Accelerated deep energy retrofit plans for affordable public housing

The Nova Scotia Provincial Housing Agency has identified a major barrier to the sustainability of affordable housing. This challenge is mainly due to a lack of information about the current energy performance and potential impacts of energy retrofits on their building stock. Natural Resources Canada’s (NRCan) EnerGuide ratings offer some insight into the energy performance of existing homes. However, this data is not enough to create a business case for deep energy retrofits. This research project aims to rapidly evaluate energy efficiency and maintenance renovation impacts at portfolio-wide scale. It will explore use of computer-aided design and evaluation, also known as parametric modelling. This approach aims to quickly and accurately assess the potential for targeted energy improvements across numerous buildings.

Project scope and expected outcomes

Assessing and acting on energy efficiency

The Nova Scotia Provincial Housing Agency manages over 3,000 low-rise affordable housing rental units. However, there is a lack of energy advisor capacity and funding for in-depth energy assessments on each building in its large portfolio in the near-term. Without tools that examine complex and interconnected retrofit options, it can be easy to miss energy efficiency upgrade opportunities. This may lead to misidentification of the best approach to achieve project goals.  

This one-year research project aims to develop a repeatable method to quickly identify which buildings to target and which energy efficiency retrofits to recommend.

The first phase will conduct rapid assessments for about 200 homes using existing building data provided by:

• the building portfolio’s owner
• publicly available data
• NRCan housing archetype information to build energy models

Building features provided in the assessments include:

• age of construction
• number of stories
• floor area
• existing mechanical systems

Cost-optimized upgrade pathways will then be developed for each building using machine learning and parametric modeling to help evaluate energy efficiency upgrades across the portfolio at scale. The project aims to incorporate automated processes into the Volta SNAP platform. This platform is an energy advisor toolkit that can generate NRCan-compliant HOT2000 files. It can also perform deeper analysis and calculations beyond what the HOT2000 software can do.

The second phase gathers site-specific characteristics of the buildings to help refine retrofit plans, reducing the margin of error and identifying potential barriers. This stage gives insight into the challenges of upgrading individual buildings. It involves on-site data collection that would be done by support personnel instead of NRCan-registered energy advisors. The goal is to see if accurate, customized upgrade plans can be made on a large scale. This research team will aim to do this without tapping into limited energy advisor capacity.

Phase three investigates ways to improve the efficiency of energy advisors as they produce retrofit plans for housing providers. This project will pre-populate HOT2000 files and provide energy advisors with parametric modelling capabilities to support the development of upgrade plans. The combination of on-site EnerGuide assessments and data-driven upgrade optimization is expected to result in upgrade plans that offer improved value to building owners.

Outcomes to accelerate energy evaluations

The research project will create a program model that accelerates the energy evaluation process across the Nova Scotia Provincial Housing Agency’s properties. It’ll develop a methodology to support the fast, efficient and effective design of retrofits on a mass scale. Evaluating communities instead of individual homes will create inventories of upgrades common across building types. This can help develop regional planning and bulk purchasing strategies, focusing activities around procurement and driving the market for deep energy retrofits at scale across the province.

See more examples of projects funded through the National Housing Strategy Research and Planning Fund.