ppp ch.2 notes

8/3/2019 PPP Ch.2 Notes

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Chapter 2: Environmental Analysis & Project Planning

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N O M E N C L A T U R Ed = Vertical distance between contours (ft. /m)G = Slope of land (%)L = Horizontal distance between points of a slope (ft. /m)

I N F L U E N C E S O N U R B A N D E V E L O P M E N T Environment first affects how a site is developed & how building is designed, and then bldg affects community in

which it was built

H ist o r i ca l I n f l uences First Settlements Living quarters surrounded the granary, the temple & the palace

o For security villages were walled or situated for protection Greek Cities similar to first settlements but were more highly developed

o The Agora (marketplace) became a location for trading goods, meeting people, exchanging news & conductingother business

o Walled Greek cities also had special facilities (theaters, stadiums, etc.) Medieval Cities Irregular layout

o Started at crossroads of 2 main streets & were centered around the church &market

o Structures were near center of the city & surrounding was informal ring ofstreet loosely connected with intersecting streets running from the church to

the gates of the city wall Star-Shaped City Invention of gun powder led to a need for more security

o Base stations at points around the wall so the entire enclosure & all approachescould be protected

o Streets radiated out from the center so defense could be controlled from onepoint & it was easy to move troops and materials

Renaissance City Planning took on greater importanceo City Plans combined symmetrical order with radial layout of streets focused on points of interesto Christopher Wrens plan for rebuilding London after the great fire of 1666 & Haussmanns plan for Paris

Reflect this

Haussmann advocated straight boulevards connecting historic buildings, monuments & open squares Purpose of plan was to minimize riots, facilitate defense and clear out slums. It also improved transportation & beautified the city

o Camillo Sitte proposed cities be laid out on principals of medieval towns with irregular streets He felt views would be more interesting He proposed using T intersections to reduce the number intersection traffic conflicts He also created the Turbine Square: civic centers around a pinwheel arrangement of streets

Industrial Revolution (England 18th & 19th Centuries) Creation of the factory forced people to be close to thefactory, source of power & transportationo As factories grew, cities became overcrowded, dirty & lacked open space

Garden City Concept by Ebenezer Howard ~ one of the best reform movementso A 6000 ac tract of land be privately owned by the residentso At the center there would be civic buildings in a parko Surrounding the core would be housing & shops with industrial facilities in theoutermost ringo The Urban part would support 30,000 people on 1,000 ac; the remaining 5,000 ac

would be reserved for a green belt & house 2,000 people Cite Industrielle Planned city concept to be built in France by Tony Garnier in 1917

o Had separate zones for residential, public, industrial & agricultural use, linked by separated circular paths forvehicles and pedestrians

o Buildings would be placed on long narrow lots with ample space between themo W a s t h e f i r s t t o e m p h a s i z e z o n i n g


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Early U.S. Colonies were a reaction to Renaissance idealso Planned around a central commons center of communityo Houses were free-standing structures, set back from street with a back yardo H e l p e d s e t p r e c e d e n t f o r s i n g l e f a m i l y d e t a c h e d h o u s i n g

Gridiron Street Systemo Philadelphia (1682) based on a gridiron street systems with regularly planned public open spaces, uniform

spacing & setback of buildingso Savannah, GA (1733) Also a gridiron street systemo Encouraged by the Ordinance of 1785

Established the rectangular street system of the U.S. System divided the country into a grid of 24 mi squares, each divided into 16 townships, each 6 mi on a

side These were further divided into (36) 1 mi2

Washington D.C. designed by Pierre Charles LEnfant was one early city that broke the grid systemo Design was based on Renaissance and Baroque planning concepts of diagonal and radial streets superimposed

on the rectangle grid In landscape and park design Frederick Law Olmsted was one of the leaders

o With architect Calvert Vaux, designed NYCs Central Park in the 1850s Inspired similar designs for metropolitan parks across the country

One of the most profound changed in American urban design began with the Columbian Exposition in Chicago in1893o The exposition grouped classical buildings symmetrically around formal courts of honor, reflecting pools and

large promenadeso Started the City Beautiful Movement

A fairly recent notion of town planning is the New Town Concept Its an exception of the idea that entirely newcommunities can be built away from the crowding and ugliness of (E) citieso New Towns were supposed to be independent centers including housing, shopping, and business, surrounded by

a greenbelto Originally the population was to be limited to 30,000 people, but was later increased to 70,000 250,000

peopleo Columbia, Maryland & Reston, Virginia began as new towns but never became truly independent cities because

they lacked significant employment centers They depended on the jobs of nearby Washington D.C. and other areas

New Urbanism (1980s) a more recent planning philosophy that attempts to counter the many undesirableaspects of city development including suburban sprawl, reliance on the automobile, environmental deterioration,housing segregation, loss of farmland and single-use developmento Begun with construction of Seaside, Florida by Andres Duany & Elizabeth Plater-Zyberko Others who developed the principles of new urbanism were Peter Calthorpe and Peter Katzo Primary urban design features is the development if neighborhoods intended for mixed useo At the regional levels, new urbanism promotes the connection of neighborhoods and towns to regional

patterns of pedestrian, bicycle and public transit systems while reducing dependence on the automobileo At the street and building level, individual buildings integrated with their surroundings to support the street

as a place for pedestrian and to provide users with a clear sense of location and time

D e v e l o p m e n t P a t t e r n s Urban development can be viewed at two scales: the larger scale of the city and the smaller scale of the

community and neighborhoodo In the 20th century the pattern of development at the city scale has generally been determined by the

geographic features and the layout of transportation Cities begun near major geographic features tended to develop along the water and ultimately away from it. When begun in less confining circumstances, cities have grown equally in all directions, usually in uniform grid

patterns With the creation of the automobile, citied have expanded in an number of typical patterns

o These patterns affect the planning of the smaller scale communities and neighborhoods and ultimately canhave an effect on the design of the individual building projects


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Simplest pattern is the Expanded Grid city is formed at the junction of 2 roads,growth follows the grid pattern until some natural feature, limiting population oreconomics stops ito Usually a characteristic of smaller cities

Star Pattern revolves around the urban core and development along radiating spokesof main highways or mass transit route

o Higher density tends to form around the spokes with less density in between Field Pattern has no central focus or apparent overall organization scheme, developmenttakes place in an amorphous network of highways and natural featureso Example: L.A.

