BIM to SIM: Trends in Buildings, Technologies and Tools

Drury B. Crawley, Ph.D., FASHRAE, BEMP, FIBPSA, AIABentley Systems, Inc.

2014 ASHRAE/IBPSA-USABuilding Simulation

Conference

Energy End Uses by Sector

Energy in Our Economy is Complex

Energy Use and Carbon Emissions are Down

U.S. Buildings’ Energy Use

Energy Information Administration. 2013. Annual Energy Outlook 2013, EIA-0383 2013). Washington, D.C.

Building Industry Trends

• Centralization of Ownership (large chains, owners)• Worker Health / Productivity / Comfort• Continuous commissioning, ESCOs, utility programs• Price shocks, energy deregulation • Climate change mitigation / carbon regulation • Green buildings• BIM• Benchmarking/Data!• NZEB/NZEC

Policy Drivers – Buildings Are Getting Better

• Economic and environmental drivers • Mandatory performance metrics: national and local codes and

standards… but are they enforced?• Voluntary performance metrics (LEED, BREEAM, BEPAC, many others)• National and international policy

• Climate Change but what are nations doing?• Kyoto Protocol• EU began mandatory building performance labeling in 2009 (EPD) …

• US energy policy continues to be voluntary approach, with mandatory minimum standards

New Technologies: Available Now or Soon to Hit Market

Technology Penetration is Accelerating

Technology Change in 20 Years

New Technology – SSL and OLED

Lighting is undergoing a revolution: LEDs use much lower energy with expected life of years (decades?). New forms (no longer restricted to Edison shape lamps, 4 ft fluorescents)

26

Parking Lot Lighting – 50% Savings Today

Photovoltaic Power

Fuel Cells, Microturbines, DHCP, DC

Increased Stringency in Standards 90.1/189.1

0

10

20

30

40

50

60

70

80

90

100

110

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Ener

gy U

se In

dex

(197

5 U

se =

100

)

Year

14% Savings 4% Savings

11% Savings

Standard 90.1-2010

Standard 90-75 Standard 90A-1980

Standard 90.1-1989

Standard 90.1-1999

Standard 90.1-2004

Standard 90.1-2007

Standard 90.1-2013

Standard 189.1-2009

Standard 189.1-2011

Source: DOE Building Energy Codes Program

End-Use Energy: More Details are Better!

Total Equipment

28%

Total Lights13%

Total HVAC59%

Reference: Pless and Torcellini. 2004.

Building Performance Simulation

• Simulation is still more art than science• Major Challenges:

• Building data maintenance/storage throughout building life-cycle• Training...must train users in simulation methods not tools!• Tools must enable and encourage new technologies--too many

technologies/systems that various tools cannot simulate

• Getting geometry and other data from existing building information models (yes, BIM) is a significant challenge.

• Green/sustainable design and policy are driving simulation more than energy costs (LEED, IgCC, EPC, Title 24, ASHRAE 90.1/189.1, IECC)

• New tools/capabilities in established tools• Interoperability—IAI IFC, XML, BIM Standards• Visualization/VR• Cloud• Integration—thermal, CFD, electrical, IEQ, visual• Risk assessment (insurance)• Embodied energy, LCI/LCA, toxicity of built environment• Emissions

• More tools, not fewer, customized to user needs• Users continue to want more at lower effort

WARNING! Do you know what default values you’re using?

Simulation Trends

Traditional SimulationWorkflow Challenges

• Early design through construction documents – with increasing detail, multiple solutions

• Existing buildings with no details (maybe no drawings?)

• Manual input, data re-creation, translation errors and omissions

• Utilizing virtual data (2-D CAD, BIM) geometry robust, other data limited

Nall and Crawley 2011

Building Information Model/Modeling

• Building Information Model:• Digital representation of physical and functional characteristics of a

facility. . . shared knowledge resource for information about a facility, forming a reliable basis for decisions during its life cycle from inception onward.1

• Building Information Modeling:• Using BIM software and other related software, hardware and

technologies in a building information model2

1 National Institute of Building Sciences (NIBS). 2007. National Building Information Modeling Standard Version 1, Part 1, p. 21.

2 Jernigan, F. 2007. BIG BIM little bim, The Practical Approach to Building Information Modeling, Integrated Practice Done the Right Way! Salisbury, Md.: 4Site Press.

Information Mobility

BIM Today is NOT Your Father’s CAD

BIM to Sim(ulation)

• Translate BIM to Simulation• BuildingSMART IFCs (Industry Foundation Classes)

• Any BIM software that supports interoperability, available since 2001• Limited to what BIM tools decide to export—typically only geometry

• gbXML• Autodesk Green Building Studio

• Web-based conversion of major BIM formats to energy simulation inputs• Limited coverage• Can require users to create their BIM drawings in structured way

(may not follow designer regular workflow)

• Direct from BIM to Simulation• Major tools already have or are adding direct export to one or more simulation tools

• Interoperability is key to getting energy simulation mainstream. Other drivers—zero-energy buildings and green building rating systems

“Every building is a forecast. Every forecast is wrong.”

Stewart BrandHow Buildings Learn, What Happens after they’re Built

• Simulation critical in supporting decision-making for building design and operation of low- and zero-energy buildings

Simulation vs. Operating Energy

• BUT, compared to simulations, real buildings– use more energy – produce less power– have worse controls – have more occupant

complaints– GIGO– Not enough information!

Summary

• Changes in building technologies over the next several decades will be significant—driven by:

• Policies (EPD, labeling, carbon regulation, energy standards)• Demand for better buildings from building owners and occupants

• Energy and Green Standards are already pushing significant reduction in energy performance. Increasingly difficult to comply with prescriptive requirements (already 25-30% increased stringency)

• Quality of simulation results only as good as the data entered: GIGO – the more data about the building and how it works, the better.

• Getting data from BIM to Sim through interoperability still a significant challenge – often incomplete, blackbox defaults, insufficient for simulation.

• Interoperability among building software tools will accelerate use of building simulation. Is there enough demand for interoperability to push the software developers?

So, Is This the Building of Tomorrow?

Probably More Like NREL RSF (NZEB)

Or These Recent Buildings

Or Even Apple’s New HQ

EnergyDemand

Cost

WaterIEQ

Carbon

Business(student, occupied room, sales)

Challenge: Provide Clients with Multiple Metrics

Thank you!

Dru CrawleyDru.Crawley@Bentley.com