Environmental Conditions & Context Flashcards
Aboveground drainage systems
Pervious paving, sheet flow, gutters in roadways and parking areas, ground swales in landscaping, channels
Underground drainage systems
Perforated drains and enclosed storm sewers to carry runoff away from the site to a municipal storm sewer or natural outlet like a river
Minimum slope for very smooth surfaces
.5%
Minimum slope for most paved surfaces, accounting for roughness and variations
1.5%
Minimum slope for underground pipes
.3%
Drain inlet
An opening in the ground that allows stormwater to run directly into the storm sewer; the opening is covered with a metal grate for safety and to keep out debris
Catch basin
Underground reservoir with a built-in sump pump; debris settles into the sump instead of flowing down the sewer and potentially clogging the pipes; sump needs to be cleaned out on occasion
Where should storm sewer manholes be located?
Wherever the sewer changes direction or a maximum of 500’
Storm sewers are always kept separate from
Sanitary sewer system
Runoff coefficient
The fraction of water not absorbed
What is the capacity of a drainage system based off?
The size of the area to be drained, the runoff coefficient, and the amount of water to be drained during the most severe storm anticipated by the design (N-year, most often 25- or 10-year storms)
Which utilities usually take precedence when locating a building?
Sanitary sewers and storm sewers, because they depend on gravity
Size and sloe of sewer piping depends on:
Capacity needed to service the building
Where is the actual connection of the building sewer and the main line
At an elevation above the invert of the main line at any given point in order to not interfere with the free flow of the main line
Minimum slope for building sewer
.5% to 2% depending on the size of the pipe; greater slope for smaller pipes:
2.5” pipe at 1/4 in/ft
3-6” pipe at 1/8 in/ft
8” or more pipe at 1/16 in/ft
Maximum slope for a road
15% for short distances, but 10% or less is preferred
Before crossing a sidewalk, the road must do what?
Become level after a ramp
Crowns and gutters should be used for what?
To slope water; crowns are 1/4 in/ft minimum and gutters are 6” high
Collector walks
Should be located next to parking areas
Should be a min of 6’ wide, especially is car bumpers overhang it
Provide seating, lights, and trash collection
1/4 in/ft slope across the walk
Exterior ramp requirements
36” minimum width
1:12 max slope
5’ minimum length landing at top and bottom
30’ maximum run between landings
30” maximum rise between landings
34-38” height from surface of ramp to center of handrail
Handrail required on both sides is rise is greater than 6”
Extend handrail 12” beyond top and bottom of ramp
Curb cuts are 1:10 max slope at the edges
Exterior stair requirements
Rise 6” maximum, 4” minimum
Tread 14” for 6” in rise
Slope tread 1/4 in/ft from riser to nosing for drainage
Minimum 3 risers
Maximum 10 risers between landings
34-38” height from surface of ramp to center of handrail
Provide handrail over 4 risers or where icy conditions exist
Extend handrail 12” beyond top and bottom of stairs
Parking capacity is determined by
The requirements of the zoning ordinance or by the building program
Parking space standard size
9’W x 19’L
Parking space compact size
7’-6”W x 15’L; zoning ordinances may allow for a percentage of parking space to be compact
Most efficient parking in terms of land use
90 degree
Angled parking
Easier to use, uses 1 way circulation, requires less total width
Parking area used for prelim evaluation
400 SF per car; includes parking spaces, drives, and minimal landscaping
Parking lot drainage
1.5-5%; 2% can be used for convenience
Water to drain towards edges
Curbs must have curb cutouts or drains
Landscaped planting strips
7’W between paved areas and in parking lots; 4’W for grasses and ground covers
Contours of the land cannot be changed where?
