music players surround us with auditory walls; and Airbnb instantly converts homes into hotels. The entire field of urban informatics is rife with many such examples. What separates the newly emerging efforts, however, is the explicit intent to inject the physical built environment—made of glass, concrete, and steel—with the plasticity/ interactivity of digital bits.

Within such nascent efforts, I have identified responsive, augmented, and printable architecture as the three key technical approaches that I predict will serve as the main drivers of the gradual digitization of architectural space.

RESPONSIVE ARCHITECTURE

Responsive architecture refers to a
class of architectural structures that
can dynamically alter their shapes
and/or appearances using kinetic
transformation mechanisms, large-scale
LED arrays, and other technologies. R

properties of digital media.

In recent HCI literature (including some of my own work), as well as in cutting-edge architectural practice, we can see a group of emerging, but still largely isolated, efforts targeting precisely that goal. Here, I am not talking about some far-fetched efforts to create entire buildings/cities out of ceaselessly shape-shifting programmable matter. Rather, what I am pointing to is a steady pace of innovations occurring in heterogeneous technical domains that are collectively chipping away at the longstanding stability of the architectural environment—eventually, it seems, leading to the experience that we are living within a world of habitable bits (or, to use a term from my earlier publication, living in synthetic space [ 2]).

To be fair, there already exist a
number of technologies that manipulate
space. Calling someone on the phone
instantly compresses space; portable
The label does not apply to input-
only systems (wide deployment of
surveillance cameras do not qualify)
and requires some form of digital output
capability, often involving dynamic
adaptation to input (Figure 2).

Among architects, the concept of responsive architecture is not new (an early seminal work in this area can be found in Soft Architecture Machines by Nicholas Negroponte), and there already exist numerous built examples such as revolving restaurants, retractable stadium roofs, media facades, and so on. (A rare instance of responsive architecture built for domestic use can be found in Maison à Bordeaux by Rem Koolhaas.) Although fantastical visions such as Archigram’s Walking City will likely remain fantasies for the foreseeable future due to the immense cost, recent advances in digital design/prototyping tools (e.g., Arduino, Grasshopper) are rapidly dismantling many of the traditional hurdles associated with this domain. This is leading to increased deployments of responsive architecture, particularly in exhibitions and other major events where its attention-grabbing potential is highly appreciated; Asif Khan’s kinetic facade exhibited at the 2014 Sochi Olympics is one recent example.

On the other hand, while HCI’s recent fascination with shape-shifting user interfaces (or radical atoms [ 3], as Hiroshi Ishii calls them) is making kinetic architecture/furniture an increasingly viable topic of research— the undulating coMotion bench by Grönvall et al. being one prominent example—the HCI community so far has not made many inroads into responsive architecture per se. (One of the few exceptions to this may be works exploring large-scale interactive surfaces, which have long been a staple in HCI research.)

Several of my own projects have dealt with responsive architecture. For example, in 2013 I teamed up with a group of architects to build MIMMI (Figure 3), a large-scale installation that responds to the current “mood” of the city (obtained by probing Twitter feeds of citizens) through light, mist, and sound. Another example is Whirlstools (Figure 4), an unbuilt concept for a kinetic furniture system that discreetly encourages communication between strangers through subtle alterations of physical

Figure 1. A hypothetical “fully-digitized” architectural space.

Change!