It can be argued that industry’s use of computer simulation has not kept up with the potential contribution this technology can make to the design and construction of buildings.

We use the visionary South Australian Health and Medical Research Institute (SAHMRI) building as a case study of how dynamic thermal simulation (energy modelling) and daylight simulation methods can be optimally applied to enhance the environmental performance of a new building.

Computer simulation of a building’s environmental performance typically embraces three related but separate applications:

  • Dynamic thermal simulation of a building is the assessment of heat flows, internal thermal loads, and solar loads throughout a building to calculate achieved space temperatures and energy use
  • Daylight simulation refers to the calculation of daylight levels under typical conditions experienced at the site. Increasingly, the technique is being used to understand the risk of glare occurring for particular built-forms and facade properties
  • Computational fluid dynamics (CFD) calculates airflow and temperature patterns within individual spaces or in the surrounding external environment. While CFD is frequently used to demonstrate and improve building performance, the extensive wide-ranging capabilities of this tool are not discussed in this article.

How the potential of building performance simulation can be missed

Simulation is most commonly used for National Construction Code (NCC) and sustainable rating tool compliance.

In theory, simulations of this type can provide significant value to projects by freeing the designer from the constraints of Deemed-to-Satisfy (DtS) processes within codes and standards.

In practice, much of this potential value is lost because the analyses are undertaken well after the major design decisions have been made. The work becomes merely a validation of existing design rather than a tool for innovation or optimisation and fails to capture the full value of simulation.

Optimum use of simulation

The best value is obtained from simulation when it is used to inform all stages of building design and construction from concept through to post-construction.

The largest opportunity for built-environment designers is to use simulation to compare design decisions and opportunities during concept design. This requires buy-in from the whole design team, not just architects, in order to reach a common optimised goal.

Preliminary analyses can be used to inform key design decisions e.g:

  • Building siting, massing, layout and orientation for energy, daylight and external wind flows
  • Glazing size, shading and type for energy and daylight
  • Comparing different HVAC systems or central plant types for relative energy efficiency
  • Performance goal setting (e.g. NABERS, Green Star, Net Zero) or preliminary feasibility assessment

There are many software tools that can be used in early modelling.

According to a paper co-authored by Aurecon’s Quentin Jackson, there’s a wide range of opportunities for the use of simulation throughout the design and construction process.

Figure 1: Opportunities for the use of simulation throughout the design and construction process

Design Development – optimising systems

In design development, simulation has a myriad of uses informing the decisions of architects and engineers. Key opportunities include:

  • Detailed development and testing of glazing and shading design
  • Optimising insulation
  • Space design for daylight optimization
  • Right-sizing of mechanical plant
  • Design of more complex mechanical airflows
  • Natural ventilation through buildings
  • Testing efficiency options such as alternative mechanical systems and heat recovery
  • Optimising central plant sizing
There is extensive use of rule-of-thumb and spreadsheet calculations for preliminary equipment sizing. Such methods tend to routinely oversize plant items, causing unnecessary capital costs and poorer efficiency. The additional costs typically far outweigh the costs of simulation. Timely use of building simulation can also highlight other issues before design is finalised, saving time and money as well as optimising building performance.

Construction Documentation – optimising controls, documenting anticipated results

In construction documentation, the opportunities for changing design have largely passed, but simulation can still continue to add value through:

  • Testing and optimising control ‒ The energy efficiency and comfort of modern buildings is highly dependent upon control
  • Testing the full design against project goals ‒ The construction documentation phase is the last chance to simulate performance versus project goals. Late-stage design adjustments can be made
  • Testing compliance ‒ Many buildings will have NABERSGreen Star or NCC JV3 compliance requirements. Simulation models are needed to ensure that the final design delivers the required outcomes

Post-construction – verifying results

The use of simulation in post-construction performance verification is increasing, providing opportunities for improvement in control commissioning, tuning and modelling.

Case Study: SAHMRI

SAHMRI collaborated with Aurecon to complete the facade showing hood geometry. Photo by Peter Clarke.

