Low-Tech, High-Performance
Passive Strategies for Reducing Operational Carbon
According to Architecture 2030, drawing on data from the International Energy Agency (IEA) and Statista, approximately 42% of annual global carbon emissions stem from the built environment. Nearly two-thirds of this figure is attributed to ongoing building operations like interior heating, cooling, lighting and ventilation. As climate concerns escalate and energy costs rise, architects and developers increasingly look toward passive design strategies to reduce a building’s carbon footprint, without significantly inflating construction costs.
Contrary to common assumptions, integrating passive design strategies does not necessarily increase building costs. Instead, it often redistributes them by minimizing reliance on costly mechanical systems and lowering long-term operational expenses. For example, orienting a building to maximize natural daylight and ventilation can reduce the need for artificial lighting and air conditioning. Similarly, incorporating shading devices or thermal mass elements can help regulate indoor temperatures without the use of electricity. These solutions are inherently site-specific and must consider climate, orientation, wind patterns and solar exposure to be most effective
KTGY’s Research and Development Studio explores how passive design strategies can be tailored to diverse site conditions, particularly in hot, dry climates where cooling loads are high. KTGY’s R+D design concept elements, proposes incorporating traditional Middle Eastern passive cooling methods into modern multifamily housing. The Elements design introduces ventilation stacks into a podium-style multifamily building. These stacks operate similarly to wind catchers found in historic desert architecture. Warm air is pulled down through chimneys and passed beneath the building, where the ground acts as athermal reservoir, cooling the air before it enters living spaces. At the same time, exhaust stacks on the corridor sides of the units draw warm air out, creating a pressure differential that drives passive air circulation, reducing the need for air conditioning during much of the year. While widely used in regions such as Iran and the Arabian Peninsula, this strategy remains underutilized in similarly arid areas of the American Southwest. This is a missed opportunity given its effectiveness and low energy profile.
Throughout history, indigenous architecture has relied on passive design principles long before modern mechanical systems became the norm. Techniques such as thermal mass, solar orientation, cross-ventilation and deep overhangs have helped people maintain comfort in a wide range of climates. These time-tested methods are being newly considered in contemporary design, especially as the construction industry faces increasing pressure to reduce operational carbon.
KTGY’s Enclave design concept builds on these traditional strategies while incorporating modern construction techniques such as 3D printing. Targeted for hot, dry environments, enclave challenges the limitations of gantry-style 3D printing, which has traditionally been used for tiny homes, by proposing a flexible, multi-structure layout suitable for larger or multigenerational households. The Enclave design features two separate yet connected structures: one for sleeping and another for living and cooking. The spaces are linked by an open-air screened porch that serves as a shaded, ventilated extension of the interior. Deep overhangs and cross-ventilation help keep the porch, as well as the adjacent interior spaces, cool during the day. A large ceiling fan-assists-air movement, reducing reliance on more energy-intensive mechanical systems. The thickness of the 3D-printed walls also serves as thermal mass, absorbing heat during the day and slowly releasing it at night-to-moderate indoor temperature swings.
According to Passive House International, design strategies alone can reduce operational carbon by up to 50%. In residential projects, this can result in lower utility bills and a reduced need for expensive HVAC systems, making housing more affordable in the long-term. Reduced reliance on fossil fuels also aligns with growing regulatory and market pressures to decarbonize the building sector. Governments and municipalities increasingly require aggressive energy performance standards while tenants and homeowners demand more sustainably comfortable living environments, putting passive cooling at the intersection of regulatory and consumer demand. By prioritizing passive design at the outset, developers can avoid the costs of retrofitting inefficient buildings later. Operational savings over time can significantly offset any marginal upfront investment in passive strategies.
As demonstrated by KTGY’s Elements and Enclave design concepts, passive strategies are not relics of the past, they are essential tools for the future. When applied with sensitivity to climate and site, these techniques can deliver resilient, comfortable and low-carbon homes without compromising affordability or livability. In doing so, they offer a roadmap for transforming the built environment from a source of carbon output to a solution for climate resilience.
Written by Marissa Kasdan. Marisa is the director of research and development at KTGY. She may be reached at mkasdan@ktgy.com.
This article appears in our September / October Issue of Green Home Builder.