As the technical requirements of building envelopes have evolved, fire performance has become a key criterion in the design of ventilated facades. Given this situation, analyses no longer focus solely on the individual reaction of materials, but also on the joint response of the entire building envelope under possible scenarios of external fire propagation.
This article is part of our new Opinion section, a format for argument-driven essays on critical questions shaping our field.
The modern sustainability project is built on the promise that evolving technologies can reconcile urban and economic growth with ecological responsibility. By the metrics developed by the built environment professions and the policies adopted by governments, progress is tangible and accelerating: buildings consume less energy per square foot than they did a generation ago, vehicles emit fewer pollutants per mile, and urban infrastructure is more integrated and measurably cleaner in many cities. And yet total resource consumption continues to rise. Sustainability, as currently practiced across the built environment professions, has become a strategy for optimizing consumption rather than reducing it. Until the profession is willing to question the scale and structure of demand rather than the efficiency with which that demand is met, its most celebrated achievements will continue to fall short of the problem they claim to address.
The global offsite construction market—encompassing modular, precast concrete, and hybrid prefabricated systems—was valued at USD 172 billion in 2024 and is projected to reach USD 225.7 billion by 2030 (CAGR 4.9–8%). In the UAE, government targets call for 25–30% offsite content in public projects by 2030; the UK currently leads globally, with 15–20% of housing using offsite solutions. Offsite manufacturing is increasingly promoted as the sustainable future of construction, with benefits including reduced waste, accelerated delivery, and improved quality control. Sustainability is not defined by how quickly a building is assembled. It is defined by how long it performs.
In temperate and cold climates, architecture typically begins with a defensive gesture. The building envelope is a sealed boundary designed to resist the exterior environment through insulation, vapor barriers, and mechanical control. In cold countries like Canada, where winter temperatures can plunge well below freezing, airtightness is not a luxury. In this context, buildings must resist the exterior environment entirely to maintain interior comfort. However, in Central America, a region spanning from Belize to Panama, architectural logic shifts from exclusion to negotiation. In this region, the envelope is not a wall of defense but a specialized filter.
In the coastal and jungle regions of Costa Rica, high humidity and intense solar radiation dictate an architectural strategy centered on permeability rather than enclosure. Unlike the airtight envelopes required in cold climates to retain heat, Costa Rican architecture uses the building envelope as a climatic filter to maximize air exchange. The primary mechanism for managing these thermal gradients seems to be the oversized roof overhang. By extending the roof plane significantly beyond the floor plate, architects create a permanent buffer of deep shade that reduces solar gain and lowers the ambient temperature before air enters the structure. This strategy, combined with permeable or non-existent walls, allows for constant airflow. This is a critical technical requirement for humidity control and the prevention of material degradation through mold and rot.
What if industrial leftovers weren't waste, but the start of architectural design? At Rieder's headquarters in Maishofen, Austria, over 1,300 cubic meters of timber, 180 ceiling elements, and hundreds of upcycled glassfiber-reinforced concrete fragments come together in a building shaped as much by reuse as by planning. The new production hall, designed by Kessler² Architecture, treats material leftovers as a design resource. Developed as part of a long-term investment in sustainable manufacturing, the timber-concrete hybrid building introduces a facade technique that inverts conventional architectural workflows: instead of designing first and producing components afterward, the building envelope is generated from the material remnants already available on site establishing a new language for industrial architecture.
Architecture has always played a key role in providing shelter and protection for human beings. In prehistoric times, we sought refuge in caves, taking advantage of rock structures for protection against the natural elements and predators. Over time, shelters began to be made from materials found in nature, such as branches, leaves, and animal skins, evolving into more permanent and complex homes, with walls made of stone, bricks or wood, roofs to protect against rain and sun, and doors to control access. As we developed more advanced building skills, we used materials such as wood, stone, and clay and architecture evolved significantly, with the construction of temples, palaces, and fortifications that provided not only shelter but also symbolized power, status, and cultural identity. Even so, our buildings can continue to be seen as shells that protect us from the outside world.