Figure 2: SAHMRI completed facade showing hood geometry

Background

Although still not commonplace, a performance-based approach to simulation in the early building design stage can have impressive results. SAHMRI, and in particular its striking facade solution, is a product of performance-based design that balanced aesthetics, cost, and buildability, as well as environmental variables such as solar control, daylight availability, glare and thermal comfort.

SAHMRI is a 25 000 m2 research facility. Its design team included Woods Bagot, Atelier Ten, Cundall, NDY and Aurecon.

Key to the success of the design was developing quantifiable performance metrics upfront to allow robust testing of options between the environmental design consultant, Atelier Ten, and architect, Woods Bagot.

Fig 3 summarises the metrics and outcomes that could be impacted by the facade alone:

In a paper co-authored by Quentin Jackson from Aurecon, facades can have several impacts on building performance.

Figure 3: Impact of facade on building performance

Space versus energy planning

The first step of the facade optimisation process was to assess which space type required access to daylight and which spaces lent themselves to opaque elements. With the three-dimensionally curved form of the building and significant facade structural spans across multistorey atria, a triangular grid-shell solution was selected as the most appropriate facade system. Nine variations of exterior shading devices were simulated.

Regardless of the space type selected to sit behind a particular piece of facade, limiting direct solar gains was crucial in reducing HVAC plant size, energy consumption, risk of glare and improving thermal comfort.

However, the value of the simulation was in freeing the designers to select an external shading strategy optimised for cost and buildability rather than purely for energy savings.

Key comfort factor

With the facade significantly affecting thermal comfort, daylight and glare – the performance discussion focused on making an attractive, healthy workplace ‒ the Wellness factor for the occupants of this visionary building.

General comments on simulation

  • Quality assurance
    The phrase ‘garbage in, garbage out’ is as relevant to building simulation as to any other form of computing. The temptation is also ever present to accept results at face value leading to mistakes reticulating through to the final results without question.
  • Timing
    Time needed to create a simulation model varies widely. Some software tools, especially those designed for use during concept design, can provide peak load and energy consumption results instantaneously, once a 3D model has been created or imported; whereas a fully-detailed thermal simulation of a detailed design can take much longer. Once the base model is produced, design refinements and operational scenarios are typically quite easy and quick to produce.

Conclusions

Computer simulation gives design teams the opportunity to test building performance during the design process through to post construction. Correctly used, a simulation can return many times its cost to a project. However, often simulation is used purely for compliance with NCC JV3, Green Star or NABERS; this undervalues the simulation and wastes much of its value potential to a project.

Design teams should use simulation as an integral part of the design process to enable better design decisions to be made throughout the entire construction process.

This article is an abridged version of the original paper published in Environment Design Guide – EDG 91 NP October 2017. Reproduced with permission from The Australian Institute of Architects.

About the authors

Nicki Parker
Nicki has recently taken up the position of Norman Disney & Young’s Sustainability Manager for Brisbane after an 11 year career in building physics and sustainability.

Quentin Jackson
Quentin is an Environmental Modelling and Sustainable Design specialist and leads Aurecon’s Sustainability team in Queensland.

Dr Paul Bannister
Dr Paul Bannister is Director of Innovation and Sustainability at Energy Action. He is an internationally recognised authority on energy efficiency in commercial buildings and is the primary technical author of the NABERS Energy and Water ratings systems.

Paul Stoller
Managing Director of Atelier Ten’s Australia offices, Paul Stoller is recognised for environmental planning and design consulting work on large-scale campus, community and urban building projects.

General Information

The 2018  Building Performance Analysis Conference and SimBuild, co-organized by ASHRAE and IBPSA-USA, will be held September 26-28, 2018 at the Hilton Chicago, Chicago, IL. It is the third co-organized conference between ASHRAE and IBPSA-USA.

The goal of this conference is to present the new techniques and workflows that will help researchers and practitioners make better decisions during the simulation and modeling process of an entire building life cycle.

