amanbh997/skills-architects/concept-design

Concept Design

Comprehensive knowledge base for architectural concept design including parti development, massing strategies, spatial organization models, concept-to-form translation, and design iteration protocols. Invoke this skill when developing early-stage design concepts, evaluating massing options, organizing spatial programs, or translating abstract design ideas into architectural form.

Section 1: Parti Development

1.1 What is a Parti?

The parti (from French "parti pris" — a decision taken) is the essential organizational diagram of a building. It is the irreducible idea that governs the relationship between program, structure, circulation, and site. Every design decision should be traceable to the parti. If a move does not reinforce the parti, it weakens the design.

A strong parti:

• Can be drawn in 30 seconds with a single line or simple shapes
• Explains the building's organization to a non-architect
• Resolves the primary design problem (access, view, climate, program)
• Generates both plan and section logic
• Remains legible in the finished building

1.2 Twelve Archetypal Parti Types

1. Linear

Diagram: A single bar or spine — all rooms arranged along one axis. Circulation runs parallel to the primary volume.

Spatial Characteristics:

• Single-loaded or double-loaded corridor organization
• Clear directionality from one end to the other
• Sequential spatial experience (A to B to C)
• Depth typically 12-18 m for natural ventilation and daylighting (single-loaded: 6-8 m; double-loaded: 12-15 m)

Programmatic Best-Fit: Museums and galleries (sequential viewing), hospitals (patient wings), schools (classroom wings), linear transit stations, waterfront promenades

Structural Implications: Repetitive bay structure perpendicular to the spine. Typical bay: 6-9 m wide x 6-12 m deep. Lateral stability via corridor walls or braced bays at intervals (every 30-40 m in steel, every 20-30 m in timber).

Exemplar Buildings:

• Neue Nationalgalerie, Berlin (Mies, 1968) — 64.8 m x 64.8 m clear-span roof on 8 cruciform columns, but the gallery below is organized as a linear sequence of rooms
• Kimbell Art Museum, Fort Worth (Kahn, 1972) — 6 parallel cycloid vaults, each 30.5 m long x 7.0 m wide, linear gallery rooms beneath

2. Courtyard

Diagram: Rooms arranged around one or more enclosed open spaces. The void is the organizing principle.

Spatial Characteristics:

• Inward-looking — the courtyard provides light, air, and a protected exterior room
• All rooms share a visual and physical connection to the open space
• Strong definition of public (courtyard) and private (perimeter rooms) zones
• Courtyard dimensions for comfortable microclimate: minimum width = 1x surrounding building height in temperate climates; 0.5x in hot climates (for shade)

Programmatic Best-Fit: Housing (traditional Islamic house, European palazzo, contemporary apartment blocks), monasteries, schools, museums, offices, civic buildings

Structural Implications: Load-bearing perimeter walls or frame structure with courtyard as structural void. Corner conditions require careful resolution (corner columns or cantilevered slabs). Typical perimeter depth: 6-12 m.

Exemplar Buildings:

• Salk Institute, La Jolla (Kahn, 1965) — two parallel lab wings flanking a travertine courtyard (61 m x 20 m) open to the Pacific, water channel on axis
• Alhambra, Granada (14th century) — Court of the Myrtles (36.6 m x 23.5 m, reflecting pool), Court of the Lions (28.5 m x 15.7 m, columned arcade, fountain)

3. Clustered

Diagram: Discrete volumes grouped by proximity and relationship, without a single dominant axis or center. Spaces are connected by short links or shared edges.

Spatial Characteristics:

• Non-hierarchical — no single dominant space or axis
• Village-like aggregation of semi-independent elements
• Interstitial spaces (between clusters) are as important as rooms themselves
• Scale range: from a cluster of rooms to a cluster of buildings

Programmatic Best-Fit: University campuses, research parks, housing communities, primary schools, conference centers, healthcare villages

Structural Implications: Each cluster can have independent structure. Connections may be lightweight (glazed links, bridges) or substantial (shared walls). Foundation design varies per cluster, advantageous on sloping or irregular sites.

Exemplar Buildings:

• Amsterdam Orphanage (van Eyck, 1960) — tartan grid of small pavilions creating an interior village, domed roofs, multiple scales from individual to collective
• Maggie's Centre, Edinburgh (Richard Murphy, 2009) — cluster of small rooms around a central kitchen, domestic scale, garden connections

4. Radial

Diagram: Elements radiating from a central point or core. Circulation moves outward from center to periphery or along concentric rings.

Spatial Characteristics:

• Strong central focal space (atrium, rotunda, hub)
• Radial wings or corridors extending outward
• Diminishing hierarchy from center to edge
• Clear orientation — the center is always identifiable
• Plan geometry: circular, hexagonal, octagonal, or triangular subdivision

Programmatic Best-Fit: Airports (central terminal with radiating concourses), hospitals (nursing hub with radiating wings), prisons (panopticon), convention centers, large-scale commercial (central food court with radiating retail wings)

Structural Implications: Central core carries vertical loads and provides lateral stability. Radiating wings can be identical (modular) or differentiated. Structural efficiency decreases at the perimeter (wider spans between radial walls). Ring beams at intersections.

Exemplar Buildings:

• Guggenheim Museum, New York (Wright, 1959) — helical ramp spiraling around a 28 m diameter central void, top-lit atrium
• Chandigarh Capitol Complex (Le Corbusier, 1952-63) — radial site plan with Assembly, Secretariat, and High Court radiating from central esplanade

5. Grid

Diagram: A regular two-directional matrix of structural bays, typically orthogonal. Program is distributed across the grid; hierarchy emerges through selective void, double-height, or density variation.