Satellite Pattern A central urban core with other major cores surrounding ito The central core is linked to the others with major highways and often the outer

cores are connected with a road system called a beltwayo The outer cores often begin as major shopping areas, peripheral business centers or

transportation centerso Example: Houstono Often a satellite pattern starts out as a star pattern.

Megalopolis two or more major urban centers near each other grow together as thespace between is developed

o Example: Many sections of the northeastern United States and Southern California One idea that is useful and linking the urban scale with the community scale is the conceptof imageability proposed by Kevin Lyncho Imageability the quality of a physical environment that gives it a high probability of

evoking a strong image in the mind of a observerso The hills of San Francisco a part of the image of that city in the minds of most people

who visit it or live there Lynch identified five basic elements of urban image created by buildings, natural features, roads and other

components of the cityo Site planning and building design should respond to the existing image elements and enhance them if possibleo Path a way of circulation along which people move

May be a street, pedestrian walkway, rail road, transit line or river Since circulation is an important part of any physical environment, paths are usually at the center of a

person's imageo Edges linear elements that form boundaries between two districts or that break continuity.

May be a shoreline, a line of buildings against a park, a wall, etc. Sometimes an element is a path if used for circulation and an edge if seen from afar (ex: highways). Edges may be either solid or penetrable.

o Districts are two-dimensional areas that people perceive as having some common, identifying character andthat they can enter Back Bay in Boston and Georgetown in Washington, D. C. are examples of districts

o Nodes the strategic centers of interest that people can enter May be the intersection of paths places where modes of transportation change, plazas, public squares

or centers of districts.o Landmarks similar to nodes in that they are point references, but people cannot enter, they are viewed

from the exterior

A tower, monument, building or natural feature can be a landmark. Street patterns also intimately relate to an individual siteo Initially community and neighborhood developments followed the layout of streets, usually a grido Blocks between the streets were subdivided into lots and each lot was developed as a separate entity

Although this development method exists today other approaches have emerged


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The Superblock is an outgrowth of the New town concept, the concept minimizesthe impact of the car on housing and allows the development of pedestriancirculation in park space within the blocko One of the first trials was in the new town of Radburn, New Jersey by Henry

Wright Here the attempt is made to plan a large piece of land that limited the

intrusion of cars A continuous street surrounded the superblock and vehicular access was provided with cul-de-sacs.

o The superblock this concept was used in the planning of that Chandigarh, India by Le Corbusier and of Brasiliaby a Lucio Costa and Oscar Niemeyer.

o The separation of the automobile on the side of the house that faces the street from the pedestrian andliving area on the other side seems to be an admirable goal. However, because much of contemporary life forballs around the automobile this separation can be counterproductive to neighborhood social interaction as aresult the driveways and parking spaces of superblocks are often used more than a quiet park spaces.

Planned Unit Development (PUD) each large parcel of land can have a mix of uses: residential, commercial,recreational, and open space designed with variable lot sizes and densitieso Industrial developments can also be planned as PUDso PUDs must conform to certain standards as propagated by the local planning agency and must be approved

by the planning agency

Within the restrictions the planner has wide latitude in determining how the site is developed. The standards include: uses permitted, total floor area ratio, amount of open space required, parking

spaces required, living space ratio, maximum heights, and setbacks at the perimeter.o They make more efficient use of land by grouping compatible uses without the requirements at setback

regulations in zoning ordinances. This allows the extra land to be given over to open space for common use areas. They also provide a variety of housing from single-family detached to row houses to high-rise

apartments and condominiums.o PUD's also provide some of the diversity and variety of urban living

T h e E f f e c t s o f D e v e l o p m e n t P a t t e r n s o n S o c i a l B e h a v i o r Density the number of people are unit of area (not to be confused with crowding)

o The perception of crowding also depends on cultural influences and circumstanceso Studies have shown that excessive density can cause physical and mental health problemso Taking cultural and social differences into account when designing housing and other facilities is critical to

successful project. People need and want social interaction with their family friends and neighbors and other groups.

o Sociopetal Spaces, buildings and grounds and even furniture that tend to bring people togethero Sociofugal conditions that tend to discouraged interaction or social contact

Concept of personal spaces that surround each individual proposed by Edward T. Hall states that there are fourbasic distances that can be used to study human behavior and serve as a guide for designing environments actualdimensions very with the circumstances and with cultural and social differences but they always exist.o The closest is intimate distance - ranges from physical contact to a distance of about 6 to 18

People only allow other people to come within this distance under special conditions. If forced this close together people have defense mechanisms, such as avoiding eye contact, to

minimize the effect of the physical contact.

o

Personal Distance, from about 1 ft to 2 ft If given the choice, people will maintain this distance between themselves and other people. Varies with culture

o Social distance ranges from about 4 ft to 12 ft. This is the distance at which most impersonal business, work, and other interaction takes place

between strangers or in more formal situations.o Public distance is the farthest, ranging from about 12 ft outward.

The greatest amount of formality can be achieved at this distance This distance allows people to escape if they sense physical danger from another person.


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Another principle concerning the effects of development patterns on social behavior is diversity.o Humans need a diverse and stimulating environment.o In a monotonous urban setting, community, or building, people tend to become depressed, become irritated, or

suffer some other type of negative influence Environment can also have an effect on criminal behavior.

o The concepts of defensible space have spawned the newer term "crime prevention through environmentaldesign" (CPTED).

o Newmans original concept of defensible space described a range of design elements that used the basicconcepts of surveillance, territoriality, and real and symbolic barriers to reduce crime.

o CPTED takes the idea further and includes additional methods to reduce crime, such as electronicsurveillance, alarms, and human resources.

