autodesk webinar urban design

© 2008 Autodesk

Autodesk® Ecotect® Analysis 20113. Sustainable Sites and Green Urban Planning

Emanuele Naboni MArch, PhD Building Science, LEED AP, EU licensed architect,Associate Professor in Climate Architecture / Royal Danish AcademySustainable Design Consultant / www.e3lab.orgemail: [email protected]

® Emanuele Naboni

© 2008 Autodesk

Speaker: Emanuele Naboni

® Emanuele Naboni

Current - Associate Professor in Climate Architecture, Royal Danish Academy – Copenhagen2005-09 Lawrence Berkeley National Laboratory (Researcher)2007-09 Skidmore, Owings and Merril (Performative Design)2006 LEED AP2003-2006 PhD in Building Science, Politecnico di Milano & University of California2002 Master in Architecture [email protected]

© 2008 Autodesk

The Earth's major source of heat and light, the sun, also creates the secondary climatic elements of wind andhumidity that affect physiological comfort. These are caused by the configuration and nature of the local surface,such as the mountains, plains, oceans, deserts, and forests. The interplay between this astronomical source ofenergy with the effects it causes and the landscape creates the microclimate, which is the concern of thescience of meteorology. Hassan Fathy

Architectural design for a comfortable microclimate– the Earth

© 2008 Autodesk

However, the built environment produces changes in the microclimate. The configuration of buildings, theirorientations, and their arrangement in space create a specific microclimate for each site. To this must be addedthe building materials, surface textures and colors of exposed surfaces of the buildings, and the design of openspaces, such as streets, courtyards, gardens, and squares. These man-made elements interact with the naturalmicroclimate to determine the factors affecting comfort in the built environment: light, heat, wind, and humidity. Hassan Fathy

Architectural design for a comfortable microclimate– the Built Environment

© 2008 Autodesk

336cities worldwide with more than 1 million residents

Million+ cities today

Green Urban Planning

© 2008 Autodesk

Tokyo 35mJakarta 22mNew York 20mSeoul 20mMumbai 19.5mSão Paulo 19.2mMexico City 18.5mDelhi 18mOsaka 17.3mShanghai 16m

World’s 10 largest cities


© 2008 Autodesk

50mpopulation of the pearl river delta

amalgamations of multiple cities into one

Megalopolises


© 2008 Autodesk

From “Design with Climate”, Olgyay, 1963

® Emanuele Naboni

Green Urban Planning and Climate

© 2008 Autodesk

A sustainable city, or eco-city is a city designed with consideration of environmental impact, inhabited by peoplededicated to minimization of required inputs of energy, water and food, and waste output of heat, air pollution - CO2, andwater pollution. Although the process of growing of the cities can’t be stopped the measures must be taken to minimize the energyconsumption. Architecture and town planning must become instruments for creating harmony between cities and natural environment.

Sustainable city

© 2008 Autodesk

water

energy

environment

daylightingOutdoorcomfort

sustainability

Form and fabric

lowcarbonurgency

materials

Buildingperfomances


© 2008 Autodesk

Ecotect: Building Performance at Urban Scale

§ Use shadows to protect building when needed to avoid overheating (Ecotectshadows calculations)

§ Consider Energy Implications in Site Selection and Building Orientation (Ecotectcalculated best orientation)

§ Optimize building compactness (Ecotect thermal calculations)

§ Orient building massing to be able to integrate passive and active solar strategies inbuildings (Ecotect solar radiation studies)

§ If renovating/retrofitting an existing structure (i.e. when employing passive solarstrategies is not possible), consider planting trees to shade areas of the buildingthat get more sunshine.

§ Take advantage of natural ventilation and prevailing wind patterns, or protect formthem depending on the climate (Ecotect Weather Tool)

§ Maximize dayllight use. (Ecotect daylighting Analysis)

§ Use reflected light to increase daylighing levels when needed (Radiancecalculations)

§ Investigate the potential impact of future adjacent developments to the site (e.g.,solar and wind exposure, daylighting, ventilation, etc.).