The conference program will consist of Keynote Speakers, Invited Speakers, a Call for Papers, a Call for Presenters and the fourth ASHRAE LowDown Showdown. Special panels may be offered by industry leaders and organizations.


Call for Papers

ASHRAE and IBPSA-USA have announced a call for papers for the 2018 Building Performance Analysis Conference and SimBuild, co-organized by ASHRAE and IBPSA-USA. It will be the third co-organized conference between the two organizations and will take place at the Hilton Chicago, September 26 – 28, 2018.

“Building performance modeling is transforming the industry to meet the net zero and Architecture 2030 design goals, improving operational efficiency and occupant comfort,” said Krishnan Gowri, conference chair. “Recent advancements in machine learning, data science and sensor technologies are opening up new avenues to advance the analysis and modeling techniques to meet the challenges faced by designers and modelers.  This conference seeks to connect the researchers and industry practitioners to facilitate the adoption of these new techniques and workflows to make better decisions through the application of simulation and modeling over the entire building life cycle.”

Modelers, architects, software developers and researchers will address the practices of building performance analysis, energy modeling and building performance simulation using existing simulation tools, software development and future simulation research and applications.

Abstracts (250 words or less) are due October 23, 2017. If accepted, papers are due February 2, 2018 and will undergo a double-blind review. The conference papers will be a maximum of eight pages in length.

To submit a conference paper abstract please click here: https://www.conftool.net/bpacs2018/


Venue & Dates

The conference will take place at the Hilton Chicago. The conference will be Wednesday – Friday, September 26-28. Pre-conference workshops will be held September 24-25.

For more information see the website here: https://www.ashrae.org/membership–conferences/conferences/ashrae-conferences/2018-ashrae-building-performance-analysis-conference-and-simbuild

In preparation for our AGM on 11 October, IBPSA Australasia wants to find out what you are interested in seeing from us over the next year. Your responses will help shape the type of events we organise for 2018.Thanks for taking the time to fill out this brief survey, it shouldn’t take more than five minutes of your time.

Please respond before NOON on Wednesday, 11 October.

Survey link here

 

The Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH) and The International Building Performance Simulation Association Australasia (IBPSA) are proudly hosting a joint Australasian Building Simulation Conference in Melbourne, Australia on November 15–16, 2017.

The conference will provide a unique forum for the exchange of ideas and information between simulation researchers, simulation developers, building designers, and government legislators. It will explore how simulation is helping to improve building performance and will be an excellent opportunity to keep up to date with the latest innovations in the field of simulation and the energy performance of buildings.

Who should attend?

The conference is for anyone working in or learning about the field of building performance simulation including:

  • Building designers using simulation
  • Architects
  • Design engineers and consultants
  • Simulation researchers
  • Simulation developers
  • Building physicists
  • Regulators specifying simulation as an assessment methodology
  • Building material and equipment manufacturers
  • Building owners and operators


Key dates

  • Final program released August 18
  • Finalised and fully reviewed paper completed by September 22
  • Building Simulation 2017 Conference – November 15–16, 2017.
When
15/11/2017 – 16/11/2017
Where
Melbourne Convention and Exhibition Centre
Convention Centre
1 Convention Place
South Wharf, VIC 3006 Australia

 

For tickets visit the AIRAH website.

 

5-7pm 11 October 2017
Energy Action, L10, 28 Margaret St, Sydney
By phone: 1800 896 323 participant pin 7105 1170

The AGM of IBPSA Australasia will be held 5-7pm on Wednesday 11 October 2017 at the L10 meeting room of Energy Action, 28 Margaret St Sydney and by phone conference as per the details above.  As all current Board members were elected last year for a term of 2 years, there will be no Board elections this year. The agenda for the meeting will be:

  • Review of activities undertaken in 2016-2017
    • Report from President
    • Report from Committee Chairs
  • Approval of audited accounts for 2016-2017
  • Establish activities for 2017-2018
  • General business

All IBPSA members are invited to attend and participate – please RSVP to ibpsa@ibpsa-australasia.org

Dr Paul Bannister
President