The facade of a building often serves as a reflection of both the urban fabric it is set in, as well as what lies behind it. Beyond aesthetics, facades hold important functional, cultural, and sustainable significance, especially in relation to the interior design. Although natural light, views, and spatial organization are influenced by the facade, architects have been prioritizing the relationship between the building's envelope and the quality of the interior, keeping in mind current cultural, economical, and environmental changes influencing the way people design their living space. So responding to these ever-changing needs and habits, along with the focus on overall wellbeing, architects offset the facade and ceiling - and in some particular cases, floors - to create interiors within interiors; secondary envelopes that protect the interior space from the outside environment.
Along with separating the interior and exterior, a building’s envelope is responsible for several aspects of its interior conditions and construction, such as ventilation, structural stability, climate regulation, insulation, prevention of moisture and humidity infiltration, and energy management. This is why a lot of consideration is done regarding the envelope’s material, placement, and dimensions. But in areas with extreme climatic conditions, relying on just the building facade to sustain the factors mentioned above is not enough, so a secondary wall, often a trombe wall, is added as a passive cooling and/or heating building system. But despite the fact that trombe walls are seen as a relatively-new passive construction system, the concept of transitional or buffer zones between exterior and interior to help mitigate direct sunlight and reduce heat gain inside the buildings has been adopted since centuries ago.
One of the most prominent structural innovations of Classical Architecture is the colonnade system, which features a long sequence of columns joined by an entablature at the top, allocated at the peripheries of a public building. In historic religious structures and palaces, courtyards were surrounded by shaded arcades and porticos. Projects in the Mediterranean region were built with thick walls but featured covered exterior walkways and courtyards that served as buffer zones to control the thermal properties of the interior. Traditional Japanese townhouses called Machiya feature narrow exterior corridors that separate the public street and main living space.
In this interior focus we will look at the ecological, physiological, and aesthetic purposes behind constructing secondary walls, along with 13 examples of how architects employed these buildings systems in contemporary projects.
Ecological Purposes
Environmentally-aware design solutions are some of the main reasons why architects choose to have double envelope buildings. In some projects, particularly those built in critical climatic conditions, a trombe wall is implemented as a passive solar building design strategy, absorbing the direct sunlight and transforming it into thermal energy that is properly distributed throughout the interior. The material, color, and placement of the trombe wall with respect to the building’s envelope is all dependent on the interior thermal quality intended by the architect. In terms of how trombe walls work, the solar heat passes through the first layer, which is a glass wall placed a few centimeters away from the masonry wall. The heat is then absorbed by the masonry wall and then slowly released into the interior space. This process allows for a longer wavelength solar radiation, reducing the need for mechanical heating systems. To maximize solar gain, the glass wall is often built facing the south and southwest, allowing it to collect more sun during the day.
Zamora Offices / Alberto Campo Baeza
Infiltrated Patio / PLUG Architecture
Libergier Sports Centre / philippe gibert architecte
Cornege-Preston House / Bonnifait + Associates
Promoting Physical Comfort
As cities become over congested with people and traffic, and buildings are constructed with reflective material, increased ambient noise levels have become a key factor behind why architects opt for secondary walls and volumes within an interior space. In projects that prioritize silence, such as offices and medical facilities, and can not alter or manipulate with the building’s facade, a secondary layer is implemented with the sole purpose of serving as an additional sound filter. Therefore, the material this wall (or in some cases, partition) is constructed with is often one that is sound absorbent.
Along with sound, poor air quality can also be triggered by deficient building envelopes built in extreme climates and polluted areas. Opening windows in such areas can disturb the air quality inside, bringing in pollution. In such cases, architects create openings in the secondary walls or orient partitions in ways that block the polluted air from entering directly into the space, providing a cleaner interior atmosphere.
In terms of visual comfort, most notably in commercial and educational interiors, aspects of solar glare and privacy are thoroughly taken into consideration during the design process. Based on the requirements of each space and its geographic location, architects are sometimes required to block out direct sunlight and illuminate the space through indirect natural light. This is achieved via different design solutions such as translucent secondary walls, perforated partitions, and double-height ceilings, solutions that maintain a visually-coherent interior space without compromising its lighting needs.
Second Home Holland Park / Selgascano
Into the Wall House / bergmeisterwolf architekten
House with Indoor Garden / Hiroshi Kinoshita and Associates
Design and Aesthetics
In terms of aesthetics and spatial narrative, architects have been introducing independent volumes within their built spaces that visually stand out from the rest of the interior while maintaining a sense of dialogue with it. Along with their color or material difference, this juxtaposition serves as a visual translation of their functional distinction as well. These interventions are often seen in open plan offices which require private areas for meetings or individual work, or at shared commercial spaces that feature several unique shops under the same roof.
Coroflot's Mobile Work Unit / LOS OSOS
Wet Beast Office / Studioninedots
Authentic Studios / Lorcan O’Herlihy Architects
LVWA Bookstore / Studio YUDA + Studio NOR
Hungry Man Productions / FreelandBuck
Find more interiors within interiors in this My ArchDaily folder created by the author.
This article is part of an ArchDaily series that explores features of interior architecture, from our own database of projects. Every month, we will highlight how architects and designers are utilizing new elements, new characteristics and new signatures in interior spaces around the world. As always, at ArchDaily, we highly appreciate the input of our readers. If you think we should mention specific ideas, please submit your suggestions.
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