© 2008 Autodesk

Ecotect: Outdoor Spaces Performances

§ Control DIRECT SOLAR GAIN in the streets. (Ecotect shadows diagrams) This willmean calibrate street openings, shading or expose the streets

§ Provide oravoid ventilation (Ecotect Weather Analysis Tool)

§ Achieve daylighting by reflectance

§ Balance material properties, thermal absorbtion and light reflectance (EcotectDaylighting Analysis)

§ Reduce Heat Islands Using Landscaping and Building Design Methods, useopposite strategies for cold climates(Ecotect absorbed radiation analysis)

§ Maximize the use of existing trees and other vegetation to shade walkways, parkinglots, and other open areas. (Ecotect absorbed radiation analysis)

§ In hot-dry climates, compact planning with little or no open spaces would minimizeheat gain This is how traditional settlements were often planned.

§ Consider incorporating green roofs or photovoltaics into the project. (Ecotect PVmodules calculations and absorbed radiation analysis)

© 2008 Autodesk

Sustainable Sites and Green Urban Planning

® Emanuele Naboni

Green Urban Planning with EcotectSustainable City DesignCase Study: Royal Danish Academy CampusPattern and Outdoor Space PerformancePattern and Building PerformancesThe Solar Enevelope concept with EcotectUrban ShadingRight to Light AnalysisSurface / Volume Ratio optimizationVisisbility calculationActive Design and Photovoltaic Studies 1

© 2008 Autodesk

® Emanuele Naboni

Royal Danish Academy Campus

© 2008 Autodesk

Royal Danish Academy Campus

© 2008 Autodesk

Cold Areas Bio-Climatic Urban Design

§ The general RULES that govern Cold Climate Design are:

§ create a sheltered MICROCLIMATE to make it LESS cold. If you design the site tocapture the sun and buffer it from winter winds, it will make the local temperaturesand conditions easier for the building to respond to.

§ Maximize daylighting for both urban spaces and buildings

§ Material should be choose as a balance between heat collection and light reflectivity

§ ORIENT AND SITE THE BUILDING PROPERLY FOR THE SUN. If the buildingscannot receive free heat from the sun due to the orientation of its glazing away fromthe sun, then this will be a problem.

§ maximize south facing facades for easier control. When we look at solar angles inthe Passive Design powerpoint, you will see that south facing windows arepreferable, both for the amount of free energy that they can provide, as well as theease of shading them in the summer months when we wish to exclude unwantedheat from our building interiors.

§ East and West facing windows are more difficult to control for solar issues. Northfacing windows do not benefit from solar gain, and result mostly in heating lossesthrough the envelope.

© 2008 Autodesk

Solar Access

© 2008 Autodesk

Better solar access is possible with east-west street sections as the south face of the building will get sun formost of the day. Street spacing is adjusted so that the buildings do not block each other’s south light when theangles are lowest in the winter (for good design).

Solar Access

© 2008 Autodesk

When working with street layouts that have adominant north-south street orientation, duringthe morning and afternoon hours, particularly inthe winter months, the street level and lowerlevels of opposing buildings are often in theshade.This is only alleviated by making very widestreets.

Solar Access

© 2008 Autodesk

North-south canyon effect at Bain Avenue Coop, Toronto

® Emanuele Naboni

© 2008 Autodesk

Acoma Pueblo, New Mexico, looking northeast. Terraces,windows and doors face southward to capture the wintersun. (Drawing by Gary S. Shigemura in Energy and Form by Ralph L. Knowles.)

