Architects as Energy Experts

Featured image above: Muskoka River House, Designed to the R2000 standard for Code Compliance (but not certified) for Altius Architecture/Trevor McIvor Architect by Andy Thomson

Over the years it has become clear to me that there are very different types of architects. Some are business and marketing experts, deftly winning new contracts and growing large firms. Others are design geniuses, creating sublime spaces and elegant structures, while still others – often the wallflowers – are technical experts, creating high-performance buildings with an arsenal of software tools. Even some of the best builders were trained as architects, but that does not necessarily make them great designers. Even the best designers can be out of touch with matters of technical execution or energy performance. My point is: It is rare to see a single individual possess all of these various skills. The best mix is often found in a team of designers, blending the skills of each individual’s strengths for resulting whole that is greater than the sum of its parts. In this post however we will be paying special attention to the wallflowers, because they hold the keys to any team’s ability to deliver not just excellent architecture, but excellent high performance architecture.


Performance Energy Modeling Professional: A Term sometimes found at the bottom of EEDS or Energy Efficiency Design Summary forms that were created by OHBA and OBOA as a convenience for review of SB10 and SB12 information. The term is not a regulated designation and as such no specific designation is required for OBC compliance in a Performance Path submission, except when the Performance Path is targeting EnerGuide or R2000 certification, at which point only a certified Energy Evaluator may be used. Hot2000 can be used by Architects for Code Compliance purposes only, but not for Certification. Architects, Professional Engineers, BCINs or other Energy Advisor/Evaluators can be deemed Performance Energy Modelling professionals when they have the requisite experience and expertise.

Energy Advisor: Typically refers to an individual offering modelling and physical building evaluations for Code Compliance and Certification, typically under the EnerGuide or R2000 standards, a nationally-developed NRC (NRCan) program administered by CHBA federally and OHBA in Ontario. Training is provided only to Evaluators and not energy modellers, exclusively by the OHBA subsidiary EnerQuality.

Energy Evaluator: See Energy Advisor above. An Evaluator typically undertakes digital (simulation) and physical (blower door depressurization tests) Certification compliance, where an ‘Advisor‘ is typically the same individual only providing Code Compliance consulting only.

Energy Modelling for Design Optimization: Any professional designer can use simulation tools to experiment with building massing, area to volume ratios, orientation and thermal envelope values to arrive at an optimal design before advancing to design development and permit submission stages

Energy Modelling for Code Compliance: Sometimes referred to as Performance Path modelling, when (in Ontario/OBC) a designer chooses to use a WWR (Window Wall Ratio) greater than 22%, or when levels above code minimums are desired.

Energy Modelling for Certification: The last and final step in demonstrating how a designed building will meet certification requirements of a given standard ie. Passive House or LEED, typically undertaken by a Certified Energy Modelling Professional or Evaluator.

When I was asked to be a technical adjudicator for the biennial OAA Awards, I had the opportunity to see all of this this firsthand. 2020 was the first year that the OAA required EUI (Energy Use Intensity in ekWh/m2*a) as a submission prerequisite, and while most of the larger firms had a refined and clear approach to the presentation of their energy, carbon and environmental data, most of the smaller firms (ie. Part 9 buildings) submitted reports created by non-architect Energy Evaluators – implying basically that few if any architects working on small buildings do performance path modelling in-house. If we have any hope of meeting our climate change abatement goals, this needs to change.

In 1997, as a former builder and R2000 program Delivery Agent I used to be exactly one of these Energy Evaluators, reviewing thousands of subdivision designs in analysis software (Hot2000), designing and even installing mechanical systems and HRVs (Heat Recovery Ventilators), and then performing system balancing/commissioning and door-fan tests (aka. ‘blower-door’ tests) to check whether the designed airtightness level (typically better than 1.5ACH@50Pa) had been met. The extent of our design advice to builders when working as an energy advisor was limited to simple tweaks to the envelope, from windows (triple or double), to insulation levels, to targeted airtightness levels. There was no impulse or latitude to suggest changes to orientation, or building form, or overhangs, etc. – even knowing that design optimization of this order would create substantial improvements on performance metrics. At that time I had trained at NRCan’s Ottawa facility under my mentors Architect Richard Kadulski and builder/advisor John Godden, but most Energy Advisors at the time were either builders or engineers, rarely architects.