From the massive stones of Greek temples to glazed skyscrapers, we work with a range of possibilities and thicknesses to separate what we consider internal and external. This article seeks to explore this diversity of thicknesses in architecture, from simple materials to complex construction techniques, highlighting how this variation not only provides protection but also influences our perception and interaction with the built environment.
There is growing awareness around sustainability—and the environmental cost of prematurely demolishing safe, structurally sound buildings only to replace them with new construction. In the broader race to reduce carbon emissions, corporations and institutions are placing greater emphasis on ESG performance (environmental impact, social responsibility, and governance). Many now require carbon accounting, set "carbon-neutral" targets, or purchase carbon credits to offset footprints.
This shift, together with a wave of exemplary adaptive-reuse projects worldwide—Herzog & de Meuron's Tai Kwun in Hong Kong, Powerhouse Arts in Brooklyn, David Chipperfield's The Ned Doha, and Xu Tiantian's transformations of factories, quarries, and rammed-earth fortresses in China—has accelerated serious reconsideration of reuse as a primary development strategy. Yet despite its many benefits, adaptive reuse is still not as prevalent as it could be. Why and what might be the main obstacles and tensions?
The main role of architecture is to create structures that protect us from the environment and create spaces that are safe and comfortable for all types of needs and activities. By providing shelter, architecture also shapes the way people interact with their surroundings. Building technologies of the past rarely managed, however, to create a complete separation between us and the outside world.
While impermeability was a desired outcome, the porous building materials available always allowed some water, wind, or outside particles to leak into the interior spaces. In contrast, modern technologies now allow for almost completely impermeable building envelopes, allowing for complete separation between indoors and outdoors, thus relying on engineered systems to regulate temperature, airflow, or humidity. This article explores the differences between these two contrasting approaches, exploring how building facades are equipped to regulate indoor comfort and its environmental impact.
Over-providing traditionally implies offering more than is necessary, often carrying a negative connotation due to the potential for excess and waste. However, could there be scenarios within the built environment where over-providing proves advantageous? The question critically examines how overprovisioning might enhance a building's flexibility and adaptability to diverse and evolving conditions.
The underlying assumption of accurately providing what is needed for a building is that stakeholders—including owners, architects, and designers—can accurately predict and cater to a structure's current and future needs. This assumption, however, is challenging to realize, as societal, economic, and cultural shifts frequently occur in unpredictable ways. In this context, over-providing emerges as a counterintuitive yet potentially beneficial strategy. As buildings and structures inevitably transform, those designed with inherent adaptability reduce the need for costly renovations or complete rebuilds.
In the evolving landscape of architecture and urban design, bioclimatic and biogenic envelopes present a compelling vision for future cities. Dr. Arta Yazdanseta, a Doctor of Design focused on energy and environments, dives into the intersection of design, building performance, and plant biophysical ecology. With a focus on bioclimatic and biogenic envelopes, Dr. Yazdanseta examines how these typologies can enhance socio-natural systems by leveraging their self-organizing potential. Dr. Yazdanseta’s academic journey includes earning a Doctor of Design and a Master of Design in Energy and Environments from the Harvard Graduate School of Design.
Her contributions as a researcher at the Harvard Center for Green Buildings and Cities include developing environmental design strategies and performance analyses for the HouseZero carbon retrofit project. In this interview, Dr. Yazdanseta explores the concept of bioclimatic envelopes and their interaction with passive architectural design principles. With a potential to revolutionize urban environments, the interview reveals insights into her research, the benefits of plant-based materials, and the future of sustainable architecture, emphasizing the critical connection between human and environmental health.
Formally, transparency usually takes the shape of a window, a door, a curtain wall, or a skylight. These are commonly created through rectangular punched openings or in the form of glass curtain wall systems or translucent screens. The following projects play with traditional notions of transparency and window-making in playful and unconventional ways. They create visually striking facades and dynamic relationships between their exterior and interior. They filter light and frame views through their glazing and opening articulation to craft memorable architectural experiences.