C O M M U N I T Y I N F L U E N C E S O N D E S I G NC a t c h m e n t A r e a s All land development is dependent on/affected by population base in area. Catchment Areas - An area that affects a development site

o Example: A school district is catchment area for a school building Catchment areas can be defined by geographical features or arbitrary lines (political/school district) Catchment area size is dependent on several factors

o Residential Catchment area may increase with an increase in population Catchment boundaries are reliant on availability of transportation. In depth information about a Catchment area must be known in most cases

o Information usually obtained from census informationA c c e s s i b i l it y t o T r a n s p o r t a t io n The following should be considered when analyzing a site for development:

o Is there an adequate highway system to bring the catchment area population to the siteo Are there adequate traffic counts for businesses that depend on drive-by trade?o Would the development create additional traffic that would overload the (E) road system and require (N)

roads to be built or expanded?o Is there adequate truck access for servicing the site?o Does the surrounding transportation network create an undesirable environment for the development (too

noisy, etc.)?o Is there safe and convenient pedestrian access to the site if require?o Are there public transportation lines nearby? How can people get from the mass transit stops to the site?o Are rail lines available for industrial projects?

N e i g h b o r h o o d s Neighborhood A relatively small area in which a number of people live who share similar needs and desires in

housing, social activities and other day to day living aspects Original concept of the neighborhood as part of city planning was developed by Clarence Perry (1929)

o His ideas were primarily proposed as a way of bringing people together.o He felt neighborhoods should be centered around an elementary school, which serves a center of community

and be surrounded by major streets not intersected by them. The neighborhood has become the basic planning unit for contemporary American urban design Neighborhood is the scale people identify with most.

o Part of city that affects their lives mostPub l i c Fac i l i t i es Availability, location and relative importance of public facilities (schools, shops, churches, etc.) can affect how a

site is developed


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L A N D A N A L Y S I ST o p o g r a p h y A sites (E) topography affects:

o How the development can take placeo What modification need to be madeo What costs might be involved

Contour Lines are a graphic way to show elevations of land in plan view and are used to make slope analysis Contour Interval is the vertical distance between adjacent contour lines Slope is calculated using the formula G = ( d / L ) x 1 0 0 % Slope Analysis the (E) contours can be divided into general categories

o 0%-4% are usable for all types of intense activity and are easy to build ono 4%-10% are suitable for informal movement and outdoor activity & can also be built on without much

difficultyo 10% + are difficult to climb or use for outdoor activity and more difficult & expensive to build on o Depending on soil conditions, slopes over 25% are subject to erosion and even more difficult & expensive to

build on Recommended Grade Slopes for Various Uses:

Slopes (%)Min. Preferred Max.

Ground Areas for Drainage 2.0% 4.0%Grass Areas for Recreation 2.0% 3.0%Paved Parking Areas 1.5% 2.5% 5.0%Roads 0.5% 10.0%Sanitary Sewers (depends on size) 0.5-1.5%Approach Walks to Buildings 1.0% 5.0%Landscaped Slopes 2.0% 50.0%Ramps 5.0% 8.33%

Transporting soil to or from a site is expensive and not desirable; ideally the amount of soil removed from thesite for grading would be redistributed to fill in other areas of the site.

N a t u r a l F e a t u r e s A complete site analysis will include a study of desirable and undesirable natural features A view analysis may be required to determine the most desirable ways to orient buildings, outdoor areas, and

approaches to the buildings Significant natural features should be identified to determine whether they must be avoided or can be used as

positive design elements Subsurface conditions of groundwater and rock must also be known. Sites with high water tables (6ft 8ft below grade) can cause problems with excavations, foundations, utility

placement and landscapingo Generally the water follows the slope of the grade above, but it may varyo Boring logs will reveal whether groundwater is present and how deep it is

Sites with a lot of rocks near the surface can be expensive (or impossible) to developo Blasting is usually required and sometimes not allowed due to code issues

D r a i n a g e Every site has a natural drainage pattern that must be taken into account during design.

o Some drainage may be minor, consisting only of run-off from the site itself and a small amount from theadjacent sites. This type of drainage can be easily diverted around roads, parking lots, etc. and minor changes to the

contours of the lando Some have major drainage paths such as gullies, dry gulches or rivers may traverse the site

These have a significant influence on the site because in most cases they must be maintained Buildings must be built away from these or bridge them so that water is not restricted If contours need to be modified, it must be done so as not to disturb the adjacent properties


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o Site development may be so extensive that excessive runoff is created due to roof areas, roads andparking lots

o All these increase the runoff coefficient the fraction of total precipitation that is not absorbed into theground If the runoff is greater than the capacity of the drainage from the site holding ponds must be

constructed to temporarily collect site runoff and release it at a controlled rate

S o i l Soil pulverized upper layer of the earth formed by the erosion of rocks and plant remains

o Visible layer is topsoil mixture of mineral and organic material; may range from a few inches to a foot ormore

o Below topsoil is mostly mineral materialo Below this is a layer of fractured and weathered parent material of the soil aboveo Below this is solid bedrock

Soil is classified according to grain size and as organic/inorganic.o Grain size classification:

Gravel Particles over 2mm in diameter Sands Particles from 0.05mm to 2mm (finest visible grains) Silt - Particles from .002mm to .05mm (invisible, but can be felt as smooth) Clay Particles under .002mm (smooth & floury when dry, plastic and sticky when wet

All soils are a combination of the above Soil investigation will tell if soil type will create slippage or slides = useless for development Gravel and sands good for construction loads, drainage and sewage, but unsuitable for landscaping Silt stable when dry, unstable when wet. Swells and heaves when frozen and compresses under loads. Can

sustain lighter loads.o Building foundation or road base must extend below silt or be flexible enough to avoid damage.