Spatial Characteristics:

• Neutral, non-directional spatial field
• Flexibility — any bay can house any function (within structural capacity)
• Hierarchy through exception: voids, double heights, material changes within the grid
• Repetitive bay dimensions provide economic efficiency

Programmatic Best-Fit: Offices (6-9 m grids), parking structures (8-10 m grids), warehouse/industrial (10-15 m grids), exhibition halls, libraries, mixed-use buildings

Structural Implications: Highly efficient — repetitive columns, beams, and floor plates. Standard grids: 6 m x 6 m (economic minimum for offices), 7.5 m x 7.5 m (popular for parking below offices), 9 m x 9 m (generous open office), 10.8 m x 10.8 m (maximum economic RC flat slab). Column sizes: 300-600 mm diameter for RC, 200-400 mm for steel, depending on load and height.

Exemplar Buildings:

• Crown Hall, IIT Chicago (Mies, 1956) — 36.6 m x 67 m clear span, 4 plate girders at 18.3 m spacing, universal space
• Sendai Mediatheque (Ito, 2001) — 50 m x 50 m, 13 tube-columns on irregular grid, 7 floor plates, each floor a different program

6. Pinwheel

Diagram: Elements rotating around a central point but not connected at center — like windmill blades or a swastika motif (in its pre-symbolic geometric sense). Four (or three) wings extending and rotating around a pivot.

Spatial Characteristics:

• Dynamic centrifugal movement outward from center
• Each wing extends toward a different landscape or context condition
• Center is often a void or transitional space
• Asymmetric balance through rotational equilibrium

Programmatic Best-Fit: Houses (each wing toward different garden aspect), small cultural buildings, pavilions, visitor centers

Structural Implications: Each wing is structurally semi-independent. Central pivot point may be a column cluster or a core. Wings typically single-story or split-level. Cantilevers at wing terminations create visual dynamism.

Exemplar Buildings:

• Barcelona Pavilion (Mies, 1929) — walls and roof planes slide past each other in a pinwheel composition, 8 cruciform chrome columns
• Brick Country House project (Mies, 1924) — unbuilt; seminal pinwheel plan with walls extending beyond the building envelope into the landscape

7. Bar

Diagram: A single rectangular volume, typically elongated (length:width > 3:1). Simpler than the linear parti — the bar is a single mass rather than rooms along a spine.

Spatial Characteristics:

• Maximum perimeter-to-area ratio (good for daylighting and ventilation)
• Clear structural logic: short-span direction perpendicular to the long axis
• Two primary facades with distinct orientations (north/south or street/garden)
• Floor plates 12-18 m deep (optimal for daylighting: daylight penetrates 2-2.5x ceiling height from facade)

Programmatic Best-Fit: Residential (apartment slabs), offices (commercial bars), laboratories (with service spine), schools (classroom bars)

Structural Implications: Repetitive cross-section. Steel or RC frame with 6-9 m bays. Lateral stability via cores at ends or intervals. For timber: CLT panels at 3.6-6 m bay spacing, typically 5-8 stories maximum.

Exemplar Buildings:

• Unite d'Habitation, Marseille (Le Corbusier, 1952) — 137 m x 24 m x 56 m, 337 apartments in a single bar, internal street, pilotis
• Narkomfin Building, Moscow (Ginzburg, 1930) — 85 m long bar, skip-stop corridor, duplex apartments, detached communal block

8. Tower

Diagram: A vertical extrusion of a compact floor plate, typically with a central or offset core. Height:width > 3:1.

Spatial Characteristics:

• Vertical stacking of repetitive floor plates
• Core as organizing element (elevators, stairs, risers, restrooms)
• Premium floors at top (views, light, prestige)
• Ground floor as public interface (lobby, retail, through-block connection)
• Core-to-perimeter distance: 9-15 m (optimal for daylighting and leasing depth in offices)

Programmatic Best-Fit: Offices (10-60+ stories), residential (15-80+ stories), hotels, mixed-use towers

Structural Implications: Core provides gravity and lateral resistance (RC shear walls 300-600 mm thick, or braced steel core). Perimeter frame: steel or RC columns at 3-4.5 m centers. Outrigger trusses at intervals for supertall (> 300 m). Floor plate efficiency: 70-82% net-to-gross (compact core = higher efficiency). Structural premium above 50 stories: 15-25% additional cost.

Exemplar Buildings:

• Seagram Building, New York (Mies + Johnson, 1958) — 38 stories, 157 m, bronze I-beam curtain wall, 27 m plaza setback
• 30 St Mary Axe, London (Foster, 2004) — 41 stories, 180 m, diagrid structure, circular plan tapering at base and top

9. Podium + Tower

Diagram: A horizontal base (podium, 2-6 stories) supporting one or more vertical towers. The podium engages the street; the tower engages the sky.

Spatial Characteristics:

• Podium: large-floor-plate programs (retail, parking, conference, amenity)
• Tower: small-floor-plate programs (residential, hotel, office)
• Podium roof as amenity deck (pool, garden, playground)
• Podium defines the streetwall; tower is set back from the podium edge (minimum 3 m for many zoning codes)

Programmatic Best-Fit: Mixed-use urban development, hotels above retail, residential above commercial, transit-oriented development

Structural Implications: Transfer structure at podium-tower interface: transfer beams (1.2-3.0 m deep) or transfer plates (600-1,200 mm thick RC) redistribute tower column loads to wider podium column grids. Podium columns at 8-10 m grids for parking; tower columns at 6-9 m grids.