Within the drip-line of a tree
Azimuth
Compass orientation of the sun, usually degrees east or west of south
Altitude
The height of the sun measured at an angle from the horizon; horizon is 0, directly overhead is 90
Rectilinear Projections
A type of chart where the solar azimuth is plotted along the horizontal axis, and the solar altitude is found along the vertical axis
Equidistant Horizontal Projections
Plots the path of the sun at various times of the year on a circular chart; the spokes represent the solar azimuth; the curved lines overlaid are the path of the sun on different dates based on the latitude; intersecting lines are the time of day
Gnomonic Projection or Sunpeg Chart
Derived from the sundial projection, useful for shadow studies
Passive Solar Design
Direct gain systems
Indirect gain systems
Thermal storage wall
Phase change materials
Greenhouse design
Roof pond
Convective loop systems
Active solar design requires 3 components
A collector (flat plate or a focusing collector), storage device, and distribution system
Flat plate collector
A network of pipes located on an absorptive black surface with low emissivity, placed below a covering of glass or plastic; the pipe carries the heat transfer medium, usually water with antifreeze
Focusing collector
Parabolic reflectors that focus the incoming radiation to a single pipe that carried the heat-transfer medium; operates at a much higher temp than flat-plate collectors
Active solar design storage devices
Water for water systems
Rock beds for air systems
Phase-change materials can be used but are costly
Active solar design distribution systems
Ducts for air
Pipes for water
Associated fans, pumps, registers, and control devices
When solar energy is used for water the system may be
Open loop systems of closed loop systems
Open loop systems
Water is heated directly in the solar collector
Closed loop systems
Antifreeze or another transfer medium is heated in the collector and circulated to a heat exchanger, where the domestic water is heated by the transfer medium
When solar energy is used for space heating…
Either air or water can be used as the heat transfer medium
Geothermal
Uses ground-source heat pumps; electrically powered systems that work like air-source heat pumps but extract heat form the ground of give excess heat back into the ground; initial costs are high but long term costs are lower
Photovoltaics
The direct conversion of sunlight into electricity
Ideal angle of the sun
Varies slightly but approximately 15 degrees east of south
External load dominated building
Aka skin-load dominated building
Energy use is determined mainly by the amount of heat loss or gain through its exterior envelope
Generally have fewer people
Houses, apartments, condos, and warehouses
Building shape more important
Internal-load dominated building
Energy is driven by high heat gain from occupants, lighting, and equipment
Office buildings, hospitals, retail stores, schools, and labs
Building shape for cool/cold regions
Cubic shape
2 story house better than 1 story
Building shape for temperate regions
Shape has less of an effect
Elongated east to west has some advantages
Building shape for hot/arid regions
Squarer is better
External load should have courtyards
Internal load should be a solid multistory arrangement
Building shape for hot/humid regions
Elongated east/west orientation to allow breezes
Courtyards and broad overhangs
Insulation R-values
Prescribed in building codes or energy codes
Insulation
Usually must be installed with a vapor barrier to be effective
HCFCs should not be used
CFCs already phased out
Superinsulation
the technique of providing higher levels of insulation than normally used, tightly sealing all joints and cracks, and preventing any thermal bridges between inside and outside; electrical outlets are usually placed on inside walls or inside the insulation
Transparent Insulation
has a thick layer of polycarbonate honeycomb material, acrylic foam, or fiberglass sandwiched between layers of glazing; admits light while providing high degree of insulation; not used for a view
Movable Insulation
usually used on windows that provide passive sola heating; removed during sunlight hours and replaced at night or on cloudy days to prevent heat loss; manually, power or automated operation; roll-down shutter, insulated shades or curtains, swinging panels of insulation, and expanded polystyrene beans blown between panes of glass
Stack effect (chimney effect)
a difference in pressure between the top and bottom of a building due to a temp difference; most pronounced in a high-rise
Permeance
a measure of hour readily a material or membrane allows vapor to pass through it; the unit is perm which is one grain of moisture per hour per square foot per inch of mercury difference in vapor pressure
Air barrier should generally be located where
behind the exterior cladding and outside the sheathing; if both air and vapor barrier, place outside the structure and sheathing but within the building envelope
Earth sheltering
Soils should be granular: gravel , sand, or sandy loam
Test site for radon
Groundwater level must be below building
Extensive green roofs
use soil less than 6”D, meadow grasses, sedums, herbs, and perennials
Intensive green roofs
use deeper soil of 12” or more to support complex landscapes
Reflective roofing/cool roofs
Must have reflective value of 0.65 when new, 0.50 at 3 years
Used in climates where cooling days outnumber heating days
Solar heat gain coefficient