Clay expands when wet and subject to slippage. Poor for foundation, landscaping, drainage & sewage Peat & organic materials are good for landscaping, but bad for foundations; usually have to be removed from site

& replaced with sands and gravel

T R A N S P O R T A T I O N A N D U T I L IT Y I N F L U E N C E SR o a d s Road availability and capacity can be primary determinant for how a site can be developed Four basic categories of roads

o Local Streets lowest capacity, provide direct access to building sites. Maybe be in form of continuous grid, curvilinear systems, cul-de-sacs or loops

o Collector Streets connect Local Street with arterial streets. Have higher capacity than local street, but not for through traffic Intersections at collector & local roads will have stop signs. Intersection with arterial roads will have traffic lights

o Arterial Streets major continuous circulation routes, carry large amount of traffic on 2-3 lanes Usually connect expressways Typically have no street parking Should not have direct access to building sites

o Expressways limited access roads designed to move large volumes of traffic between, through and aroundpopulation centers Intersections are made by a system of ramps No pedestrian access Have a major influence on land because they require a lot of space, have a visual impact and create

noise Site analysis should take into consideration the (E) road configuration; planning should try to minimize congestion

and dangerous intersections


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Guidelines for Road Layout

Roads should be laid out in both horizontal and vertical directions, called Horizontal Alignment and VerticalAlignment

Straight sections of road are called Tangents Should generally be a minimum of 100ft between curves in opposite directions and 200ft between curves in same

directiono Multiple radius curves should be avoided

Vertical alignment must be designed to provide a smooth transition between grade changes & avoid steep gradeso Depending on weather conditions, streets should not have more than 10% grade

P u b l i c T r a n s i t A site analysis should include a determination of the types of public transit available & the location relative to

the siteo Building entrances & site feature should be easily accessed by public transito In large cities, site development may have to include provisions for public access to subway and rail lines

S e r v i c e A c c e s s Service access to a site includes provisions for truck loading, moving vans an daily delivery services Ideally service access is separate from vehicle and pedestrian access Spacing for truck turn-arounds and loading dock berths need to be provided

o Local zoning usually specified the number and size of loading berths Generally should be 10 - 12 wide at least 40 long and have 14 vertical clearance and must have a

minimum 60 turning radius (if turnaround is needed)Ut i l i t y Ava i l a b i l i t y Site analysis must determine the availability, location and capacity of existing utilities The potential development of a site is dependent on the availability of necessary utilities (water, sanitary

sewers, storm sewers, telephone service, gas service & other public utilitieso If utilities have to be brought from a long distance it can be very expensive

Generally utility lines follow the street layout and right-of-way o Sanitary sewers, storm sewers & water mains are located under roadso Electrical and communication lines are adjacent to the roadso Gas lines can be either underground or above groundo Utilities may also be located on easements (portions of privately owned land that public utility companies

can access for installation and maintenance) When new services have to be installed sanitary and storm sewer locations take precedent because sewers must

use the flow of gravityo Collection systems drain to city disposal systems or to private on-site treatment facilities


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C L I M A T E I N F L U E N C E S There are two aspects of climate analysis:

o Macroclimate overall climate of the region and is reflected in the weather data available from the nationalweather service From this information a region is classified as cool, temperate, hot-arid, or hot-humid

o Microclimate the site-specific modification of the macroclimate by such features as land slope,trees/vegetation, bodies of water, and buildings

Undesirable climatic effects can be minimalized and desirable effects can be maximized by careful planningW i n d P a t t e r n s Prevailing wind patterns and microclimate wind effects must be studied during site analysis

o Buildings can be located to take advantage of breezes or avoid cold winds Wind on top of a hill can be 20% higher than wind on flat ground

o Leeward side of a hill away from the wind direction o Windward side of a hill near the wind direction

Near large bodies of water, warm air rises over warm land during the day and causes a breeze from the water, atnight cold air flows down hill and settles in low-lying regions

Wind patterns can be modified by buildings and trees o For a line of trees 50ft -150ft deep, wind velocity can be reduced 30%-60% to a distance 10 times the

height of the tree line and about half that up to 20 times the height of the tree line In temperate climates the best microclimates for wind are on the south or southeast facing slopes, in the middle

of the slopes or towards the topSo l a r Or i e nt at i o n The amount of solar radiation depends on the angle of the suns rays to the surface

o In the northern hemisphere south facing slopes tend to be warmer than other slopes and flat surfaces,especially in the winter

Albedo the amount of radiation that is reflected off a surface, expressed as a number from 0-1o High albedos = reflect a lot of radiationo Low albedos = absorbs a lot of radiation

Natural materials (grass and plants) have low albedos, pavement and snow have high albedos Conductivity the time rate of flow of heat through a material

o High conductivity = heat passes through quicklyo Low conductivity = retards the passage of heat Natural materials have low conductivity Metals, concrete & masonry have high conductivity

Albedo and conductivity combined affect the microclimateo Low albedo and high conductivity = moderate and stabilize microclimate

Heat is absorbed quickly, stored and released when the temp. drops Surfaces with grass and plants are cooler in hot weather for this reason

o High albedo, low conductivity = are much hotter than macroclimate would beS U S T A I N A B L E D E S I G NGenera l Eco l o g i ca l Co ns id erat i o ns Ecology Study of organisms in relation to their environment Applied to site development = the need to understand the impact of construction on the surrounding natural

environmento Result = Federal agencies file environmental impact statements (EISs)

Req. started as part of the National Environmental Policy Act of 1969 and is enforced by the EPA Requires a formal process to predict how a development will affect environment (air, land, water &

wildlife) Another factor of site development ecology is the impact on smaller-scale buildings


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Site analysis for semi-rural or rural development should assess the impact on natural landforms, water runoff,wildlife and (E) vegetationo Development should disturb natural contours as little as possibleo (E) drainage must be left intact & additional drainage should not exceed capacity of (E) drainageo Should also avoid significant disturbance of wildlife and plants

Site analysis for urban sites should focus on relationships of artificial systems more that natural ecosystemso

Development should minimize production of noise and pollutiono Bldg. Placement should avoid undesirable wind conditions on itself and neighboring buildingso Should minimize blocking sunlight from adjacent buildings and outdoor spaceso Should avoid annoying reflection/glare on neighboring buildings.o Must thoroughly understand the impact of development on utilities and transportation systems.