© 2008 Autodesk

Solar envelopes (left) replaced by design (right)copyright: Ralph L. Knowles, 1999

© 2008 Autodesk

Solar Access – Right to light

© 2008 Autodesk

Solar Envelope

© 2008 Autodesk

Solar Envelope’s right to light

© 2008 Autodesk

Solar Envelope replaced by design

© 2008 Autodesk

Shadows – winter optimum

© 2008 Autodesk

Solar Envelope butterfly diagramDecember 21st

© 2008 Autodesk

Shadows – December 21 – Shadows at 12:0001 RD solar envelope-right to light analysis

© 2008 Autodesk

Shadows – December 21 – Butterfly Diagram01 RD solar envelope-right to light analysis

© 2008 Autodesk

Shadowing, overshadowing and Sunlight Hours

© 2008 Autodesk

The Comfort Zone refers to therange of temperature conditions ofair movement, humidity andexposure to direct sunlight, underwhich a moderately clothed humanfeels “comfortable”.This will be different for Indoorversus Outdoor conditions.These will be different for differentCLIMATE types.

As Architects we use our buildings tonot only create comfortable indoorenvironments, but also pleasing anduseful spaces outside of our buildings.

Comfort zone

® Emanuele Naboni

Image from MIT – Maryline Anderson

© 2008 Autodesk

This famous illustration istaken from “Design withClimate”, by Victor Olgyay,published in 1963.

Comfort Zone

® Emanuele Naboni

© 2008 Autodesk

Carbon Reduction: The Tier Approach

Image: Norbert Lechner, “Heating, Cooling, Lighting”

© 2008 Autodesk

Reduce loads: Passive Strategies

The tiered approach to reducing carbon for HEATING: Maximize the amount of energy required for mechanical heating that comes from renewable sources.Source: Lechner. Heating, Cooling, Lighting.

Tier 1

Tier 2

Tier 3

Maximize HeatRetention

Passive Solar Heating

Mechanical Heating

© 2008 Autodesk

Reduce loads: Passive Strategies

The tiered approach to reducing carbon for COOLING: Maximize the amount of energy required for mechanical cooling that comes from renewable sources.Source: Lechner. Heating, Cooling, Lighting.

Tier 1

Tier 2

Tier 3

Heat Avoidance

Passive Cooling

Mechanical Cooling

© 2008 Autodesk

Reduce loads: Daylighting

The tiered approach to reducing carbon withDAYLIGHTING: Use energy efficient fixtures!Maximize the amount of energy/electricity required for artificial lighting that comes from renewablesources.Source: Lechner. Heating, Cooling, Lighting.

Tier 1

Tier 2

Tier 3

Orientation andplanning of buildingto allow light to reachmaximum no. ofspaces

Glare, color, reflectivity and materialconcerns

Efficient artificial Lighting w/ sensors

© 2008 Autodesk

Different types of buildings an the same territory to build the same 75 tenements (“R. Rogers and partners” studio)

Types of Built up territoriesAspect Ratio: what’s best?

© 2008 Autodesk

Aspect Ratio: what’s best?

London City Hall, studies, Norman Foster

© 2008 Autodesk

Aspect Ratio: What is best in Copenhagen?

© 2008 Autodesk

Solar Envelope ConsumptionsS/V = 0.30

© 2008 Autodesk0

Webgis Comune di Laives

© 2008 Autodesk

Whatever the FOUND condition ofthe site upon which we are toconsider building has a climate thatis not only dependent upon thegeneral climate of the REGION, butalso, the specific climate of the siteas affected by:- the surface or surfaces that coverthe ground- available tree cover, size, height,biodiversity, species, etc.- nearness to water- amount of paving adjacent- height of adjacent buildings

Institute of Contemporary Art, Boston

® Emanuele Naboni

Micro-climate

© 2008 Autodesk

When we design WITH the specificlocal environmental characteristics inmind, we start to manipulate therelationship between the climate, thesite and the building to create a localenvironment or MICROCLIMATEaround the building. This “mini climate” that is createdaround the building can decrease theapparent severity of the climate (andhence the work the building must doto make for a comfortable interiorAND exterior environment around thebuilding) OR, if badly handled, canincrease the severity of the localclimate.

St. Thomas University, Houston

Micro-climateMicro-climate

® Emanuele Naboni

© 2008 Autodesk

1. Use maximum solar exposures2. Provide for paved and masonry surfaces on south side of site.3. Provide vegetational canopies to reduce night cooling.4. Encourage “sun pockets” on site.5. Make windbreaks with vegetation or fence like enclosures.6. Remove shading devices during the day (or winter).7. Use heat-retaining materials such as concrete or masonry.8. Locate outdoor terraces for afternoon in the south or southwest.