To make matters worse, BEM platforms have been heavy on the complex mechanical modelling side, with less emphasis on the geometric and passive modelling features. This has had the inadvertent effect of mechanical engineers assuming the role of BEM experts for the purposes of both systems sizing and code compliance, leaving architects at the mercy of engineers to finish the job often with the tacit understanding that the general design of the architecture is not to be modified from this point on, missing the opportunity to explore passive design optimization with the significant economic and performance advantages this process entails. Just as architects have reluctantly embraced BIM from CAD, so now we need to take our BIM platforms to the next level with integrated BEM or Building Energy Modelling.

1995: Early energy modelling software like SUNCODE didn’t even have an interface to speak of, it was just a pile of algorithms that referenced material assembly lists, operating schedules and mechanical equipment specs. No wonder few architects engaged with these programs. ‘Energy Scheming’ changed that with a UI designed for the Macintosh, but until programs like EnergyPro and Hot2000 developed tree structure interfaces in MS Windows, learning these programs was cumbersome at best.

As my career progressed through the 90’s and 00’s, I was finding that very few of my colleagues had any grounding in energy modelling or building performance. Sure we all had taken mandatory material science, physics and even several courses on thermodynamics at university, so we understood the terms and the general idea of heatloss and thermal resistance. Many of us had LEED credentials to boot, but we seldom had any opportunity for training in BEM or even in formal design for environmental performance. Blame our education system or the low cost of energy in Canada, but energy performance just wasn’t a priority in the 80’s and 90’s.

That is in fact why I left my undergraduate program in 1994 at Ryerson University for an exchange program at the University of Stuttgart, where there were dozens of courses I could take at the Institute for Building Economics (mostly energy modelling) and Frei Otto’s Institute for Lightweight Structures, where I would learn about materials optimization and ephemeralization. There was nothing like that in Universities in Canada at that time, but I am glad to see this is changing. 30 years later, CALA is just now requiring it. And many Universities are teaching Passive House principles and PHPP (the evaluation spreadsheets from Passivhaus International). As you see below, the most significant impacts on the energy and carbon impacts of a design, with the least cost, are made in the early stages of design, as is noted in the AIA’s Architect’s guide to integrating energy modeling in the design process.

click image to enlarge

So design, and notably the passive components of a design, the things architects are responsible for like the walls and roofs and windows and basements and the materials they are made of, and how tightly they are put together, can have a much more dramatic effect on performance results than the active systems, the things engineers are responsible for, consisting of fans and ducts and resistors and compressors. In fact in the review of the OAA Awards for 2020, it could be seen that large building energy loads had been reduced by as much as 70% over reference models at the code minimum, and operational GHG emissions were reduced by over 90%, and with energy load reductions of this magnitude, 100% electrification of buildings becomes tenable, and these massive savings were largely the effect of design optimization of the passive elements of the design. With a 100% renewable grid, these buildings then truly become net-zero energy and zero operational carbon (embodied energy and carbon notwithstanding).

We can see that this is the future, but we are standing one one side of a canyon with our unsustainable architecture. We need to reach the other side to arrive at regenerative and climate neutral architecture, but what’s the best way to get across? The bridge we need to build in this metaphor is software, and software that is not only easy for architects to understand and use, but that can give immediate feedback on the impacts of design changes. But modelling for performance prediction and modelling for certification compliance are two different animals.

To this point, post-occupancy review of operating buildings often present a very different picture of energy performance from what was predicted by the models. In this light, the AIA has produced their Guide for Sustainable Projects, where on page 11 they capture the issue: “When considering certification systems or sustainable design elements, it may be necessary to distinguish between certification and building performance. A building that has achieved a specific certification will not necessarily realize enhanced performance, and therefore, may not meet an Owner’s performance expectations. Conversely, a building that meets the Owner’s performance expectations or incorporates sustainable design and construction elements may not qualify for a particular certification because it may not meet all certification requirements.” In fact, this is why modellers often refer to compliance with standards rather than actual prediction or prognostication. End-user behaviour can completely skewer actual loads from the tidy math of predicted loads, such as one example where a homeowner set up a welding shop in the garage and a hot tub in the backyard. Net-zero be damned, one needs a good soak after building a monster truck after all.

New and better tools thankfully are emerging and I have written a quick blurb on some of my current and past favourites below. How do these BEM platforms compare? All of the platforms listed below align with ASHRAE 140 , which is the most objective lens to evaluate each BEM platform through as a kind of benchmarking standard:

“Building Energy Modeling (BEM) is the basis for a number of building energy-efficiency activities including energy-efficiency standards. These activities could not take place without confidence in building energy modeling engines. ASHRAE Standard 140 is the framework for establishing this confidence in energy modeling engines and—collectively—in the energy modeling enterprise.”