S i t e A n a l y s i s Sustainability issues should be considered when analyzing the site: Determine which sites or portion of sites should not be built on, this includes:

o Wetlands or sites within 100ft. of wetlandso Elevations lower than 5ft. above the 100-year floodplaino Habitats for endangered specieso Potential historic siteso Prime farmland

Determine historical and cultural qualities of the surrounding areao Building may want to reflect significant historical or cultural influences

Analyze types of developments might surround site in futureo Could affect location of building on site, connection with transportation, view corridors, etc.

Analyze (E) air quality as well as estimated effects of proposed developmento Should be done by a professional laboratory

Test soil and groundwater for contaminateso Could affect building location and mitigation methods

Determine presence of endangered species (Plants, insects and animals)Sit e a nd Bu i l d i n g Co ncep t s Us i n g Sust a i n ab i l i t y Building Location

o Try to build on urban sites or sites with (E) infrastructure Minimizes disruption of undeveloped land Maximizes efficient use of transportation and utility services

o Encourage mixed use developmento Locate buildings near public transportationo Locate buildings in a way to minimize tree and vegetation clearing, take advantage of solar access and

minimize detrimental effects of windo Minimize solar shadows on adjacent properties

Use setbacks or low building heightso Locate buildings in a way that maximizes desirable airflow patterns o Locate buildings in a way as to use gravity sewer systems

Building Size, Shape, and Designo Minimize bldg. footprint by using multiple floors whenever possibleo Design building dimensions to optimize material use and reduce waste o Use garden roofs or highly reflective coverings to minimize heat island effecto Plan buildings to include bike storage and shower/changing facilities

Site Disturbanceo Plan buildings and parking on previously disturbed land o Position buildings along landscape contours and shallow slopes to minimize earth work and site clearing o Plan utility corridors along new road or walkways or previously disturbed areas on site o Limit site disturbance to 40ft. beyond the perimeter, 5ft. beyond roadway curbs and walks and 25ft.

beyond constructed areas with permeable surfaces Site Development


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o Minimize site development by providing some or all parking under the building o Develop a site plan to minimize road length, parking and service areas.

Consolidate pedestrian, auto and service paths Double load parking lots to share access lanes and minimize paving

o Do not develop more than the minimum required parkingo Reduce heat islands by providing shade or using high albedo materialso

Use open grid paving or other pervious materials to reduce storm water runoff o Plan pedestrian surfaces using permeable materialso Use mechanical or natural treatment systems for storm water such as:

Constructed wetlands Filter strips Infiltration Basins a closed depression in the earth from which water can escape only into the soil Bioswale - a shallow lined ditch or channel designed to detain storm runoff and remove sediments and

other contaminates while allowing water to seep into the ground. o Design vegetative buffer areas around d parking lots to mitigate runoff of water containing pollutants o Minimize site lighting and prevent light from spilling onto adjacent properties or into the sky o Consider using collected rainwater for supplemental irrigation (if allowed by state and local regulations)

Annual rainfall must be enough to make this feasible Areas with poor air quality may yield water that is not suitable for this Roofing materials must be carefully selected Cost of collection, storage and filtrations must be carefully evaluated If rainwater cannot be collected use and infiltration basin

o Use native plant materials to minimize use of high maintenance lawnsL E G A L A N D E C O N O M I C I N F L U E N C E SZo n i n g Most common form of legal constraint on land development s is zoning Zoning took on a legal status in the first part of the 20th century

o It was originally an attempt to improve problems of expanding cities Crowding, factories being built too close to housing, tall buildings blocking light and air

First zoning ordinance was passed in 1916 in NYCo Was the first attempt by a municipal government to control the use of land and location of buildings Zoning the division of a city or other governmental unit into districts and the regulation of the use of land and

the location and bulk of buildings on a property within those districts Zoning primarily regulates:

o The uses allowed on a parcel of land depending on the zoning districto The area of the land that may be covered with buildingso The bulk of structureso The distance the buildings must be set back from the property lineso Parking and loading space requirements

Other requirements, such as regulations of signs and bonuses for providing plazas and open space may also beincluded

Special types of zoning may include:o

Rural zoning: separates agricultural uses from forestry or recreational useo Floodplain zoningo Airport zoningo Historic area zoning

Uses are established for the zoning districts based on residential, commercial and industrial occupancies, withsubdivisions of each of theseo Residential zones may include:

Single-family Low-density multifamily High-density multifamily


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o For each district a list of permissible uses is specified Single-family is the most restrictive

o Each zone can be used for the purposes listed for that zone and for any use listed in a more restrictivezone

The amount of land that can be covered is determined by the interrelationship of 2 zoning restrictions: setbacksand floor area ratioso

Floor Area Ratio (FAR) ratio of the gross floor areas within a structure to the area of the lot FAR = 1.0: 50% site coverage, 2 stories FAR = 3.0: 25% site coverage, 12 stories or 50% site coverage, 6 stories

Another common zoning tool is the bulk plane restrictiono Sets up an imaginary inclined plane beginning at the lot line or the center of the street and sloping at a

prescribed angle toward and over the lot The building cannot extend into this plane Purpose is to ensure adequate light and air to neighboring properties and to open space and street

around the land Sometimes zoning ordinances also have a maximum number of stories or height a building can be Sometimes zoning restrictions can cause a hardship or dont cover a unique situation and owner can apply for a

varianceo A public hearing is a part of the variance process to allow neighbors and anyone interested to object to the

application if they wish New zoning ordinances do not apply to (E) non-conforming uses unless the property changes its use, it demolished

or destroyed in a fire A zoning board (planning commission) can grant a conditional use permit

o Allows a non-conforming use or other use in the zoning ordinance if the property owner meets certainrestrictions

