Zero Energy Design: Designing Residences for Maximum Energy Efficiency
Sustainability is not an added construct; it is a way of living. When it comes to enabling such living through architecture, the role of sustainable design that prioritizes energy-efficiency assumes immense significance.
Contrary to common assumptions, zero energy design does not take away from user comfort; in fact, it is about limiting energy consumption to a minimum while ensuring maximum thermal comfort, occupant productivity and wellbeing. Many factors, including architectural planning, form development and the choice of materials can go a long way in ensuring energy efficiency. Additionally, adopting active strategies such harnessing solar energy through photovoltaic (PV) panels, efficient HVAC systems, Energy Star-rated appliances, glazed windows and other measures can help conserve energy and reduce our dependence on automated heating and cooling. Moreover, planning for adaptability as per user requirements is fast becoming a key consideration in creating comfortable indoor environments. Offering occupants, the flexibility to control building features to suit themselves is something that we need to factor in, as we work towards designing for the future.
At ZED Lab, we follow a three-M philosophy to design homes for energy efficiency: Measure, Minimize and Mitigate. Through preliminary studies and analyses, we calculate the energy requirements for a project (building loads such as the heat load, electrical needs, etc.). We then design to minimize the residence’s environmental impact by keeping in mind observations and inferences from our studies that are backed by computational analyses. The first and foremost consideration for designing would be orientation. The second step is to understand the usage of interstitial spaces and work towards minimizing the heat load through the building envelope. The design, size and orientation of openings, which include window shading devices, and maintaining effective wall-to-window-ratios, is arrived at through solar radiation studies. We also study wall sections and the thermal properties of materials as well as u-values of glazing to determine the design of external walls. The forms and sizes of fenestration are designed to maximize daylighting within the interior spaces to as much as 100 per cent, bringing down the home’s electricity loads.
Between the building and its immediate environment, we work with local materials and landscape strategies to address the heat-island effect. The building’s heat loads can be significantly lowered by integrating heat sinks such as water bodies and incorporating native vegetation. Another critical factor to address is water consumption. An essential component of water management is rainwater harvesting. Recycling and reusing water for cleaning, and horticulture is a simple yet vital step towards conservation. Separation of organic and inorganic waste is also taken into account as part of this comprehensive design intervention.
Lastly, our principle of mitigation incorporates systems that harness renewable resources, such as installing PV panels on the roofs to fulfil hot water requirements, etc. These interventions work in tandem for maximum energy efficiency and overall cost savings.
Within our built environment, the concept of energy efficiency puts into focus how we can assimilate architectural wisdom from our vernacular and leverage modern technology to develop zero energy building. Fundamentally, it calls for designing in tune with nature, site, and climate.
Photography: Noughts and Crosses | Andre J. Fanthome