Positioned between the streetscape of a neighborhood and the privacy of the interior of a house lies the porch. Taking on the role of an entrance, a window to ponder out of, a gathering spot, and a stage, the porch has come to represent community and identity for many neighborhoods in the United States. Made of various stylistic elements of different sizes and shapes, these tie together neighborhoods by creating an interstitial space between the home and the street, weaving together the family life inside the house and the public life outside it, and creating a space between the private and public for both serendipitous encounters and for pausing. The porch has often been displayed in film and literature as the stage of profound and life-changing conversations, representing a comfortable threshold between the domestic and public realm in which to linger.
Glass brick facades have emerged as a captivating architectural trend, blending the enduring elegance of glass with the robust strength of bricks. Glass bricks can as well be more thermally resistant than conventional glazing.
These facades add a pixelated effect that plays with light and shadow, perfectly transmitting light, while maintaining privacy. The way glass bricks facades soften and blend the views of the outside can increase calmness and focus. From sleek commercial buildings to avant-garde residential projects, glass brick facades continue to push the boundaries of architectural innovation, captivating both designers and observers alike.
As a highly transparent material that stands up to all but the most extreme of weather conditions, is easily formed into any size or shape, and, once formed, will last for thousands of years, glass is still one of the most innovative and crucial materials used in architecture. Although contemporary building practices allow us to form huge, glittering skyscrapers of glass that rise hundreds of meters into the air, the ancient material’s original purpose – to welcome light into weathertight and secure interiors – remains its most important more than a thousand years on.
As important as glass is to almost every typology of architecture in the form of windows, when it comes to the roof of a building, the use of glass is not so simple. We’ve understood the power and danger of combining light and glass ever since we saw a magnifying glass used to concentrate the heat of sunlight into incredibly high temperatures in children’s cartoons. Under a glass roof, the solar gain can make for uncomfortable internal environments without the correct protective precautions.
Rising demands for energy efficiency, technical functionality, and interior comfort in buildings necessitate the development of more efficient building envelope constructions. The building envelope serves as a mediator between a building's exterior and interior. In today's architectural landscape, it performs a multitude of functions to enhance the building's performance. These functions include building control systems, energy supply (such as gas and electricity), and heating, ventilation, and air conditioning (HVAC), among others. These elements primarily determine the functionality, efficiency, and safety of building spaces. Given that the nature of building envelopes heavily depends on these services, how can they serve as primary frameworks for building design development?
When we talk about the building envelope, we often make the analogy of a skin that protects and wraps the structure, creating a transition in the physical environment. This concept is interesting as it identifies that, similar to its function in humans, the skin plays a role in protecting and regulating the interior setting, besides contributing to the aesthetics of the building. In this way, both the human skin and the building envelope act as elements that respond to the stimuli of the surroundings and the life that develops within them. More than just protective barriers, they are experienced as means of active interaction with the context.
While envelopes evolve within diverse contexts, materials, and systems, minimalist windows distinguish themselves through their aesthetic qualities by being transparent and fluid skins. These windows excel with their functionality and visual lightness, standing out in the architectural landscape. In addition, they are noteworthy thanks to their versatility across different systems that connect life within the interior and exterior. Considering Swiss and Pritzker Prize-winning architect Peter Zumthor's statement that "architecture is exposed to life,” windows play a vital role in expressing that connection, becoming a significant part of the building's identity and essence.
Building envelopes create a physical boundary or shell integrated to the outer skin of a structure, separating indoor and outdoor environments. By assembling architectural components such as walls, roofs, windows and doors, the building is enclosed to provide protection and insulation, playing a determining role in the energy efficiency, comfort, structure, and durability of the project. Through multiple styles and shapes, they are key to giving character to a building, its visual appearance and integration with the surrounding environment.
Maintaining the fundamental functions of an envelope while playing with aesthetic possibilities, Euramax’s tailor-made metal cladding solutions create unconventional, colorful envelopes for designing with innovative geometries, patterns, and configurations.