the amount of solar radiation that is transmitted through the entire window assembly, expressed as a fraction of the total amount that strikes it; a decimal fraction between 0 and 1; a value of 1 indicates a window assembly that lets all solar radiation pass through; value of 0 indicates a window assembly that lets none pass through; includes the frame, glass spacer, and other parts of the assembly
Shading coefficient
applies to just the glass itself; the ratio of the amount of solar radiation that passes through a piece of glass to the amount that would pass through a similar piece of unshaded, clear, double-strength glass ⅛” thick under the same conditions; a decimal fraction between 0 and 1
Insulating Glass (double glazing, double-pane glass, or triple-pane glass)
used to control heat loss; 2 or 3 panes are separated by sealed air spaces or partially evacuated spaces that act as insulators; U-values decrease to 0.57 Btu/ft2-hr-Fdeg if the panes are ¼” apart; heat loss by convection still occurs; solar heat gain loss by radiation; air can be replaces by Argon gas or Krypton gas
Tinted glass, reflective glass, and heat-absorbing glass
can reduce solar heat gain, but can also reduce the visible light traansmittance; cannot use solar heat gain
Low-E Glass
double glazing with a thin film places in the glazing cavity; efficient at preventing heat loss
Spectral selective glazing
transmits a high proportion of visible solar spectrum but blocks up to 80% of the heat; good in long cooling season ant where high interior light levels are needed
Super windows
glazing units that combine 2 low-e coatings with gas filled cavities between 3 layers of glass; can gain more thermal energy than they lose in 24 hours
Switchable glazing (chromogenic window)
change their characteristics based on particular environmental conditions or through human intervention
Double envelope
The outer skin consists of 2 glazed layers that are typically separated by 2-3ft; sun control (lovers, blinds, shades) and a passive or active ventilation system is incorporated into the space
Dynamic buffer zone system
When a new outer layer is added to an existing building (double envelope)
Daylight factor
the ratio of the illuminance at a point on a horizontal surface indoors to the illuminance at a point on a horizontal surface outdoors and fully open to the sky, measured at the same time under overcast skies; direct sunlight is excluded; expressed as a percentage
Daylighting building design
to ompimize dalighting the building portion should be long and narrow with. Long direction running east-west
deep facade can provide space for shading devices and light shelves
surfaces on the exterior should be light to reflect
high ceilings
Daylighting window design
Windows should be as high as possible
te effective daylighting zone extend 1.5 times the window head height into the room; with a light shelf it is extended 2-2.5 times the window head height
Effective aperture (EA) is the products or visible light transmittance and window-to-wall ratio
Visible light transmittance is the percentage of visible light that passes through a glazing material
window-to-wall ratio is the net glazing are in a room or space divided by the gloss exterior wall area not including window frames and mullions
small windows have low WWRs and large windows have high
if the glazing has low VLT the size of the window should be increased
Daylighting glazing selection
Glass with a low U-value is desirable for controlling heat loss through convection
glass with a low SHGC is desirable for controlling heat gain from sun’s radiaiton
glass with a VLT of 50-70% and lowest possible SHGC is good to control glare
Daylighting room design
High reflectance, min should be 80% for ceilings, 50-70% for walls, and 20-40% for floors
Effective height
the distance from the top of the barrier to the point where the acoustical line of sight intersects the barrier
If close to the noise, the barrier should be how high
4x as high as the distance from the source of the noise
How should evergreen trees and shrubs be planted for sound
Densely, 100’ deep or more
What sites should not be developed
sites designated as prime farmland, in floodplains, on or within 100’ of wetlands, on land designated as habitat for threatened species, or on land previously used as public park
Potable water
Has been treated to make it suitable for drinking
Rainwater
Natural precipitation
Gray water
Wastewater that is not from toilets and urinals, like from sinks, showers, bathtubs, and clothes washing machines
Blackwater
Water containing toilet of urinal waste, kitchen sinks, and laundry facilities
Protect existing watersheds
Erosion control during construction
silt fences, sediment traps or basins, vegetated buffer strips, hay bales, and other methods are used to control water flow and pollutants onto adjacent property, and into natural waterways
Catchment area
the area of the roof or other surface shedding the water into the water collection system
Gray water recycling
when recycled may be used for irrigation, toilet flushing, vehicle washing, janitorial cleaning, cooling, and similar uses
can also be run through a heat exchanger to heat up potable water
Blackwater recycling
Not cost effective and treatment is extensive
Toilets may not use more than
1.6 gallons per flush
Low flow fixtures are recommended
Life Cycle Assessment
Evaluates the environmental impact of a material or product in a building
4 phases to an LCA
Define the goal and scope of the study
Perform an inventory analysis
Perform an impact assessment
Perform an improvement analysis and report the results of the study
4 main stages in a product’s life cycle
Raw Material Acquisition
Manufacturing
Use and Maintenance
Disposal
For whole building life-cycle assessments, the building should be modeled as what?
