Kagome Project
Basic information
Project Title
Kagome Project
Full project title
Kagome Project
Category
Reconnecting with nature
Project Description
An elastic gridshell is an efficient constructive typology for crossing large spans with little material. A flat elastic grid is built before buckling the structure into shape, in active and post-formed bending.
Kagome is made 100% of wood : its laths are interlaced to form a japanese traditionnal pattern, called Kagome, which makes the structure naturally braced. This pavillion is standing at the Parc de la Butte du Chapeau Rouge, a public square in the working-class area of Paris.
Kagome is made 100% of wood : its laths are interlaced to form a japanese traditionnal pattern, called Kagome, which makes the structure naturally braced. This pavillion is standing at the Parc de la Butte du Chapeau Rouge, a public square in the working-class area of Paris.
Geographical Scope
National
Project Region
Paris, France
Urban or rural issues
Mainly urban
Physical or other transformations
It refers to other types of transformations (soft investment)
EU Programme or fund
No
Description of the project
Summary
Kagome project was designed, computed and built by a group of students from ENSA Paris La Villette (FRANCE), supervised by Marc LEYRAL and Quentin CHEF. Kagome is part of a constellation of projects imagined by the collective Construire l'Architecture. One goal of this association is to give young architects access to complex engineering design through open-source tools and building at scale 1. Calculation was permitted thanks to ELASTICA tool, an algorithm developped during previous experiences of such a type.
Key objectives for sustainability
Building a gridshell obliges to carefully chose the section and the material of the laths : they have to be thick and rigid to resist but they need to be thin and tender to permit the buckling phase for erection (the grid is built flat at first). Students chose a very specific Ash tree Section for this purpose but, due to Covid crisis and Ukraine war, material was not available. In this context, they looked in a Ressourcerie, a local shop that provides reused material. An old theater setting was dismantled in panels, the panels were cut in pieces to become the laths of the pavillions. A full timber pavillion became a full RE-USED timber pavillion. Even more sustainable !
Key objectives for aesthetics and quality
When Elastica was achieved in 2021 (the old "cousin" of Kagome), there were supposed to be 2 pavillions facing one another. But due to lack of resource, only one pavillion was built in 2021. Now Kagome completes the duo and restablish the perspective. At the top of the hill, the couple of timber structures offer a great perspective between the trees to enjoy the scenery of la Plaine Saint Denis.
Key objectives for inclusion
The Parc de la Butte du Chapeau Rouge is located in the 19ème arrondissement of Paris, in a rather poor neighborhood. Under Kagome and Elastica, people from all origins come and discuss : childrens, young adults, old people. The project becomes a cover for the sun or for the wind ; you can play hide and seek or practice yoga ; or just sit on the bench and watch the leaf fall.
Results in relation to category
Kagome is the second time we use the ELASTICA algorithm (dynamic relaxation made easy for architects students) to build a gridshell in a public park. We need to give the credit to the students, who, on a very short notice, were able to : design, calculate, obtain material (with a restricted budget), prefabricate, transport, build and give access to the public.
This kind of exercise (practicing at scale 1) could be (and must be!) reproduced.
This kind of exercise (practicing at scale 1) could be (and must be!) reproduced.
How Citizens benefit
The Parc de la Butte du Chapeau Rouge is a beautiful place but it suffers from the lack of equipment (no benches…) and landmarks (no fountains…). All the projects that Construire l'Architecture and ENSA Paris La Villette put in the parc (Kagome is the 4th one) are noticed by the people who live nearby and we receive very good feedback !
Physical or other transformations
It refers to other types of transformations (soft investment)
Innovative character
The design and structural analysis of such a structure requires a stage of form finding that can mainly be done: (1) With a physical model: either by a suspended net method, or an active bending model; (2) With a numerical model performed by dynamic relaxation. All these solutions have various biases and assumptions that make them reflect more or less the reality. These three methods have been applied by Happold and Liddell during the design of the Frei Otto’s Mannheim Gridshell which has allowed us to compare the results, and to highlight the significant differences between digital and physical models. Based on our own algorithm called ELASTICA, our study focuses on: (1) Comparing the results of the ELASTICA’s numerical models to load tests on physical models; (2) The identification of the various factors that can influence the results and explain the observed differences, some of which are then studied; (3) Applying the results to build a full-scale interlaced lattice elastic gridshell based on the Japanese Kagome pattern.
Disciplines/knowledge reflected
We believe in integrative design : structure, architecture, sustainibility, beauty, function, optimization of material… everything need to work together from the beginning if you want to success. They are not features you can add once design is done.
The attached PDF describes the process more precisely (Journal of Civil Engineering and Architecture (#16, April 2022), David Publishing).
The attached PDF describes the process more precisely (Journal of Civil Engineering and Architecture (#16, April 2022), David Publishing).
Methodology used
Desiging Kagome started with an exploration phase of scale models (1:10 and 1:2) of traditionnal gridhsells. We compared them to numerical results thanks to our algorithm ELASTICA. It led us to discover and explain a few biases that exist when working on scale models. This achievment in research was pubished in a scientific journal (attached to our submission).
How stakeholders are engaged
The CityHall of Paris and Paris 19 are partners form the beginning : local services help to achieve the building and inauguration, they make it possible to leave the pavillions for several months (security, maintenance…), the make plants grow on the structure. Without them and without the benevolence of the citizens of the park, nothing would have been possible.
Global challenges
As explained in the previsous paragraphs, Kagome succeeded thanks to :
- students efforts during two semesters of work
- local store providing the wood (re-use timber)
- local services (City Hall) allowing our structures to be displayed in the park for a long time and for everyone to see it
- citizens of Paris 19ème appreciating the works and taking good care of it
- students efforts during two semesters of work
- local store providing the wood (re-use timber)
- local services (City Hall) allowing our structures to be displayed in the park for a long time and for everyone to see it
- citizens of Paris 19ème appreciating the works and taking good care of it
Learning transferred to other parties
Theses two innovations are completely reproductible and our website provides all the tools to do so :
- design a full timber post formed elastic gridsheel (no steel bracing)
- estimate the biases between scale model, reality and numerical models
- design a full timber post formed elastic gridsheel (no steel bracing)
- estimate the biases between scale model, reality and numerical models