Temperature Guidelines:Cold City: How to make a site Warmer?

© 2008 Autodesk

1. Make extensive use of shade trees as an overhead canopy.2. Use vines, on trellis, or canopies on south and west facing walls.3. Use trellises, overhangs -- this also limits heat loss at night.4. Use ground covers or turf on earth rather than paving.5. Prune lower branches of trees and reduce close shrubs to encourage air circulation.6. Provide for evaporative cooling from water elements.7. Use areas on north and east of building for outdoor activities.8. Remove windbreaks which would limit airflow during warmer months.

Temperature Guidelines:Warm City: How to make a site Cooler?

© 2008 Autodesk

1. Allow standing water to stay on site and limit drainage.2. Encourage overhead planting which slows evaporation and provides moisture from the plants.3. Add water elements such as fountains. Also helps from sound of water.4. Use turf or ground cover instead of paving.5. Use low windbreaks (below 1.2m) to preserve moisture transpired by surf or ground cover.6. Use natural wood chip or peat mulch under all plantings.

Humidity Guidelines:Dry Climate: How to make a site more humid?

© 2008 Autodesk

1. Maximize solar radiation exposure on site and reduce shading devices.2. Maximize airflow and ventilation across the site.3. Provide an efficient water drainage system for groundwater and storm drainage.4. Pave all horizontal ground surfaces.5. Reduce planting, especially ground covers and turf.6. Eliminate all water bodies, pools and fountains.

Humidity Guidelines:Humid Climate: How to make a site drier?

© 2008 Autodesk

Incident Insulation Analysis - Whole Year

© 2008 Autodesk

§ The precise condition of the sky istaken into account whendetermining the amount of solarradiation that is received by abuilding.

§ The clearer the sky, the moreenergy received.

Incident Insulation Analysis

© 2008 Autodesk

Urban Heat Island

© 2008 Autodesk

Albedo

§ "Albedo" or reflectivity is the ratio of the amount of lightreflected from a material to the amount of light shone on thematerial.

§ In the case of pavements, a lower Albedo suggests that moresunlight in absorbed by the pavement.

§ This sunlight is converted into thermal energy and thepavement gets hotter.

§ Pavements with higher albedo collect less energy and are thuscooler.

© 2008 Autodesk

Albedo Ranges

Albedo ranges of various surfaces typical to urban areas.[Sources: NASA, Akbari, and Thayer]

© 2008 Autodesk

Materiality and Site

© 2008 Autodesk

Microclimate and Site Materials

Microclimate is the “mini climate zone” around your building as modified by localconditions.

Things that naturally change your microclimate are:§ amount of sun received over the day§ wind and natural breezes§ The natural materials of the siteThings that YOU select also change the microclimate:§ material choices: paving, roofing, wall materials and planting§ colour of materials i.e.: In a cold climate select materials to:INCREASE HEAT in the WINTERDECREASE HEAT ABSORPTION in the SUMMER

® Emanuele Naboni

© 2008 Autodesk

[kWh/m2]

Solar Radiation

© 2008 Autodesk

Solar Radiation: Mapping Materials

© 2008 Autodesk

Incident Solar Radiation on Buildings

© 2008 Autodesk

Incident Solar Radiation

© 2008 Autodesk

Absorbed Radiation by Material - Summer

© 2008 Autodesk

Absorbed Radiation by Material - Summer

WITH GRASS ALL ASPHALT

© 2008 Autodesk

WITH GRASS ALL ASPHALT

Absorbed Radiation by Material – Winter

© 2008 Autodesk

Urban reflections

© 2008 Autodesk

§ URBAN REFLECTANCES of a space are governed by two primary surfacecharacteristics of the building materials – COLOR AND TEXTURE.

§ Color determines the quantity of light reflected by a surface. Dark-coloredmaterials absorb light while light-color materials reflect light.