E a s e m e n t s a n d R i g h t s - o f -W a y Easement The right of one party to use a portion of the land of another party in a particular way

o Is a legal instrument and is usually recordedo Most common is a Utility Easement allows utility companies to maintain and install lines above or below

ground within the easemento No permanent structure are allowed to be built within the easement without permission from the party

holding the easement

o Another type is an Access Easement If one parcel is not served by a public road and another parcelseparates it from the road, an access easement may be granted, which allows the public and the owner ifparcel #2 the right to cross

o Support Easement for the construction of common party walls between propertieso Joint Use Easement allows 2 or more property owners to share a common feature such as a drivewayo Scenic Easement protects view and development in scenic areaso Conservation Easement limit land use in large areas

Right-of-Way legal right of one party or the public to traverse land belonging to anothero Most common form: a right-of-way refers to the public land used for street and sidewalkso Boundary of a right of way usually corresponds to the property line of adjacent property

In most cases the street occupies on a portion of the right-of-way, the remainder is used forsidewalks, landscaping and utilities

An access easement creates a private or public right of wayD e e d R e s t r i c t i on s Restrictive Covenants - Provisions in the deed that restrict the use of the property by the buyer

o Common for the developer of a large tract of land being subdivided to include o Often include limitation like setbacks, minimum sq. ft. of houses, types of materials that can and cannot be

used on the exterior and similar provisions o Because the covenants are in the deed the buyer can decide not to buy the property if the covenant are not

acceptableo Most deed restrictions are generally established for a certain period of years.


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L a n d V a l u e s As part of the overall economic analysis for potential development or reuse of an existing building, and the cost

of the property is vital in making a decision concerning site selection In addition to the land acquisition costs, there are costs of site improvement, building construction, appraisal,

financing, professional fees, permits, and maintenance of the complete structure.o If all of these cannot be paid off in a reasonable amount of time and yield a profit, the site is probably a poor

economic decision Land values are generally based on location, potential profit making use and local market conditions, which includes

demand for lando Location includes: potential surrounding market, population density, special features of the site and proximity

to transportation and utilities Land values are based on highest & best use There are three basic ways land is valued

o Market Approach - The surrounding neighborhood or region is investigated to find properties that haverecently sold or are on the market that are similar to the property being value except for adjustments toreflect the unique nature of the property. The property is assumed have the same value as that of thesimilar property. Land is commonly assigned to value per square foot or per acre and buildings are often valued at a cost

per square foot The assumed value of another property can be determined simply by multiplying the current market

value per square foot times the area of the property being evaluated.o Income Approach The basis is the potential the property has to yield a profit.

The potential income is estimated allowing for vacancies and credit losses and then various expensessuch as taxes, insurance and maintenance are deducted.

Because potential income is usually figured on a yearly basis, this amount must be capitalized toestimate the current total value of the property.

o Cost Approach The land is estimated at its highest and best use, and then the cost to replace the buildingor add improvements is calculated. The estimated accrued depreciation is figured and subtracted from the replacement cost a cost of

improvements. This adjusted amount has been added to the land value to give the total value of the property.

T a x s t r u c t u r e The taxes to which the developer is subject can influence whether a project is undertaken and how the sitedeveloped. Many tax rates are based on a mill levy on the assessed valuation of the piece of property

o A Mill is 1/1000th of a dollar or 1/10th of a sentence.o The assessed valuation is a percentage of the actual value of the property and the taxing authorities set

the percentage.o Taxing authorities may offer various types of tax incentives to developers as a way of implementing public

policy.o Tax incentives may turn an otherwise uneconomical project into a viable one.

L i f e - C y c le C o s t A n a l y s i s Life-Cycle Cost Analysis (LCC) is used to evaluate the economic performance of the material or building

system over the service life of the material a system.o The LCC includes all costs associated with purchasing, installing, maintaining and disposing of an item for the

time the item is installed in the building through the duration of the LCC study period. Life-Cycle Assessment Analysis (LCA) - Evaluates the environmental impacts from initial raw material

extraction to final recycling reuse for disposalo It includes raw material extraction, material processing, the manufacturer of intermediate materials,

fabrication, installation in the building, operation, maintenance, and the final disposal or reuse.

P u b l i c W o r k s F i n a n c i n g There are several ways Government agencies can finance public works projects. These include:

o General Taxes any tax imposed for general governmental purposes.


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o Property Taxes are an ad valorem tax, a tax based on the value of property being taxed Money collected by a municipality is placed in a general fund and used as required by that jurisdiction. Although general taxes may be used to fund public works, they typically used to provide ongoing

operation and maintenance of existing facilities and normal capital improvements. General taxes or increases to general taxes may be limited or may require a boat of the general

population. An increase in property taxes usually occurs when the local jurisdictions tax assessment officeincreases the value of the property even if the rate of taxation is unchanged.

o Special Tax - Any tax imposed for a specific purpose or by a single-purpose authority. Special sales taxes require a majority vote of the people in the district. An example of this type of tax is one to find a major transportation projects.

o General Obligation Bonds - are issued by a city or state and backed by general tax revenue and issuerscredit. Theyre used to finance the acquisition or construction of specific public capital facilities and to

purchase real property The jurisdiction issuing the bond is authorized to levy a property tax at the rate necessary to repay

the principal and interest of the bonds, usually over a period of 10 to 30 years. Each GO bond measure requires approval of the voters. Examples of projects funded with GO bonds include schools, museums, and libraries.

Because all taxpayers in the jurisdiction issuing the bonds must contribute a property tax to payoff the bonds of butter majority is required.o Revenue Bonds - often called rate-supported bonds are similar to general obligation bonds in that the local

government issues them to pay for facility or improvement. These bonds are backed by the revenue are a rates from customers using the services that the bond

funding paid for. In most cases rates increase to pay for retirement of the bonds. City water and sewer facilities often use this method of financing.

o Public Enterprise Revenue Bonds - issued by cities or countries to finance facilities for revenue producingpublic enterprises. The bonds are paid off from revenues generated by the facility through the chick chargesvampires. Airports, parking garages, and hospitals are examples of facilities that may use this method offinancing.

o A city can use Tax Increment Financing to pay for improvements based on increased taxes due to theincreased value of the property. A city creates a special district and makes public improvements within that district that will generate

private development. The assessed value of the property within that district is determined, and taxes based on that value

are frozen for a defined period of time set forth in the development plan. Sponsor issued at the beginning of the redevelopment. Each texting jurisdiction continues to receive its

share of the taxes based on the original assessed valuation. At the end of the development period, if that's valuation increases due to the new development, and the

increased taxes the tax increment go into a special fund created to retire bonds issued kid originatethe development tax increment financing is used for purchasing land planning and public Worksimprovements to encourage private development. It does not require a vote by the people in thedistrict.

