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OAA TEUI Calculator

Total Energy Use Intensity Calculator for Ontario based projects

Patrick Chopson avatar
Written by Patrick Chopson
Updated over a week ago

cove.tool and the Sustainable Built Environment Committee (SBEC) of the Ontario Association of Architects (OAA) has come together to build a TEUI Calculator, a web-based app for performance evaluation for Ontario-based projects.

What does it do?

This application can produce a one-time, downloadable, or otherwise exportable ‘report card’ in PDF format for building-related energy performance metrics: TEUI , TEDI, and GHGI. In real-time licensed members of the OAA can visualize the data in the form of different charts and graphs as shown below.

The reason for producing such a tool is to serve a need identified by architects to produce an energy-use intensity rating for constructed projects of any scale, but notably for part 9 buildings where an energy model is often not required or performed. This need was further highlighted on review of the most recent OAA awards, which for the first time mandated submission of an Energy Usage Intensity (EUI) rating. For many architects, this was something they were ever calculating for the first time.

About the OAA TEUI Project

The TEUI project aims to simplify the understanding of objective, measurable performance values of buildings by representing energy and greenhouse gas emissions in three simple and absolute terms, as a function of building area over the course of a year. The values are as relevant when applied to a 20 story office tower as it is to a single-family residence, as a measure of energy and carbon intensity is connected to a representative square meter of any building. As the 1. TEUI, 2. TEDI and 3. GHGI ratings have gained traction in engineering and architectural parlance, we have aimed to make this data visually obvious with simple input from a year’s worth of energy bills. We feel the first step must be to see and understand the benchmark data, and then to act. The SBEC of the Ontario Association of Architects has been promoting the Provincial and Federal adoption of mandatory Energy Ratings using these measures for all buildings. But what would such ratings look like?

  1. TEUI = TOTAL ENERGY USE INTENSITY
    The sum of all energy used by a building on site (i.e. Electricity, gas, district heat), minus all renewable energy generated on site, divided by the Floor Area. (NET)

    Units: kWh/m2*yr
    Typical Range: 300 (terrible) to 100 (good)

  2. TEDI = THERMAL ENERGY DEMAND INTENSITY
    The annual heating load per floor area of a building. This is the amount of heat needed to offset the heat loss through the building envelope and condition the ventilation air and typically includes domestic hot water heating.

    Units: kWh/m2*yr
    Typical Range: 150 (terrible) to 15 (excellent) Examples of TEDI ratings below

  • 3. GHGI = GREENHOUSE GAS INTENSITY
    The sum of all carbon emissions generated by a building on site, plus carbon emissions generated off site as a function of energy use by type (i.e. Electrical Generation, Gas, Wood, Oil), minus all carbon offsets generated on or offsite (i.e. Bullfrog ‘Green Natural Gas’). // refer to ISO 16745-2:2017 (NET) Note: Not All Regions Equal. QC = 98% GHG Neutral, ON =90% (58% Nuclear).

    Units: MT/yr ~ or MT/m2*yr
    Typical Range: 10 MT/yr (terrible) to 1 MT/yr (amazing)

Establishing and popularizing this method and approach is a first step in benchmarking existing buildings, and the next step is to target future building performance in these same terms, as a reflection of our National and Provincial commitments to taking action on Climate Change. The OAA could furthermore submit these standardized guidelines to municipalities that could in turn adopt these values and measurements as a standard practice at the issuance of Occupancy Permits and Post Occupancy Review and Reporting (12 months after Occupancy).

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