A base case and design case; do not include interior conditions or site work, limited to structure and enclosure
Base case
Reflects the typical construction practices for buildings of that type, size, and location
Design case
Reflects the building’s actual construction
For LEED credit, the design case must outperform the base case in at least 3 of 6 categories
global warming, ozone layer depletion, acidification, eutrophication, formation of ground level ozone, and depletion of non-renewable energy resources
Acidification
generation of waste materials that can lower the pH of surrounding waterways or soils
Eutrophication
formation of excessive nutrients in a body of water that promotes increased algae growth
Environmental Product Declarations
A standardized report of a product’s environmental impact throughout its life cycle; based on info from LCA but give additional info and is verified by a third party
5 step process to develop EPD
- an applicable PCR is found or developed in accordance with ISO 14025
- the manufacturer conducts and independently verifies an LCA
- the EPD is prepared
- the EPD is submitted to an independent third party for review and verification
- if approved, the EPD is registered and published
Criteria for evaluating building materials
Embodied energy
Renewable materials
Recycled content
Energy efficiency
Use of local materials
Durability
Low volatile organic compounds
Low toxicities
Moisture problems
Water conservation
Maintainability
Potential
Reusability
Embodied energy
material or product should require as little as possible energy use for extraction, processing, manufacturing and fabrication as well as transportation
Renewable materials
a material that can renew the source within a short amount of time; wool, bamboo, straw, cotton, linoleum, polar OSB, sunflower seed, wheatgrass
Recycled content
less energy and raw materials; post consumer materials, post-industrial materials, recovered materials
Energy efficiency
materials, products, and assemblies should reduce the energy consumption in a building
Use of local materials
supports region’s economy, reduces transportation costs, add to regional character of design
Durability
last longer, less maintenance; higher initial cost
Low VOC content
can be released in indoor air and cause health risks; paint, carpet, composite wood products
Low toxicity
materials should emit low or no harmful gases, such as chlorofluorocarbons (CFCs), formaldehyde, etc
Moisture problems
should prevent or resist the growth of biological contaminants
Water conservation
reduce water consumption in building or site
Maintainability
should be easy to clean and maintain
Potential
for reuse and recycling
Reusability
a salvaged material in the life cycle of another building
Concrete per sustainability
-Not sustainable but has long life, heat storage capability, no appreciable emissions after curing, lower embodied energy than steel
-can be recycled for road use
-concrete used natural resources, cement has additions that are not natural/easily renewable
-reduce environmental impact with addition of fly ash, recycled aggregates, and low-waste formwork
-autoclaved aerated concrete: lightweight precast concrete made with aluminum powder; needs less cement than concrete
Masonry per sustainability
-Require large amounts of energy and raw material
-brick and CM’s usually made close to the project location and with local materials
-can be recycled
-can use fly ash, recycled aggregates, and lightweight aggregates
Metals per sustainability
-Large amount of energy for production but high potential for recycling
-electroplating and other chemical coatings/platings produce high levels of pollution and by-products; alternatively powder coatings and plastic polymer coatings can be used
Wood per sustainability
-Use reclaimed wood; specify sustainable or alternate materials; use certified wood products
-Forest Stewardship Council: a forest certification group; oversees the development of national and regional standards based on basic forest management principles and criteria; accredits certifying organizations; FSC uses 10 basic principles to available organizations for accreditation
Plastic per sustainability
-bioplastics/polylactide (PLA): a biodegradable plastic derived from corn; carpet fibers
-metallocene catalysis polymerization: a process that makes it possible to manufacture polyolefins with specific properties
Thermal insulation per sustainability
-Plastic based insulations are not recommended even if they are efficient
-Use instead:
+Cellulose insulation
+compressed straw
+cotton insulation
+glass fiber insulation
+mineral-fiber insulation
+spray-on cellulose
+perlite
+vermiculite
Finishes per sustainability
Recycled content and low VOCs for sustainability
Adhesives per sustainability
-Adhesives or coatings used during installation affect indoor air quality
-3 types are low-emission and zero-VOC:
+dry adhesives
+water-based adhesives
+natural adhesives
Flooring/carpet per sustainability
-Carpet good raw materials: polyester and nylon blended carpet made with recycled soft drink containers (PET) and wool
-Carpet cushions made from recycled tire rubber and synthetic and natural fiber from textile mill waste
-Carpet cannot be recycled easily; carpet tiles are more environmentally friendly than broadloom
-Carpet and Rug Institute test carpets for 4-type of emissions
Vinyl/rubber/linoleum per sustainability
-vinyl flooring is durable, easy to clean, relatively low cost, and has a lot of design options but is not environmentally friendly and is not easily recycled
-rubber flooring made from recycled tires is durable, slip resistant, and resilient; may emit indoor pollutants; only used where there is sufficient ventilation