Development Impact Feeso Development Impact Fee - Cost charged to the developers for off-site infrastructure improvements made

necessary by new development. These fees are way to make developers rather than the existing residence responsible for the costs

necessitated by the development. Impact fees may be made in addition to other exactions, such as hookup fees for utility service, and can

be used for projects such as street improvements or construction of wastewater treatment plantsimpact fees can be controversial.

Subdivision Exactionso Subdivision Exactions Similar to development fees in that they put a burden on the developer, but is not

used to fund construction.


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There are requirements that developers either dedicate some land for public use or contribute cash forthe purchase of land and facilities made necessary by local governments.

Special District Assessmentso There are several variations of Special District Assessments often called business improvement districts

BIDs or benefit assessments. These fees are used to fund public space improvements (parks &streetscapes)

o A special district is established to include the properties that will benefit from the proposed improvements. If a majority of the property owners in the area agree to arrangement, then all owners within the

districts boundaries are required to contribute. Taxes are assessed on those property owners in the district who benefit from the improvements

o Used to improve or maintain (E) facilities, not intended to encourage private developmentE V A L U A T I N G E X I S T I N G S T R U C T U R E SSurvey i n g Ex i st i n g Bu i l d i n g An existing Building survey should include the following:

o Site Feature parking, service access, adjacent properties, water features, etc.o Size and configuration of the structure overall size and shape, height, location of columns & other major

structural components Also includes location of partitions, toilets, mechanical rooms, and other service areas

o Roof including type, condition (leaks, water damage, etc.), and expected remaining lifeo Exterior Envelope type and condition (including windows, insulation)o Mechanical System type of heating and cooling, capacity of central plant and the condition of the

distribution systemo Plumbing System capacity of service to the building, sewer capacity, condition of pipes and fixtures &

number of fixtureso Electrical capacity of service to building,condition of primary and secondary service, condition of wiring

devices and condition of lighting and other electrical components o Fire Protection condition of the sprinkler system, pipe sizing and spacing of heads o Major equipment (if applicable) items such as refrigeration equipment or laboratory equipment o Finishes the condition and expected life of major surface finishes o Condition of the structure for accessibility, egress, and fire-rated elements

D o c u m e n t i n g B u i l d i n g S u r v e y s The building survey is typically documented in several ways: manually drafted drawings, CAD drawings, notes,

formal reports, photographs and videoso Normally accuracy to within is sufficient

M e t h o d s o f F i e l d M e a s u r i n g Hand measuring useful & low-cost

o Best for buildings of moderate size and complexityo Can record small details that cannot be seen by instruments using other techniques

Low-cost line of site sonic devices can be used by one person and give accuracy for many uses o Range is limited and cannot differentiate between closely spaced elements

Electromagnetic Distance Measurement (EDM) uses laser-based instrument with an onboard computer tomeasure the distance, horizontal angle and vertical angle

o Has accuracy to +/- 1/16 in 1600ft.o Two people are required to operate equipment

Reflectorless Electromagnetic Distance Measurement (REDM) does not require the use of a prism reflector,but instead relies on the return signal bounced from the object being measuredo Has an accuracy of +/- 1/8 in 100ft.

Image-based techniqueso Rectified Photography Uses large format, film-based view cameras to photograph facades

The focal plane is set parallel to the faade and gives a flat image with no perspective distortion Dimensions can be scaled off the image


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To improve accuracy the building plane should be relatively flato Orthography relies on digital photography and correction of optical distortion through computer softwareo Photogammetry the surveying of objects or spaces through the use of photography and associated

software Stereophotogrammetry uses 2 overlapping photographs in a computer program to produce a digital

stereo image. The image can be used to create a 3D drawing. It requires special equipment, software

and trained technicians Convergent Photogammetry uses multiple oblique photographic images of an object taken at differentangles. Using software that traces multiple photos derives measurements & 3D models. Thistechnique requires that reference points be established by standard surveying techniques. Itsinexpensive, but slower than laser scanning. Its accurate to +/-0.05%.

Laser Scanning uses medium-range pulsing laser beams, which systematically sweep over an object orspace to obtain 3D coordinates of points on the surface. No surveyed reference points are needed.Has an accuracy from +/-0.05% - +/-0.01% or better

E v a l u a t i ng E x i s t i n g S t r u c t u r e s Evaluating existing structures involves answering the following basic question:

o Does the site work for the new use or can it be adapted for the new use within the constraints of timebudget?

o Is this size and configuration of the existing structure adaptable for the new use within the constraints oftime and budget?

o Is there appearance and character of the structure consistent with the clients design goals and desiredimage?

o How much work and cost are needed to repair, renovate or modify the structure for the new use? Willseismic renovation be required?

o How much work and cost are needed to repair, renovate or modify the structure? Is the cost of addingsprinklers justified based on code requirement trade-offs and possible lower insurance rates?

o Does the new occupancy work within the constraints of the existing buildings construction type and area?o What additional work is required to bring the structure in compliance with current applicable codes and

regulations?o How much of the existing structure must be modified to conform to code requirements? Can this be done

within the constraints of time and budget?o If budget is not already established, how much will the minimum required amount of renovation cost? How

much will the desired amount of work cost? How long might the project take to complete?

