Digital Construction

Modelling the unmortared: how Aecom helped build the 2026 Serpentine Pavilion

The serpentine brickwork of the Serpentine Pavilion 2026 a serpentine, designed by Isabel Abascal and Alessandro Arienzo of LANZA atelier. Exterior view © LANZA atelier. Photo: Iwan Baan; courtesy Serpentine.
The serpentine brickwork of the Serpentine Pavilion 2026, designed by Isabel Abascal and Alessandro Arienzo of LANZA Atelier. Exterior view © LANZA atelier. Photo: Iwan Baan, courtesy of Serpentine

For the 13th consecutive year, Aecom has helped to deliver the Serpentine Pavilion architectural programme in London’s Kensington Gardens. Aecom provided multi-disciplinary engineering and technical advisory services for the structure, collaborating closely with the architect, the Serpentine and specialist contractor Stage One to realise the distinct design vision. Central to the structure’s design is its legacy beyond its first life and creating a structure that is fully demountable. James Wright from Aecom explains the challenges and details the tools and methods Aecom used to overcome them.

The 2026 Serpentine Pavilion, designed by Mexican architect LANZA Atelier, presents one of the most technically demanding briefs in the programme’s 25-year history. Inspired by crinkle-crankle walls in Suffolk, it features a single-brick-wide wall whose form reflects the figure of a serpent.

The Pavilion takes a centuries-old masonry tradition and asks it to do something it has never been asked to do before: come apart cleanly and be rebuilt somewhere else. Meeting that challenge required a digital workflow that stretched from parametric concept geometry all the way through to fabrication detailing, with physical testing sitting at its heart.

Aecom’s engineering process began in Rhino and Grasshopper, building upon the architect’s models, allowing the team to explore and interrogate the wall’s curved geometry in collaboration with the architects.

Understanding the geometry

The serpentine shape is not merely aesthetic: its in-plane curvature is the source of its increased lateral stiffness. Understanding the geometry from the outset was essential to interpreting how the structure would behave. Grasshopper’s parametric logic allowed the team to rapidly test variations in curve radius, pier spacing and wall height, feeding structural intuition into the architectural design process from the outset.

Screenshots from Rhino model used to inform design team on the visual impact of the buttresses on the North Wall. Image: Aecom
Screenshots from the Rhino model used to inform the design team on the visual impact of the buttresses on the North Wall. Image: Aecom

During detailed design, the analytical work shifted to SCIA Engineer for finite element analysis, by transferring the non-traditional geometry between the software. Due to the demountabilty requirements, the wall is formed of a hybrid system in which a slender steel subframe is embedded within the brick courses, with a prestress applied to the wall by steel windposts, making the bricks and steel act compositely.

Quantifying exactly how much composite action could be achieved was one of the central engineering questions.

First principles

Extract of the 2026 Pavilion from SCIA Engineer. Image: Aecom
Extract of the 2026 Pavilion from SCIA Engineer. Image: Aecom

The team used hand calculations to establish the relative stiffness of the two wall materials, the engineering brick and the slender steel windposts, giving a theoretical upper bound on the composite benefit that the bricks could contribute to the steel frame. SCIA Engineer models helped to explore the structural behaviour across the full range of scenarios, including the interaction of the geometry, differential deflections and impacts of connection releases.

However, a digital model is only as reliable as its assumptions, which for the brick-steel interaction were, by necessity, informed estimates. That is where physical testing became indispensable.

At-scale testing as calibration

To assess the composite action achieved, a full-scale test measured the stiffness of a wall segment with and without the bricks installed. Both pieces were tested under static loads parallel and perpendicular to the wall plane and under dynamic excitation.

The testing revealed something that no analysis model could: the real-world variation in brick tolerances. Traditional brick walls rely on the mortar beds to take up construction tolerances. With no mortar beds, we had to rely on the workmanship of the wall, adopting a combination of soft joints, wedges and shims to ensure the prestressing was sufficiently uniform to stabilise the walls and avoid localised brick damage.

Later, the excitation test was repeated with a heavier steel frame and the introduction of piers. This test showed a significant reduction in the wall excitation, highlighting the importance of the bricklaying workmanship, ensuring each brick is tightly wedged to the steel frame, and the wall is adequately prestressed to unlock the composite behaviour.

The testing results refined the modelling assumptions used in the finite element analysis for the connection releases and deflection results, to account for the composite action observed.

From analysis to fabrication

The architect’s 3D model was used as a basis for the contractor’s fabrication model, produced in Autodesk Inventor. This model contains the as-built information, including all connection details.

Extract from the fabrication model showing half-lap connections of the roof and wall supports and bolted top plate connections. Image: Aecom
Extract from the fabrication model showing half-lap connections of the roof and wall supports and bolted top plate connections. Image: Aecom

Details of this model were shared with the design team to simplify the review process without the use of the same native software. This process allowed us to see the connections in a 3D environment, investigating the orientation and positioning of the half-lap connections and connection points to the walls to ensure the as-built structure meets the engineering assumptions.

A challenge was to create a slender masonry wall that allows for demountability. The concept was achieved by building on full-scale testing to calibrate our computational models, determining the benefits of the prestressing and composite action within the wall. The result is a hybrid prestressed masonry solution that gains significant benefit from the wall’s curved geometry and the use of piers as a traditionally bonded wall would, but which allows the wall to be fully demountable.

What makes the 2026 Pavilion notable is not the sophistication of any digital tool, but the workflow that held these all together, from parametric modelling, finite element analysis, hand calculation, physical experiment and fabrication detailing – each informing the others.

The completed Serpentine Pavilion 2026, designed by Isabel Abascal and Alessandro Arienzo of LANZA atelier. Interior view © LANZA atelier. Photo: Iwan Baan; courtesy Serpentine.
The completed Serpentine Pavilion 2026, designed by Isabel Abascal and Alessandro Arienzo of LANZA atelier. Interior view © LANZA Atelier. Photo: Iwan Baan, courtesy Serpentine

Story for CM Digital? Get in touch via email: [email protected]

Leave a comment

Your email address will not be published. Required fields are marked *

Latest articles in Digital Construction