Theoretical Basis of Structural Strategy for a High School

Responding to Spatial Complexity Through Integrated Structural Strategy

The structural design of the proposed high school reflects a sensitive and rational response to the building’s spatial and functional requirements within a dense urban context. The strategy of a mixed reinforced concrete and steel frame responds not only to performance and environmental conditions typical of a temperate climate but also to the need for acoustic isolation, flexibility of internal arrangements, and constructability (Lawson et al., 2014). The building's form—two asymmetrical rectilinear blocks flanking a central circulation spine—is both a constraint and an opportunity. It enables the formation of an integrated structure where load-bearing elements and servicing strategies are co-located and where the spatial configuration directly informs structural articulation (Schodek et al., 2005).

Central Circulation Spine as Structural Organizer

The circulation spine is central to the structural logic of the building. In each design option, this central zone features floor slab openings to accommodate staircases and vertical movement. These openings are strategically positioned so that edge support is provided by beams spanning the corridor’s width. This approach reduces the need for additional vertical supports at the void edges, maintaining spatial clarity and visual openness (Allen and Iano, 2019). The corridor acts as a longitudinal service trench, and by separating structural and service zones, the design avoids deep beams, enhancing construction speed and lowering cost (Macdonald, 2001). Structurally, the corridor spine can serve as a shear and stiffness zone, where lateral loads are resisted through diaphragm action across the slab, potentially supplemented by stair and lift cores (Engel, 2007).

Asymmetry and Differentiation Across the Plan

The plan is highly indented and asymmetrical, with different profiles along each long elevation. This results from varying classroom sizes and functions, offering unique structural challenges: Indents in the floor plates provide opportunities for structural rhythm—the positioning of perimeter columns at the corners of each classroom allows the indents to act as glazed structural bays, enhancing daylight penetration and visual connectivity (Ching and Adams, 2014). The indents also allow the expression of a repeating structural grid across an otherwise complex footprint, enabling prefabrication and modularisation of structural components (Lawson, 2010).

Column Arrangement and Structural Grid

The strategy of using a regular grid with doubled column lines—placing columns at the corners of teaching spaces—enables flexibility while maintaining structural regularity: This layout reduces structural spans and allows for the economical use of floor slab systems such as reinforced concrete flat slabs or composite steel decking systems (Ogunbode and Wilkinson, 2020). Columns aligned with internal walls reduce the need for freestanding posts, simplifying load paths while integrating structure with architectural partitioning (Macdonald, 2001). The repetition of the grid vertically throughout the building allows for consistent load transfer and minimizes the need for complex transfer structures, which would otherwise increase cost and construction complexity (Schodek et al., 2005).

Inclined Columns and Cantilevered Volumes

A particularly expressive element in the structural design is the use of inclined columns to support cantilevered upper-level classrooms and large oriel windows: These inclined columns resolve eccentric load paths, directing forces back into the primary vertical structural grid while maintaining the architectural intent of suspended mass and unobstructed views (Engel, 2007). By avoiding columns below the projecting bays, the design achieves a visual lightness and spatial openness along the street frontage—a strategy that is structurally enabled by designing cantilevered slabs to act as moment-resisting structures (Allen and Iano, 2019). Inclined columns must be carefully detailed to avoid introducing unwanted horizontal thrusts into the slab system, often requiring moment-resisting connections or hidden ties (Salvadori and Heller, 2002).

Structural Integration of Acoustic and Functional Requirements

The hybrid structural strategy—concrete at lower levels and steel at upper levels—reflects both acoustic performance requirements and construction sequencing considerations: Reinforced concrete offers superior sound attenuation, making it suitable for music practice rooms and performance areas located at lower levels (Cowan, 2000), Steel construction at the upper levels allows lighter, faster installation, and the ability to span longer distances over shared or open-plan teaching areas, including those with oriel windows (Lawson et al., 2014). The separation of structural materials by level allows functional zoning: heavy-use spaces benefit from thermal mass and robustness, while upper, lighter spaces benefit from adaptability and reduced load on foundations (Addington and Schodek, 2005).

Non-Structural Walls and Long-Term Flexibility

The decision to limit structural walls to lift enclosures, washrooms, and zones where change is unlikely ensures long-term adaptability: This approach aligns with open building theory, supporting flexibility over time without compromising structural integrity (Habraken, 1998). Partition walls can be modified, moved, or removed entirely, without affecting structural stability—facilitating future reprogramming of classroom sizes or uses (Lawson, 2010). Retaining structural load-bearing walls only at strategic locations also reduces thermal bridging and simplifies envelope detailing, particularly in a temperate climate where thermal performance is key (Givoni, 1998).

Rooflight and Bridge Integration

The bridging elements that link the two blocks across the central spine are both functional and structural: These bridges create moment frames or truss systems that connect the two parts of the building, allowing for lateral load distribution across the structure (Schodek et al., 2005). The continuous rooflight across the top of the spine requires long-span roof beams, likely in steel, which must resist uplift and support glazing systems without sag (Addington and Schodek, 2005). These structural elements double as architectural features, emphasizing transparency and connection—a theme consistent throughout the project.

References

Addington, M. and Schodek, D. (2005) Smart Materials and Technologies in Architecture. Oxford: Architectural Press.

Allen, E. and Iano, J. (2019) Fundamentals of Building Construction: Materials and Methods. 7th ed. Hoboken: Wiley.

Ching, F. D. K. and Adams, C. (2014) Building Construction Illustrated. 5th ed. Hoboken: Wiley.

Cowan, H. (2000) Handbook of Environmental Acoustics. New York: Wiley.

Engel, H. (2007) Structure Systems. 2nd ed. Ostfildern: Hatje Cantz.

Givoni, B. (1998) Climate Considerations in Building and Urban Design. New York: Wiley.

Habraken, N. J. (1998) The Structure of the Ordinary: Form and Control in the Built Environment. Cambridge, MA: MIT Press.

Lawson, B. (2010) Designing for Adaptability. Oxford: Architectural Press.

Lawson, M., Ogden, R. and Goodier, C. (2014) Design in Modular Construction. London: CRC Press.

Macdonald, A. J. (2001) Structure and Architecture. 2nd ed. Oxford: Architectural Press.

Ogunbode, E. and Wilkinson, S. (2020) Structural Design for Buildings: Learning from Failures. London: ICE Publishing.

Salvadori, M. and Heller, R. (2002) Structure in Architecture: The Building of Buildings. 3rd ed. Englewood Cliffs: Prentice Hall.

Schodek, D., Bechthold, M., Griggs, K., Kao, K. and Steinberg, M. (2005) Structures. 5th ed. Upper Saddle River, NJ: Pearson Education.