E V A L U A T I N G H I S T O R I C S T R U C T U R E SD e f i n i n g t h e S c o p e o f t h e P r o b l e m If the structure is a national historic landmark or has similar landmark status on the state or local level, specific

requirements will influence the kind of rehabilitation work allowed. If the owner wants to receive federal tax credits, the rehabilitation must qualify as a certified rehabilitation. In

this case, the secretary of the Interiors Standards for Rehabilitation must be met. If the property is designated as a state or local historic landmark, the state historic preservation officer should

be contacted. The four treatments, listed in hierarchical order from most historically accurate to least, are:

o Preservation attempts to retain all historic fabric through conservation, maintenance, and repair.o Rehabilitation emphasizes the retention and repair of historic materials, but gives more latitude toreplacement because it assumes the property is more deteriorated prior to work.

Both preservation and rehabilitation focus attention on the preservation of those materials, features,finishes, spaces, and spatial relationships that give a property its historic character.

o Restoration focuses on the retention of materials from the most significant time in a property's history,while permitting the removal of materials from other periods.

o Reconstruction is the least historically accurate and allows the opportunity to re-create a non-survivingsite, landscape, building, Structure, or object in new materials


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D e f i n i n g R e g u l a t o r y R e q u i r e m e n t s As codified in 36 CFR 67, the Historic Preservation Service of the National Park Service has established 10

general standards to guide historic preservation (often referred to as the Secretary of the InteriorsStandards for Rehabilitation. When federal investment tax credits are involved, these standards takeprecedence over local requirements.o A property shall be used for its historic purpose or be placed in a new use that requires minimal change to

the defining characteristics of the building and its site and environment. o The historic character of a property shall be retained and preserved. The removal of historic materials or

alteration of features and spaces that characterize a property shall be avoided.o Each property shall be recognized as a physical record of its time, place, and use. Changes that create a

false sense of historical development shall not be undertakeno Most properties change over time; those changes that have acquired historic significance in their own right

shall be retained and preserved.o Distinctive features, finishes, and construction techniques or examples of craftsmanship that characterize

a property shall be preserved.o Deteriorated historic features shall be repaired rather than replaced. Where the severity of deterioration

requires replacement of a distinctive feature, the new feature shall match the old in design, color, texture,and other visual qualities and, where possible, materials. Replacement of missing features shall besubstantiated by documental}', physical, or pictorial evidence.

o Chemical or physical treatments, such as sandblasting, that cause damage to historic materials shall not beused.

o Significant archeological resources affected by a project shall be protected and preservedo New additions, exterior alterations, or related new construction shall not destroy historic materials that

characterize the property. The new work shall be differentiated from the old and shall be compatible withthe massing, size, scale, and architectural features to

o New additions and adjacent or related new construction shall be undertaken in such a manner that ifremoved in the future, the essential form and integrity of the historic property and its environment wouldbe unimpaired.

S u r v e y i n g t h e H i s t o r i c S t r u c t u r e The structural survey must include an assessment of settlement, deflection of beams, and structural members

damaged in previous renovations or for mechanical and electrical services. The physical survey should determine if original or historic elements have been removed or altered, and if so,

what their original appearance was. The architect should identify the aspects of the building that define its historic character and set them in a list

of priorities.o These characteristics include the overall form of the building, its materials, spaces, and workmanship, and

other notable features that distinguish it from other buildings.

A R C H I T E C T U R A L P R A C T I C E A N D S E R V I C E S D U R I N G P R E - D E S I G N The factors that are involved in this decision include:

o The current workload of the architects officeo The match between the project and the types of work the architect's office is qualified to do or preferso The potential feasibility of the projecto The owner's budget both for the project and for feeso The reliability and reputation of the client The amount of work the client requests exceeds the budget for either construction or professional fees, orboth.o In this case, the architect must either decline to accept the job, accept a lower profit margin, or negotiate

with the owner to reduce the scope of the project or the scope of the architect's services. The architect should investigate the client, including the client's ability to fund the project, past experience with

building projects, and experience with working with design professionals. If the architect decides to accept the job, the architect must first negotiate an agreement with the owner that

determines the scope of the work, fees required, and other aspects of the contract


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o This agreement may also involve developing a preliminary design and construction schedule to help determinethe project's feasibility, as well as the anticipated fees required by the architect.

The architect cannot accept work from the owner unless other architects or design professionals has severedtheir relationship with the owner.

C o o r d i n a t io n w i t h R e g u l a t o r y A g e n c i e s The work involved for coordinating with code agencies may include developing preliminary site plans and land-use

proposals. Sketching preliminary building designs, and meeting with governmental agencies and neighborhoodgroups.o This work requires additional fees beyond the normal fee for building design, so the architect must estimate

the time and costs required for the work. If the building presents unusual design challenges and requires zoning variances or unusual building techniques or

materials, the architect will have to work with building officials or zoning regulators early in the pre-design phaseto obtain advice and approval of any deviation from zoning requirements, or to use alternate means and methodsof construction as allowed by building codes.

Co nsu l t a nt Co o rd i n at i o n The architect should involve the consultants in the project as early as possible One of the most important tasks for the architect during pre-design is the assembly and coordination of the

various consultants on the project. The expected services of each consultant must be determined with the advice of the consultant and theapproval of the client.

o The involvement of the client is mandatory if the owner contracts directly with the consultant for services. If the owner contracts directly with the consultant, the architect avoids any problems with contract

provisions and payment, but may lose some ability to direct the consultant.o If the architect writes an agreement directly with the consultant and is responsible for paying the

consultant, the architect has more control but may encounter problems with paying the consultant's fees ifthere isdelayed payment from the client.

Once the consultants are retained, the architect should inform the appropriate consultants about the applicablecode requirements.o The architect is also responsible for informing the consultants of any design decisions that may have code

implications.o AIA document C141, the Architect-Consultant Agreement, states that the consultant is responsible for

code compliance regarding their area of work in the same way the architect isresponsible to the owner

under the ALA B14l, Owner-Architect Agreement.o The AlA C14I document also states that each consultant is responsible for the accurate production of the

consultant's own drawings and specifications. The consultant is responsible for checking his or her own various documents for consistency.

o The architect is the prime consultant and is liable to the owner for the consultant's work.

ppp ch.2 notes

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