IKOSI-One Pavilion — Investment Pitch

Structural Logic

Geometry as Structure

The icosidodecahedron is one of only thirteen Archimedean solids — the rarest class of convex polyhedra, each vertex-transitive with two or more types of regular polygon faces. It possesses 30 vertices, 60 edges, and 32 faces (20 equilateral triangles and 12 regular pentagons). IKOSI-One uses a uniform 6-metre edge length throughout its entire exoskeleton, meaning every structural member is identical in specification.

At pavilion scale the geometric logic is even more potent: 360 metres of CHS tubular steel — 4.86 tonnes of circular hollow section — spans a 16.52-metre building across four occupied floors. The near-spherical form distributes wind loading with no flat facades — the estimated drag coefficient of 0.65–0.75 is roughly half that of a conventional square tower.

The solid has 32 faces, but only 31 become bespoke cassettes: the base pentagon is the ground slab. The 31-panel envelope (20 triangular, 11 pentagonal) is a set of sealed, pre-fabricated units with integrated thermal performance, waterproofing, and structural attachment — enabling rapid on-site assembly onto the pre-erected steel frame.

Structural Efficiency
4.86 tonnes of tubular steel — 360 m of CHS — for a 16.52m, 4-storey building. Homogeneous load distribution across all 60 members — no eccentric joints.

Demountable Design
Bolted connections at all 30 nodes. The entire frame can be erected, dismantled, and re-erected — circular economy by geometry.

Wind Performance
Cd 0.65–0.75 vs. 1.1–1.3 for rectilinear buildings. No stagnation pressure on any facade — reduced cladding and structural loads.

Capital Expenditure

Financial Overview

The total build cost of £3,591,600 reflects a proof-of-concept prototype — a first-of-kind pavilion where every cassette, node, and connection detail is bespoke. At £5,415/m² gross slab area (£7,696/m² on 466.7 m² usable) this sits at the premium end of pavilion construction, but Ikosi - Geometric Intelligence projects a 30–40% reduction in volume production through standardised tooling and repeat fabrication.

The largest cost centres are the exoskeleton frame (£691k) — the 30 cast nodes, 60 CHS members and the CLT core — and the bespoke façade cassettes (£595k), now led by the 11 ETFE pentagon cushions that form the pavilion’s primary daylighting. Together these constitute the geometric identity of the building.

Switching the central spine from a reinforced-concrete cylinder to a CLT decagonal core — with CLT floors at F1–F3 — saves £269,644 (−7.0%) against the baseline of £3.86M, while cutting mass and embodied carbon. A 20% contingency (£599k) reflects genuine prototype risk on a novel-form assembly.

£2,627k Construction (A–I)

+£366k Design Fees

+£599k Contingency (20%)

£3,592k Total Build Cost

Market Context

Pavilion Benchmarks

Project	Total Cost	Cost / m²	Notes
UK Expo 2025 Osaka Pavilion	~£7.0M	~£8,750/m²	National pavilion, temporary, fully serviced exhibition programme
IKOSI-One Pavilion	£3.59M	£5,415/m²	← OUR PROJECT — proof-of-concept icosidodecahedral pavilion (gross slab basis)
Serpentine Pavilion (typical)	~£1.5M	~£7,500/m²	Single-storey temporary pavilion, ~200 m², Kensington Gardens
Antepavilion (typical)	~£100k	~£3,300/m²	Small-scale experimental structure, ~30 m², Hoxton

38% Below Expo Rate
At £5,415/m² gross IKOSI-One costs materially less per square metre than a typical national expo pavilion, while delivering 4 occupied storeys and a permanent-capable structure.

3× The Space
At 466.7 m² usable across 4 floors, IKOSI-One provides over twice the usable area of a Serpentine Pavilion within a compact pentagonal footprint of just 62 m².

Volume Production Path
The proof-of-concept premium of 30–40% is recoverable in series production. At volume, unit cost is projected at £3,000–3,200/m² gross — competitive with bespoke commercial pavilions.

Engineering Innovation

Materials & Technology

Cast Steel Nodes

Thirty degree-4 junction crowns — each a precision-cast steel sphere with four CHS stub connections. Factory-applied intumescent coating to R60 fire rating.

∅580mm cast steel sphere
≈183 kg per node, 5.49 tonnes total
4 socket connections per node
Intumescent DFT 30–60mm (factory applied)
Aluminium node collars with EPDM gaskets

CHS Tubular Members

Sixty identical circular hollow section members at 6m length. Bolted connections enable full demountability — the frame can be erected, dismantled, and re-erected without material loss.

Ø114.3mm OD, 5.0mm wall thickness
6m uniform length (all 60 identical)
360m total CHS, 4.86 tonnes of tubular steel
Bolted end connections for demountability
Intumescent coating to R60 standard

Bespoke Cassettes

31 sealed, pre-fabricated facade panels (20 triangular, 11 pentagonal). Each uniquely oriented — parametric BIM + CNC fabrication ensures precision fit to the steel frame.

11 pentagonal ETFE cushions (daylighting)
15 double-glazed triangles + 5 apex PV triangles
U-value 0.25–0.30 W/m²K target
Elastomeric gaskets + silicone sealant (Class 100)
Parametric BIM (Rhinoceros/Revit), 20–25 yr lifecycle

Environmental Performance

Circular Economy

Full Demountability

Every connection is bolted, not welded. The entire steel exoskeleton — 30 cast nodes and 60 tubular members — can be dismantled, transported, and re-erected with zero material loss — circular economy by design.

Minimal Material

4.86 tonnes of tubular steel for a 16.52m building. The icosidodecahedral geometry achieves the lowest surface-to-volume ratio, minimising both embodied carbon and cladding material.

Carbon-Negative Core

The CLT decagonal core replaces 117 tonnes of concrete with 15 tonnes of timber — removing 18 tonnes of CO₂ from manufacture and storing a further 24 tonnes of atmospheric carbon in the wood. A net swing of 42 tonnes from a single decision.

Wind Efficiency

The spherical form eliminates flat facades. Cd 0.65–0.75 halves stagnation pressure compared to rectilinear buildings, reducing structural steel weight and cladding fixings throughout.

Embodied Carbon — RICS WLCA, Scenario C

208 tCO₂e Whole-Building A1–A3
(446 kg/m²)

117 tCO₂e Including Biogenic
(250 kg/m²)

−42 tCO₂e Net Core Swing
(CLT vs. RC)

~55% Cladding Share
of Total Carbon

Swapping the reinforced-concrete core for a CLT decagonal core removes 18 tonnes of manufacturing CO₂ and stores a further 24 tonnes of atmospheric carbon in the timber — a 42-tonne net swing from one design decision. Whole-building embodied carbon is 208 tCO₂e at A1–A3, or 117 tCO₂e once biogenic sequestration is counted. The aluminium-framed cladding is now the dominant element (~55%) and the primary Stage 2 reduction target.

Delivery Programme

Programme Overview

Weeks 1–2 Site Prep & Foundations
(5 Pad Footings)

Weeks 1–14 Node Fabrication
(Off-Site, Parallel)

Weeks 3–8 RC Core Construction
(Slipformed)

Weeks 15–22 Steel Frame Erection
(3-Phase Assembly)

Weeks 22–30 Cassette Cladding
& Fit-Out

Node Fabrication

14 Weeks

Off-site, parallel to ground works

On-Site Assembly

12–16 Weeks

Frame + cladding + fit-out

Total Programme

~30 Weeks

Fabrication start to handover

Enquiries

IKOSI-One is a proof-of-concept for a new class of mathematical architecture — demountable, circular, and structurally efficient at any scale.

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