousand (150,000)square  feet under roof, would require seven hundred and fifty (750) parking spaces consuming two hundred twenty-five thousand (225,000) square feet (1 space for every 200 square feet) or approximately five (5) acres of land. 

 

 

A regional shopping mall of two (2) million square feet of retail space would require parking for sixty six hundred cars taking up almost fifty acres of land (1 space per 300 square feet). That is a lot of land, those are a lot of cars.

 

 

Obviously, the more intense the land use, the more cars will need to be stored and more land that must be set aside for car storage. In the past it was common practice to just cover the fifty acres with concrete or asphalt. The parking lot was one vast expanse of concrete that became a tremendous solar collector and covered an area large enough to drain five million gallons of water in a twenty four hour rainstorm.  At the rate of  0.15 cfs/acre per day, five million gallons of run off, is a lot of water to drain. 

 

In recent years, people want parking areas to be cooler, more compact, partially screened from public streets, and broken up with the use of landscape plantings. Some communities require buffers between parking lots while other communities require that parking areas be located behind commercial buildings and not in front of them.  Still other communities are finding it smart to organize parking by with ‘car sorting’ strategies, use porous paving to reduce surface run-off and planting large canopy trees to shade, cool and filter the air in parking areas.  Additionally, pedestrians, and pedestrian access are becoming more important to the design of the parking lot than the car.

 

 

Landscape codes set new design standards for parking lot design.

 

18. (Concrete Sites)

Studies at the Center For Urban Horticulture at the University of Washington confirm that paving increases urban temperatures. One study indicated that dark pavements such as asphalt generate the most heat gain. They estimate solar reflectivity of only 5% to 10% while lighter colored paving surfaces such as concrete have solar reflectance rates of 25% or higher. (Wolfe 2003)

 

Heat build up lingers in the city hours after the sun goes down which requires air-conditioned cooling for urban buildings long into the night. In winter months, in the north this heat build up can be beneficial. Parking lot trees and shrubs that are deciduous should be planted in parts of the country where winter heat build up is welcome.

 

 

 

 

Many developers feel that paving from lot line to lot line reduces the amount of site maintenance that is necessary to keep a business up and running.

 

They do not want nature or natural elements on the site and do not want to maintain grass, prune shrubs or keep planting beds mulched. They are not concerned with drainage and they do not care about the aesthetic qualities that natural elements bring to a site. 

 

What developers who think like this are really doing is kicking nature out. They are kicking out trees, wildlife, and the positive benefits of them, such as the cooling effects that trees bring to development site. They do not recognize the beneficial effects of trees, shrubs, ground covers and open ground.

 

Communities that allow lot line to lot line paving do not recognize the fact that sites like this cause problems with drainage and flooding and water table recharge. Off site drainage transports sediments, pollutants and trash. It becomes other peoples problems.

 

It is usually the tax payer that picks up the tab for this “externality”of business and landscape codes can prevent this type of insensitive development.

 

 

It is interesting to note that this was the last project permitted and built prior to the adoption of the Baton Rouge, Louisiana Landscape Code on January 19th 1994. It was extreme action such as this of removing all aspects of nature from this development site and paving from lot line to lot line that encouraged community citizens to say enough is enough. They called upon the East Baton Rouge Parish Planning Commission to form a special committee to study the issue of a landscape code. Eighteen months later the first landscape code was enacted.  The code has been revised twice since then, each time upgrading the standards in response to citizen action.  It is clear from this one instance that most communities start the process of adopting a landscape code when citizens rise and indicate that nature in the city is to be protected, preserved and rebuilt following construction.

 

In this photo, the facility seen to the extreme right was built under the new landscape code standards.

 

 

 

 

 

 

19. (Parking Lot Design)

 

A recent urban forestry study in Sacramento, California by researchers at U.C. Davis provides us with new information about the importance of parking lots as an element of urban design.

 

Researchers studied fifteen parking lots to evaluate parking lot capacity and compliance with parking lot tree planting requirements of the local landscape code. (McPherson 2001) Researchers found that parking lots in this community accounted for thirteen (13%) of urban impervious surface and occupy five and six tenth (5.6%) percent of the cities total land area.  They found that the total number of parking stalls exceeded the zoning standards by six (6%) percent. When surveyed at peak occupancy times, they found that thirty-six (36%) of the spaces were empty indicating that parking was overbuilt for normal demand. The investigators suggest that a conservative twenty-five (25%) of the empty spaces, which occupy more than ten (10%) percent of the land covered by the parking lots be converted to non-pervious surfaces. (Wolfe 2003) This area of the site could be planted and paved for occasional use with grass, grass-crete, porous paving, unit masonry on a sand base, stabilized sand or gravel. All of these solutions would allow opportunity to park while increasing the amount of green on every development site.

 

 

The largest problem with community design is often how to effectively design parking lots. The second most common reason communities  draft a  landscape codes is to set standards for good design,  comfortable planting and safe pedestrian traffic within vehicular use areas (VUA). Good community design means good parking lot design. A well designed community will have parking lots that consider safe pedestrian traffic and safe automobile travel.  Pedestrian and auto conflict may be eliminated by good design practices. Parking lot design standards found in most landscape codes provide design guidelines for a variety of considerations. The following parking area design notes will help the reader understand the relationship of landscape codes to the design of vehicular use areas.