-linoleum is made from natural, renewable products, is durable, biodegradable, waterproof, fire resistant, naturally antibacterial, and does not generate statis electricity
Cork and wood flooring per sustainability
-Cork flooring is made from renewable resource, sound absorber, warm texture, cushioned walking; prone to scratching and indentation; has to be imported
-wood flooring is a sustainable option; use prefinished wood materials when possible
-bamboo or palm wood is an alternative to standard wood floors, fast growing, palm wood from coconut plantations as a byproduct
Ceramic tile flooring per sustainability
ceramic tile considered sustainable even though a lot of energy is used; uses natural materials, durable, no harmful emissions, little maintenance; 100% recycled products available
Wall finishes per sustainability
-Gypsum wallboard made with 100% recycled content for paper face and some recycled content in the core; synthetic gypsum used sometimes (a product created from the process of removing polluting gases from power plant stacks); adhesives and caulking for installation can emit; not easy to recycle
-Sisal wall and floor coverings is made from the fibers of the sisal plant; rough and not for wet areas, durable, low maintenance, reduce sound
-Paints must conform to VOC limits set by the EPA
Ceiling finishes per sustainability
-Tiles of recycled content of old tiles, newsprint, or perlite is available
-tiles can be repainted if done correctly
-some manufacturers accept old tiles for recycling
Furnishings per sustainability
-Particleboard, MDF, and coatings can have formaldehyde
-specify powder coated finishes instead of paint
-specify that cushions be formed with CO2-injected foam or other environmentally friendly materials
Indoor air contaminants can be classified into 2 groups
Chemical contaminants
Biological contaminants
Chemical contaminants
include substances such as volatile organic compounds, inorganic chemicals, tobacco smoke
Biological contaminants
include mold, pollen, bacteria, and viruses
VOCs
chemicals that contain carbon and hydrogen and that vaporize at room temp and pressure; likely in paints, stains, adhesives, sealants, water repellants and sealers, particleboard, furniture, upholstery and carpeting; regulations for VOCs in coatings
4 main causes of poor indoor air quality
- chemical contaminants from indoor sources (most common)
- chemical contaminants from outdoor sources (can happen when air intake vents, windows, or doors from parking garages are badly placed or exhausts and plumbing vents from inside are too close to air intakes)
- biological contaminants (moisture infiltration, standing water, stagnant water from mech equip, or insect/bird droppings)
- poor ventilation (balance ventilation with energy conservation)
3 classifications of poor indoor air quality symptom
Sick building syndrome
Building related illness
Multiple chemical sensitivity
Sick building syndrome
a variety of symptoms not directly related to any one cause
Building related illness
a symptom that can be directly related to a specific building contaminant
Multiple chemical sensitivity
from exposure to VOCs or other chemicals; sensitivity to the chemicals
5 categories for maintaining good indoor air quality
- Eliminate or Reduce Sources of Pollution
- Control Ventilation
- Establish Good Maintenance Procedures
- Control Occupant Activity
- Provide Appropriate Filtration
Indoor Air Quality Standards
- Clean Air Act of 1970
- ANSI/ASHRAE Standard 62.1 Ventilation for Acceptable Indoor Air Quality
- National VOC Emission Standards for Architectural Coatings
- GREENGUARD Certification
- ASTM D5116 Standard Guide for SMall-Scale Environmental Chamber Determinations of Organic Emissions from Indoor Materials/Products
- ASTM D6670 Standard Practice for Full-Scale Chamber Determination of Volatile Organic Emissions from Indoor Materials/Products
- ASTM E1333. Standard Test Method for Determining Formaldehyde Concentrations in Air and Emission Rates from Wood Products Using a Large Chamber
Asbestos
Naturally occurring fibrous material found in certain types of rock formations
banned in 1989
Vermiculite
Silicate that resembles mica; used for our-in insulation, acoustic finishes, fir protection, and sound deadening; may be contaminated by asbestos
Lead
Highly toxic metal; from paints before 1978
Radon
Colorless, odorless, tasteless, naturally occurring radioactive gas found in soils, rock, and water
Polychlorinated Biphenyls (PCBs)
Mixtures of synthetic organic chemicals with physical properties ranging from oily liquids to waxy solids; used in building transformers, fluorescent light transformers, paints, coating, and plastic and rubber products
banned in 1977
Life Cycle Cost Analysis
Not the same as and LCA (Life Cycle Assessment)
A method for determining the total cost of a building, building component, or system over a period of time; takes into account the initial cost and the costs of financing, operation, maintenance, and eventual disposal
Residual value
the remaining value of the element at the end of the study period based on resale value, salvage value, value in place, or scrap value
Life cycle cost analysis process
costs are estimated, discounted to present value, and added together. Residual value is discounted to present value and then subtracted from the total to determine the final life-cycle cost of the element
Sustainable Building Programs, Rating Systems, and Standards
Building Research Establishment Environmental Assessment Method (BREEAM)
Collaborative for High Performance Schools (CHPS)
Section 01350
ENERGY STAR Buildings and Plants
Green Globes
Leadership in Energy (LEED)
National Green Building Standard
WELL Building Standard
