The Importance of Retrofits Meeting the EnerPHit Standard in Australia
As we grapple with climate change and escalating energy costs, retrofitting our existing buildings to meet higher performance standards has emerged as a key strategy. According to the Australian Bureau of Statistics (ABS), there were approximately 10.8 million dwellings in Australia as of 2021, which means that there is a ton of work to do to bring these homes up to the current energy efficiency standards.
Among the various standards available, the EnerPHit standard, a rigorous retrofit standard developed by the Passive House Institute, stands out as a benchmark for achieving substantial energy savings and comfort improvements.
The average Australian home built before 2003 averages just 1.8 stars, with 70% of homes falling into the category. This shows the desperate need for so many houses to be bought up to current energy standards (this data was based on comparing homes to the 6-star platform with seven stars now the minimum standard).
What is EnerPHit?
EnerPHit is the retrofit version of the Passive House standard, tailored specifically for existing buildings. It emphasises achieving high energy efficiency, enhanced comfort, and reduced energy consumption through a comprehensive approach to building upgrades. Key features of EnerPHit include improved insulation, airtightness, high-performance windows, and a ventilation system with heat recovery.
EnerPHit is a retrofit standard developed by the Passive House Institute specifically for upgrading existing buildings. It is designed to apply the principles of Passive House to older buildings that may not be feasible to meet the full Passive House standards due to structural constraints or other limitations. The main goals of EnerPHit are:
Energy Efficiency Improvements: Improving the energy performance of existing buildings as much as possible while taking into account the constraints of retrofitting.
Comfort and Health: Enhancing indoor comfort and air quality through better insulation, airtightness, and ventilation.
Cost-Effectiveness: Providing a more flexible and cost-effective path for retrofitting older buildings compared to achieving full Passive House standards.
Sustainability: Reducing the overall energy consumption and environmental impact of existing buildings.
EnerPHit does not require buildings to meet the exact same energy performance metrics as new Passive House constructions but sets achievable targets that significantly improve the energy efficiency of retrofitted buildings. For instance, EnerPHit may allow for slightly higher heating and cooling energy consumption compared to new Passive Houses, recognising the practical limitations of retrofitting existing structures.
Why Retrofit?
Australia's existing building stock is diverse and often outdated, with many buildings lacking modern energy efficiency features. According to the Australian Building Codes Board (ABCB), over 70% of Australian homes were built before 2000, and many of these do not meet contemporary energy efficiency standards.
We are currently undertaking our first passive house retrofit where we wanted to prove that we could take a 30-year-old volume/spec home that was super uncomfortable and make it reach the highest testing standards of construction in the world - a certified passive house that is comfortable, healthy and energy efficient but also looks awesome!
There have been a number of studies and research that can relate directly to the comfort and health in Melbournes homes.
The CSIRO research discusses various factors affecting residential building performance, including insulation, thermal comfort, and energy efficiency. It provides insights into how these factors impact comfort levels in Australian homes. The WHO also ranks Australian homes as some of the coldest in the world! It is also thought that at least 25% of Australian homes are dealing with mould issues!
The Benefits of EnerPHit Retrofits
Energy Savings and Cost Reduction
Buildings that meet the EnerPHit standard can achieve up to 80% reduction in heating and cooling energy use compared to standard retrofits. For instance, a typical home retrofit under EnerPHit can significantly reduce heating load (our retrofit rifle project is going from 250kwh/m2 to around 26kwh/m2). In monetary terms, this translates to significant savings on energy bills (over $7k).
Enhanced Comfort
One of the key advantages of EnerPHit is the improvement in indoor comfort. Enhanced insulation and airtightness minimise temperature fluctuations and drafts, creating a stable and comfortable indoor environment. The Australian Building Codes Board (ABCB) reports that energy-efficient retrofits can lead to a 20-30% improvement in indoor comfort levels. If we look at areas like Yarraville, which has some of the worst air quality in Australia, indoor air quality becomes a point for discussion since we spend 90% of or time inside.
Improved Insulation:
EnerPHit retrofits involve enhancing the insulation of a building. By increasing the thickness and quality of insulation in walls, roofs, and floors, the interior surface temperatures are raised. This reduces the likelihood of cold spots where condensation could form, which is a common precursor to mould growth. Insulation is cheap but it's important to make sure it's installed correctly!
Enhanced Air Tightness:
The EnerPHit standard emphasises creating a highly airtight building envelope. This reduces the amount of uncontrolled air leakage, which helps to keep the building's internal conditions more stable and prevents moist outdoor air from infiltrating and condensing inside the building. The average Australian home sits around 15ACH; however, we were able to get this once 30ACH building down to .41ACH. This means we can take back control of the building and optimise comfort in the home (no one likes draughty buildings)
Reduced Carbon Footprint
By cutting down on energy consumption, EnerPHit retrofits significantly lower greenhouse gas emissions. According to the International Passive House Association, retrofitting to the EnerPHit standard can reduce a building's carbon footprint by up to 70%. In Australia, where the building sector contributes approximately 20% of national greenhouse gas emissions, this reduction is a substantial step toward meeting the country's climate goals.
Health and Well-being
Improved indoor air quality and thermal comfort resulting from EnerPHit retrofits can have significant health benefits. Reduced drafts and better ventilation lower the risk of respiratory issues and other health problems. The Australian Institute of Architects highlights that well-designed energy-efficient retrofits contribute to a healthier living environment, which is increasingly important as awareness of the health impacts of building performance grows. A crucial part of the EnerPHit approach is the installation of a high-performance mechanical ventilation system with heat recovery. This system ensures a continuous supply of fresh air while recovering heat from the outgoing stale air. By maintaining good air quality and controlling humidity levels, the ventilation system reduces the conditions under which mould can thrive.
Why Passive House in Melbourne is the answer
Melbourne's unique climate and building characteristics present both challenges and opportunities for retrofitting. Many Melbourne homes are designed with passive heating and cooling strategies, making them ideal candidates for EnerPHit retrofits. The Australian Government's 2022 report on "Energy Efficiency in Residential Buildings" underscores the potential for energy savings through retrofitting, noting that up to 40% of residential buildings could benefit from substantial improvements (Australian Government, 2022).
In Melbourne, where temperature fluctuations can be significant between hot summers and cold winters, enhancing energy efficiency is crucial. A 2023 study by the Australian Energy Market Operator (AEMO) found that improving energy efficiency in Melbourne homes could help manage these temperature extremes and reduce the strain on energy consumption and grid reliability (AEMO, 2023). By addressing these challenges through high-performance retrofits, Melbourne homeowners can achieve greater comfort and energy savings year-round..
But whilst we love data and reference points, let's break it down to this. Who wants an uncomfortable house (no one). So lets start building healthy passive house projects that are durable.
Meeting the EnerPHit standard in retrofitting Melbourne buildings is not just a trend but a necessity for achieving long-term sustainability, energy efficiency, and comfort. With significant reductions in energy use, cost savings, and health benefits, EnerPHit retrofits present a compelling case for homeowners and have a huge potential for developers and policymakers to make large mass changes to our industry..
We personally feel that a passive house is the answer to our building problems in Melbourne, and with so much existing housing stock, we would be silly to ignore the EnerPHit standard.