Accelerated deep energy retrofit plans for affordable public housing

Learn how understanding the energy performance and impacts of energy retrofits on building stock can improve the sustainability of affordable public housing. This research shows that computer-aided design and evaluation, known as parametric modelling, can quickly and accurately assess the potential for targeted energy efficiency and maintenance and renovation improvements across numerous buildings.

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Project scope and outcomes

Finding deep energy retrofit opportunities

This research was led by Clean Nova Scotia Foundation. The foundation explored the use of parametric modelling to create a business case for deep energy retrofits.

The Nova Scotia Provincial Housing Agency manages over 3,000 low-rise affordable housing rental units. Performing traditional energy audits for such a large portfolio was expensive and took a lot of time. Without an efficient approach to analyze interconnected retrofit options, opportunities to enhance energy efficiency and sustainability risked being missed.

A new solution

This research project developed a method using readily available building data to quickly identify high-priority buildings and recommend targeted energy efficiency retrofits. This provides a cost-efficient alternative to conventional energy audits.

Promising results

The research determined it’s possible to build energy models even with limited building information. These models can be used to plan mass-scale retrofits or pre-construction upgrades for new buildings.

An algorithm can determine upgrade pathways for hundreds of buildings at once. The tool evaluates EnerGuide-rated annual energy savings and greenhouse gas reductions. Automation can rapidly produce upgrade plans for individual buildings that collectively aim for a common energy and greenhouse gas reduction goal across a portfolio.

When assessing a portfolio of buildings, there is a key point where rooftop solar photovoltaic (PV) becomes more cost-effective than the next best upgrade option until the roof area becomes overcrowded with solar panels. This key point can help planners decide when to include solar photovoltaic in their upgrade plans based on specific goals.

Value of the new tool

• This tool simplifies energy and greenhouse gas upgrade planning. It evaluates many upgrade options instead of relying on the energy advisor to determine a single upgrade pathway.
• The tool works for upgrade planning for single buildings as well as entire communities and for retrofits or new construction.

It may be especially useful for municipal, provincial and federal governments, landlords and others planning and implementing large-scale building upgrade programs.

Future improvements

The research team hopes this project will lead to a toolkit for energy advisors and estimators. The goal is to improve the quality of their recommendations while reducing administrative work. Future improvements include:

• Expanding the building data intake and analysis to include other goals, such as reducing fuel consumption and addressing neighbourhood energy poverty.
• Adding information on upgrade measures, such as regionalized pricing, cost of borrowing and the expected service life of upgrades.
• Collecting additional data on roof geometry, orientation of roof surfaces, localized shading effects and the regional costs of installing solar panels.

Download the final report (PDF)