ArchiCad, EcoDesigner: I have written extensively about EcoDesigner, the first and only truly integrated BIM/BEM modeller we know of, it runs hourly analysis directly inside of ArchiCad using AC’s native Zone tool, and is super fast. Features include graphical thermal bridge analysis and hourly solar mask calculations for every opening in the building. It can handle single houses just as easily as condo towers. This BEM takes some considerable ArchiCad knowledge to set up and run correctly, but the results are amazing (ie. the graphical monthly energy balance reporting) and allows customized report exports, detailed spreadsheet and gbXML export as well as partial PHPP export.

Ease of Use: Moderate Compliance: Tested to ASHRAE 140.
Cost: Free with Purchase of ArchiCad 24

Cove.Tools: We have not yet tried but we are very excited to. Supports BIM exports and has a complete 3D web-based interface with climate and relevant code data for all of Canada.

Ease of Use: TBD Compliance: Benchmarked to ASHRAE 140.
Cost: ~$300/mo (USD)

EnergyPro: Ideal for cooling climates, this small and medium building simulation software was developed in California and is one of the softwares certified for use for T24 compliance in the State of California. If you want to test thermal mass effects, rammed earth buildings and the effects of free cooling or night-time cooling, this is a great platform to use and compare results from Hot2000 with, since Hot2000 has no free cooling option and limited thermal mass consideration. The H2K interface is a tree structure that runs on MS Windows only.

Ease of Use: Easy
Cost: ~$1,200.00 USD

Hot2000: Developed by the Canadian taxpayer under NRC, Hot2000 is free to download and use but has watermarked/locked sections for checking EnerGuide and Hot2000 certification compliance. This has caused problems for reviewing simulations in the context of Design Optimization and Code Compliance when Architects wish to compare their designs against a known standard but do not intend to pursue the path to certifications. We are currently working with NRC to obtain a special release of Hot2000 for Architects for the sole purpose of Design Optimization and Code Compliance, where certification services will still reside with NRC-Certified Energy Evaluators. MS Windows only, tree structure interface. No BIM integration. Uses HVI listed HRV values and calculates effective R values and window U-values based on internal calculators and selectors.

Ease of use: Easy.
Cost: Free

PHPP: Basically a fancy, multi-tabbed spreadsheet used for design optimization and certification to the Passive House International Standard. There is a Sketchup plugin called DesignPH which is used by some of my colleagues but this is not a true BIM/BEM platform. Currently BIM2PH is a development project, and ArchiCad’s EcoDesigner exports partial data to PHPP version 9.6.

Ease of use: Onerous
Compliance: PHPP and ASHRAE 140
Cost: $276.88

So with a bit of education and a lot of dabbling, every architecture firm can empower a dedicated BIM to BEM expert on staff. But at what point can an architects claim to be ‘energy experts’? What qualifies anyone for that matter? While energy modelling on its own is an unregulated professional activity, the responsibility for a licensed architect or engineer to exercise professional judgement in the use of any design tool falls squarely within their respective scope of practice and is subject to the limits of their mandatory professional liability insurance. Nobody should be calling themselves an expert unless they actually are an expert – and that applies equally to engineers and architects. While there is no Act of legislation that precludes licensed Architects from undertaking Energy Performance Modelling for the purposes of Design Optimization or Code Compliance, a Certified Energy Evaluator may be required when a project targets a specific certification ie. Passive House, R2000, EnerGuide, LEED or others. This being said, no Architect would be advised to undertake Performance Energy Modelling for any purpose without sufficient training or experience, as is required by our mandatory professional liability insurance.

In conclusion, Architects can and should use BEM or energy simulation tools for Design Optimization. Furthermore they can and should also be encouraged to use BEM for demonstrating Code Compliance. Lastly, Architects should also be encouraged to seek out professional certifications or designations such as LEED, Passive House and even EnerGuide or R2000 Evaluator designations in order to offer Certification Services, if they wish to expand their scope of practice. The Ontario Building Code’s SB10 (for larger or Part 3 buildings) and SB12 (for smaller or Part 9 Buildings) provide a list of requirements for performance path modelling procedures and BEM softwares that is not meant to be exclusive, but provides a framework for appropriate BEM modelling tools and reference model methods that can be used to demonstrate compliance. Architects, once familiar with BEM modelling can then complete the EEDS forms (sample below from the City of Toronto) with their own professional credentials such as their OAA license number.


The ways in which Sustainable Architecture has changed, and stayed the same, since 1977.


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