 

 

 

Parking areas should be designed for several purposes. The storage and movement of automobiles is just one of the functions the designer must consider. However there are others, such as traffic arrival and departure, service entry and drop off, ease of public security, ADA access, pedestrian safety and ease of maintenance. One of the most important jobs of a parking lot, a job often overlooked, is the to parking lots ability to 'do environmental work' to help cleanse the environment.

 

 

Known as vehicular use areas in the book Abbey. D.G., U.S. Landscape Ordinances, John Wiley, NYNY 1998 and in many landscape codes across the country, landscape codes generally set standards for the design of vehicular use areas.  Common vehicular use area standards found in many community landscape codes include standards that;

a.Size of parking lots which must comply with the landscape code.

 

b.Plantings per parking space or plantings based upon percent of parking area.

 

c.Minimum percentage of vehicular use area devoted to interior plantings.

 

d.Canopy coverage requirements and shading performance.

 

e.Relationship of trees to parking spaces include maximum distances.

 

f.Screening of parking areas from public streets and residential districts.

 

g.Protection of vegetation from vehicular encroachment and design of curbs.

 

h.Quantity of vegetation in vehicular use areas.

 

i.Specifications for plant materials used in parking environments.

 

j.Geometry of parking areas including the sizing for parking stalls, parking bays, interior islands, bay peninsulas divider medians, travel lanes and turning radiuses.

 

k.Reduction of impervious surfaces introduction of porous pavements.

 

 

 

Parking area design requires that the designer understand the principle parts of a parking lot and how they are designed.   The several parts consist of;

 

 

1.  access point or access way...these are the entry and exit points into a vehicular use area (VUA) which we commonly call a 'parking lot.'

 

 

2.  sight triangle...a small triangular area near the entry and exit point of parking lot or roadway which must be free of visual obstruction.

 

 

3.  travel lane....the center roadway or aisle in a parking lot. The travel lane can be one (15'wide) or two way (22' wide. Two way travel lanes generally have 90d angle parking.  One way travel lanes can have 60d or 45d angled parking.

 

 

4.  divider median....a continuous curbed planting area whose purpose is to separate roadways or parking bays. Width of divider median should match size of trees to be planted. Class A 20'minimum, Class B 15' minimum, Class C 8' minimum.

 

5.  parking space or stall....the space for the parking of one automobile, full size car 19' x 9,' compact car 17' x 9,'sub-compact (electric) 15' x 8,' and suv 22' x 10.' The size of a Hummer, a light truck or SUV, is 15.75' x 10.00' x 6.40' tall.

 

6.  tire stop...pinned concrete wheel barrier which is placed 24" or 36" from edge of parking area. The purpose of a tire stop to to keep autos out of planting areas.

 

 

7.  curb and or curb and gutter...the purpose of a curb is two fold, to constrain auto traffic and to direct rainwater to a catch basin. Common curbs are 6" to 8" tall and 6" wide at the top.  Gutters are generally 12" wide so a poured in place curb and gutters 18" wide.

 

 

8.  parking screen...a planted area which can be a thin as two feet or as wide as 6' which is used to plant shrubs and small trees whose purpose is to screen views of parked cars or to cast shade into the parking area. Shrubs are generally kept 36" tall.

 

 

9.  parking bay....a series of connected and continuous parking stalls. Most landscape codes require bays to be no longer than 8, 12, or 16 spaces without an internal planted island.

 

 

10. parking median or tree strip......a continuous curbed planting area whose purpose is to separate parking bays. The parking median, sometimes called a tree strip often will contain plantings, walkways and parking lot lights. Width of parking median should match size of trees to be planted. Class A 20'minimum, Class B 15' minimum, Class C 8' minimum. Some times as narrow as 6'. With no plantings this strip can be the width of a walkway 4' or 6' wide.  Most community landscape codes require that plantings of trees and other plants be used in parking lots so the unplanted parking median is becoming a thing of the past.

 

 

11. parking island.....a plant-able area separating one parking bay from another.  The width of island is usually 9' wide (but can be made wider) with a 6' radius on the corners of the end facing the travel lane. The total length of the parking island is normally the length of the parking stall.

 

 

12. parking peninsula......a plant-able area at the end of each parking bay. The width of this area is usually 9' wide (but can be made wider) with a 6' radius on the corners of the end facing the travel lane. The total length of the parking peninsula is normally the length of two parking bays plus the parking median.Generally 9' + 6' + 9.'

 

 

13. single parking lot.....is one travel lane and one parking bay. The maximum width with a one way travel lane would be 15'(travel lane) + 19'(90d parking stall) + 6' (vehicular use area screen).

 

 

14. double bay parking lot.....is one travel lane and two parking bay. The minimum width with a two way travel lane would be 6'(parking median) + 19' (90d parking stall) + 22' (travel lane) + 19' (parking stall + 6' (vehicular use area screen.  Curb to curb parking lot dimension is 60.'

 

 

15. parking angle......usually 90 degrees but can be 45 degrees or 60 degrees.

 

 

16. articulated cross walks.......walkways which cross travel lanes that are articulated with eight paint, various surface material or wheel bumps.