§ Texture determines the quality of light leaving the surface after the reflection.Rough textured surfaces, referred to as matte, create diffused reflected light.Smooth or glossy surfaces create specular reflected light.

§ When lighting a urban space, diffuse light is preferable because specularsurfaces can lead to glare.

§ A larger space has more opportunity for interreflections (losses) than asmaller space

Urban reflections

© 2008 Autodesk

Form: ventilation

§ the form of the building has a significant impact on the abilityto ventilate a building using natural means

§ natural ventilation is achieved by two mechanisms: winddriven pressure and stack effect

§ when considering natural ventilation it is important toremember that the ventilation level is dependent upon windspeed and/or temperature and is therefore variable

© 2008 Autodesk

1. Use extensive windbreaks (plants, landforms, structures).2. Use outdoor living areas that are semi-enclosed by building or landscape.3. Do not prune or thin lower branches on tall trees.4. Locate outdoor activities in areas protected by natural windbreaks.5. Excavate and place activities partly below ground level in order to use the earth to block winds and requirelower windbreaks.

Wind Guidelines:Windy Climate: How to make a site less windy?

© 2008 Autodesk

1. Remove all obstructions to prevailing and predictable wind sources.2. Use plants and landforms to funnel and accelerate breezes.3. Prune all lower branches of taller trees.4. Curtail and limit low plant growth between 1 and 10 feet high which would obstruct wind flow.5. Locate outdoor activities in areas with maximum exposure to prevailing breezes.6. Build decks or platforms in areas exposed to breezes.7. Locate evening activities in cool air puddles or in sloped valleys to take advantage of airflow.

Wind Guidelines:How to increase wind flow and cooling?

© 2008 Autodesk

Form: natural ventilation

§ in low energy buildings the form is often engineered tomake best use of stack and/or wind driven ventilation

§ shallow plan (low driving force resistance)§ atrium (high/low openings + high low pressure)§ ventilation chimney (high/low openings + high low

pressure)

© 2008 Autodesk

Form: wind driven ventilation

§ air flowing over a building gives rise to natural pressuredifferences

§ creates pressure difference across the building façade – this isthe driving force for air flow

§ judicious placement of ventilation opening creates a naturalventilation scheme

low pressure

high pressure low pressure

© 2008 Autodesk

Form: wind driven ventilation

2

21)( fpbpa VccP ρ−=Δ

§ the available pressure difference between two surfaces of afaçade is given by

© 2008 Autodesk

Form: stack ventilation

§ this is driven by internal and external temperature differences§ occurs between openings at different heights§ as with wind pressure ventilation schemes the amount of

ventilation is variable

h

!"

#$%

&−−=Δ

int

11273

TThgP

ext

ρ

© 2008 Autodesk

Royal Danish Campus´ RoofsEcotect Photovoltaic Potential

34%

12%

44%

10%

PV Est

PV Sud

PV Ovest PV Nord

PV crystal

0

50000000

100000000

150000000

200000000

250000000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Decmonth

Wh

PV Est

PV Sud

PV Ovest PV Nord

© 2008 Autodesk

0

20

40

60

80

100

PV Est PV Sud PV Ovest PV NordRoof

% Winter

Summer

Royal Danish Campus’ RoofsEcotect Shading Coefficients

© 2008 Autodesk

050000

100000150000200000250000300000350000

solarenvelope

court court+greenhouse

tower

KWh

Form and Photovoltaic Collection

© 2008 Autodesk

0

20

40

60

80

100

PV Est PV Sud PV Ovest PV Nord-

% Winter

Summer

Solar Envelope’s RoofEcotect Shading Coefficients

© 2008 Autodesk

Emanuele Naboni MArch, PhD Building Science, LEED AP, EU licensed architect,

Associate Professor in Climate Architecture / Royal Danish AcademyAutodesk Sustainable Design Consultant

email: [email protected]

autodesk webinar urban design

Documents

town planning

comfortable microclimate

built environment

phd building science

building performance

mmexico city

autodeska sustainable

autodeskfrom design