Modular in Milan
9th April 2019

Modular in Milan

MultiPly, a ten-metre high, carbon-neutral pavilion made entirely of American tulipwood, opens to the public in the courtyard of the Universita Degli Studi di Milano (University of Milan) on 8 April, and it will remain there until 19 April as part of the curated Interni Human Spaces exhibition for Milan Design Week (Fuorisalone).

The installation was originally one of the Landmark Projects as part of the London Design Festival and shown in the Sackler Courtyard of the V&A in London in September 2018.

This ground-breaking collaboration between Waugh Thistleton Architects, the American Hardwood Export Council (AHEC), ARUP, and SEAM illustrates how modular cross-laminated construction in hardwood is a viable solution to the current housing crisis, and its new inception in Italy shows how easily it can be reconfigured to meet the users’ needs.

The main ambition of this project is to publicly debate how environmental challenges can be addressed through innovative, affordable construction,” says Andrew Waugh, co-founder of Waugh Thistleton Architects, a studio that has been at the forefront of engineered timber construction for decades. “We are at a crisis point in terms of CO2 emissions and we believe that building in a versatile, sustainable material, such as tulipwood, is an important way of addressing this issue.” 

Waugh Thistleton Architects have been pioneering innovative uses of wood in construction for decades. MultiPly explores a new, more sustainable way of building, bringing together a readily available carbon-negative material – American tulipwood – with modular design,” says David Venables, European Director of the American Hardwood Export Council (AHEC).

The point of this project is to show that modular, affordable construction, en masse, in timber, is possible, especially when you have reusable panels. The new structure is responding to its new environment, and will provide an extraordinary visitor experience and views of the historic courtyard in Milan.

The 40m3 of tulipwood that make up MultiPly store the equivalent of 28 tonnes of carbon dioxide and are replaced with natural growth in the American forest in five minutes.  

MultiPly is comprised of a maze-like series of interconnected spaces that overlap and intertwine. It has been conceived and constructed to encourage visitors to re-think the way we design and build our homes and cities.

The three-dimensional structure is built out of a flexible system, made of 16 modules of American tulipwood CLT, with digitally fabricated joints. Like a piece of flat-packed furniture, the pavilion arrived as a kit of parts and has quietly and efficiently been assembled in under a week.

The pavilion demonstrates how, through using engineered timber and modular construction, buildings can be deconstructed, reconfigured and repurposed at the end of their life. Because it is built out of modules, the pavilion has easily been taken apart in London and reassembled in a completely new configuration in Milan.

Italian architects are just as enthusiastic about timber construction, and its potential, as we are in the UK. We are on the cusp of getting European CLT industries to see the commercial viability of hardwood CLT as a more premium performance product, but as part of the mix of engineered timber materials used in construction. When Andrew Waugh talks about the construction revolution he’s talking about the whole palette of different systems in timber,” adds Venables.

Bringing MultiPly to Milan in a new configuration brought with it new challenges,” says Simon Bateman, Structural Engineer at ARUP.We were building higher than we did in London, from a narrower base, and on a windier site: this meant that the first priority was checking that the structure would stay stable in the wind. We then had to thoroughly review the fixings between the boxes for the new configuration, and add new ones where necessary, which was relatively straightforward due to the modular form. We had to achieve all this in a very short timescale with us going from initial concepts to seeing the boxes arrive on site in only eight weeks. We were still able to come up with a structure that had all of the features which made the original MultiPly so much fun, including boxes which appear to defy gravity and the vertical maze.”

Tulipwood is sourced from the United States, where the hardwood forest area is expanding at a rate of one football pitch every minute, and already exceeds 110 million hectares, equivalent to the combined area of France and Spain. This makes the material both sustainable and environmentally friendly, especially as it is one of the most abundant American hardwoods – accounting for 7.7% of the total standing volume in U.S. hardwood forests. Every year, even after harvest, the volume of tulipwood in the U.S. forest grows by 19 million m3, the equivalent of over 19 Olympic swimming pools per day.


During the day, the ten-metre high American tulipwood installation promises to be fun and playful. The labyrinthine spaces lead visitors through a series of stairs, corridors and open spaces, inviting them to explore the potential of wood in architecture. In the evenings, with subtle lighting designed by SEAM, the pavilion becomes a quiet and contemplative space, allowing visitors to reflect on the beauty of its natural material.

Marci Song, director of SEAM, commented, “We have worked on numerous installations with AHEC and their talented designers who push the limits of materiality and structural integrity of timber. As an art piece and architectural structure, we are challenged by the way in which we light each sculptural pavilion and how to bring a level of engagement and participation of the visitor through lighting and light interaction at night time. For the Milano Fuorisalone, the setting of the pavilion in the Università degli Studi di Milano Courtyard is directly adjacent to the facades. This posed new challenges on how the reconfigured boxes are experienced and how they will appear from ground level within the courtyard and from the upper colonnade level.”

Cenan Afsarpour, designer at SEAM, adds, “Developing the lighting scheme was intertwined with architectural adjustments; not only are all passageways lit, but now, all openings which face the courtyard too. In order to achieve a new identity but with a similar detail, the programming of sequential light play was a key development. Once switched on, the lighting will cycle through a sequence of scenes which were designed and programmed specifically for this occasion. It was the arrangement of the boxes and their visual relationship with the courtyard that determined the sequences, they aim to accentuate the verticality of the pavilion and provide warm glows to the newly accessible areas.”


MultiPly uses a wood engineering technique known as cross-laminating, where timber planks are laid perpendicular to one another and glued together to form very strong, stiff and stable panels.

Cross laminated timber (CLT) has traditionally been made of softwood trees. However, together with Arup, AHEC have been experimenting with CLT made from fast-grown U.S. tulipwood for the past decade.

The research and projects undertaken have proven that weight for weight, tulipwood CLT is stronger than steel and concrete and can be machined to incredibly high tolerances. It is ideal for prefabrication and rapid assembly, which reduces construction times by around 30%. Tulipwood is an inexpensive and easy to machine hardwood that is incredibly strong for its weight.

The use of tulipwood CLT means that large-scale timber buildings can be constructed without the use of concrete or steel. These properties, together with its dramatic marble-like appearance, make tulipwood a perfect pioneer hardwood for innovative timber construction.

Tulipwood planks are imported from the U.S., but the panels for MultiPly have been manufactured in the Construction Scotland Innovation Centre (CSIC). MultiPly is the very first structure made from UK manufactured hardwood CLT.

Visit MultiPly

Monday 8th to Sunday 14th April 10:00 – 24:00

Monday 15th to Friday 19th April 10:00 – 22:00