In 2023, Warmset Australia’s founder and managing director, Giovanna Toldi, set out to deepen her understanding of energy-efficient building design. To do so, she attended a few courses at TU Delft University of Technology, a global leader in sustainable architecture and engineering.
Recognising that most homeowners and builders interested in designing energy-efficient buildings aren’t engineers, we’ve put together this practical guide — highlighting the three key steps to a low-energy, comfortable home.
Designing an energy-efficient building is no longer a niche pursuit—it’s a critical component of modern architecture that aligns with global goals around sustainability, cost-efficiency, and comfort. Whether you’re designing a home, office, or public space, applying a structured strategy can drastically reduce a building’s energy consumption and environmental impact.
One of the most effective frameworks for this is the Three-Step Strategy. This approach, inspired by the flow of energy within a building (often referred to as the “energy chain”), provides a clear hierarchy for decision-making in sustainable design. Here’s how it works:
Three-Step Strategy for Energy-Efficient Building Design at a Glance
Three-Step Strategy for Energy-Efficient Building Design at a Glance
- Step 1: Reduce: Minimise the building’s energy demand through orientation, insulation, solar shading and passive design.
- Step 2: Renew: Meet remaining demand with solar, wind, geothermal or other renewable energy sources.
- Step 3: Optimise: If fossil fuels are still needed, use them with maximum efficiency as a last resort only.
Step 1: Reduce the Building’s Energy Demand
The most sustainable energy is the energy you don’t use. That’s why the first step in designing an energy-efficient building is to reduce energy demand from the outset.
Energy needs in buildings typically arise from heating, cooling, lighting, hot water, ventilation, and the use of appliances. These needs can be significantly reduced through smart design choices, such as:
- Optimizing building orientation for natural light and passive solar gain
- Improving insulation to reduce heat loss in winter and heat gain in summer
- Designing for compactness, minimizing unnecessary surface area
- Using solar shading or blinds to prevent overheating from sun exposure
Additionally, you can reuse energy already present in the building. For example, heat recovery systems in ventilation and hot water can capture waste heat and repurpose it. Passive systems like Trombe walls—which absorb solar energy during the day and release it at night—are also effective in reducing new energy input.
How does Warmset play a role in this? Well, one of our key feature is that we are able to custom-build a system specifically to the unique requirements of your project. For example, a well-insulated home can be heated with just 45W/sqm, so why install a standard 150W/sqm mat?
Step 2: Power Your Building With Renewable Energy
Once energy needs have been minimized, the next priority is to meet remaining demand using renewable or “infinite” energy sources. These resources do not deplete over time and are much cleaner in terms of emissions.
Common examples include:
- Solar energy (photovoltaic panels or solar thermal collectors)
- Wind power
- Geothermal energy
- Hydrogen (when produced sustainably, such as via wind-powered electrolysis)
In some cases, reusing waste energy from nearby buildings or industries can also be considered a sustainable source. For instance, excess heat from data centres can be repurposed to warm residential buildings.
One important consideration: many renewable sources are intermittent. The sun doesn’t always shine, and the wind doesn’t always blow—so energy storage becomes crucial to ensure consistent supply.
How does Warmset play a role in this? Warmset can be connected to your solar energy source, drastically reducing your dependence on electricity generated by fossil fuels.
Step 3: Use Fossil Fuels Only as a Last Resort – Efficiently
If, after following steps one and two, there is still an unmet energy demand, fossil fuels may still be necessary—but they should be used sparingly and efficiently.
Efficiency in this context means using fossil fuels only where they provide maximum benefit. For instance:
- Instead of using a gas boiler for daily heating, use it only as backup in extreme conditions, supplementing a heat pump during very cold periods.
- Consider combined heat and power (CHP) units, which generate both electricity and heat from a single fuel source—making far better use of the energy input.
The long-term goal is to eliminate fossil fuel dependence altogether, but until then, they should be treated as a last resort.
How does Warmset play a role in this? Warmset is a very efficient electrical system that radiates powerful and long-lasting FIR heating, reducing your need to keep your heating on for long.
Final Thoughts
The Three-Step Strategy offers a practical, phased approach to sustainable building design:
- Reduce the need for energy through design and efficiency.
- Use renewable resources to meet remaining demand.
- Use fossil fuels only if absolutely necessary—and in the most efficient way possible.
By following this sequence, architects, builders, and homeowners can drastically reduce both operating costs and environmental impacts, while creating more comfortable, future-ready buildings.
