Project : Architecture
The public spaces are interconnected in plan but still separated by changes in levels and differing roof profiles.
Tacit Struggle: Converging Architectural Experience and Sustainable Strategies
John Hong (professor, Seoul National University)
With the recent institutionalization of sustainability earmarked by the advent of the LEED scoring system in the mid-1990’s, there has constantly been a tacit struggle between energy performance and architectural form. ‘Building Science’ has accelerated as an autonomous discipline and its major components of envelope and mechanical systems have become its most powerful signifiers. Exposed solar panels and super-insulated walls have come to represent architecture’s advocacy of environmental design as an agenda, becoming a kind of semantic stand-in for the politics that the building represents. In an attempt to reclaim architecture’s position in generating form and refining typology, Tung House converges on active and passive sustainability strategies with architectural sequence and space in the creation of a zero-energy dwelling. Located on a strictly regulated and wooded preservation area in Massachusetts, the double challenge was to maintain the existing physical conditions of the site while maximizing the potential for energy generation in a northerly climate where sunlight is less abundant.
Because of ‘buffer zones’ protecting the wetlands near the property, the relatively large parcel of land contained only a small buildable area. While the massing adheres to these tight setback restrictions, the roof breaks free of the orthogonal geometry to optimize the orientation of the solar panels for the active generation of electricity and hot water. The 36 PV panels provide over 9-kW of power in the summer providing an excess of energy that is then transferred back into the municipal power grid. In the wintertime where less sunlight is available, the system equalizes the use of energy by also relying on three hot-water solar panels that provide the heating for the hydronic radiant floor systems. The specific calibration of the roof overhangs also provides passive energy solutions: their geometry shades the interior from the summer sun while allowing winter sunlight in for supplemental heating. In terms of the building profile, decoupling the roof geometry from the building mass creates a new typological variation of the traditional pitched roofs seen in the area. Viewed from the front, the massing appears as a compact barn-like profile, while from the backyard the same roof appears as cantilevered wings that provide shelter for social activities connecting house and landscape.
As the city ordinance body strictly limited disturbance of the existing site, the orientation of the massing also minimizes excavation. The section of the house follows the site’s natural contours, creating a split-level condition of half-levels. The result is a continuous experience of public, semi-public, and private spaces. As one enters, a view directly connects the front of the house to the preserved natural landscape of the backyard. An open stair becomes the communicating core of the house: a half-level down takes one to a large loft-like public area containing living, kitchen, dining, and play areas. These directly connect to the landscape through large swing doors that erode the corners of the room. Meanwhile, a half-level up connects to a hovering mezzanine with a craft and play area that is visually connected to but private from the living areas directly below it.
The double height living area invites views of the tall trees of the preservation areas beyond. The corner doors extend the activities to an adjacent deck.
By matching the existing sloped site, the house is organized in half-levels creating a constant flow between spaces.
Even as the house is open, rather than presented as one undifferentiated volume, the ceiling height varies drastically, defining diverse areas of use. At the upper levels, the rotated roof creates dynamic relationships between the regularity of rectangular rooms and the irregularity of the varied ceiling planes. It constantly and subtly ‘unsettles’ the occupant, suggesting varying perspectives, movements, and lighting conditions that change with one’s specific position.
Beyond the experiential level, the section is also integral to the passive and active ventilation strategies. In the summer months, natural cooling is provided by stack ventilation where automated skylights draw cooler air from the lower regions of the house releasing the hotter air through the roof. Similarly, in the winter, the system is engineered so that radiant flooring only needs to be provided on the lower levels: rising heat is vented to the upper private level through low-energy consuming fans rather than large ducted systems. The implementation of this optimized HVAC system is critical also to minimize construction costs.
Instead of incorporatig sustainable strategies separately applied to the architecture after the architectural logic of the project is set, the Tung House is a small-scale example of how the convergence of building science and spatial relationships can create something more than the sum of its parts. In the case of the Tung House, the decoupling of the roof from the programmatic volume aims to extend both it’s technical and experiential aspects. For the former, an active solar performance and the use of daylighting for passive energy is optimized. For the latter, the typological ‘play’ of the traditional pitched roof form is turned into something slightly odd or incidental that transforms expectations when viewed from the exterior. From the interior, the roof form creates differentiation and a subtle discontinuity within an otherwise open volume.
Overhangs produced by the solar orientation of the roof are also used to shelter openings to the surrounding landscape.
The double height entry connects the front and back, exterior and interior, of the house. As the north side has few opening for insulation purposes, a monolithic appearance is intentionally sought.
John Hong AIA, LEED AP is an architect and professor at Seoul National University and the director of design lab Project : Architecture. Prior to joining the faculty at SNU, he was co-principal at the critically acclaimed firm SsD (2004 – 15) and professor in Practice at the Harvard GSD (2006 – 14). His work has been exhibited at international venues including the 2014/2016 Venice Biennale and published in major media such as Architectural Record, Metropolis Magazine, The New Yorker and SPACE. His built work has received fifteen AIA awards, Architectural Record’s Design Vanguard, the Emerging Voices Award from the Architectural League NY, to name a few. His most notable writings include the books, Convergent Flux: Contemporary Architecture and Urbanism in Korea, (2012) and Fragments of a New Housing Language: Contemporary Urban Housing in Korea (2016). He received his Master’s in Architecture with Distinction from the Harvard Graduate School of Design and a Bachelor’s in Science in Architecture with Honors from the University of Virginia.
While the massing follows the setbacks, the roof is rotated to optimize for solar energy. The profile of the house is cladded in white cement board panels as a full-scale diagram of the way the traditional pitched-roof typology is distorted.
Architect: Project : Architecture (John Hong)
Design team: Jinhee Park (SsD), Taylor Harper, Daniel Carlson, Hyein Kim, Kiwon Jeon, Victor Michel, Yufeng Zheng
Location: Lincoln, Massachusetts, USA
Site area: 3,995㎡
Building area: 235㎡
Gross floor area: 353㎡
Building scope: B1, 2F
Building to land ratio: 5.88%
Floor area ratio: 8.83%
Structure: wood platform framing and glulam
Exterior finishing: fiber cement board, standing seam aluminum
Structural engineer: Evan Hankin
Mechanical and electrical engineer: Peter Osowski, Vanguard Energy Partners
Design period: Mar. 2014 – June 2015
Construction period: Nov. 2015 – June 2017
edited by Kim Narae | photographed by John Hong | materials provided by Project : Architecture