Energy renovation of modern built heritage

The TRANSFORM institute recently supported the architecture firm Vurpas architects, the lead on a project for restructuring and energy renovation of the buildings of the Annecy Alps Higher School of Art (ESAAA).

© Fondation Marta Pan et André Wogenscky

ESAAA occupies a portion of the architectural complex designed and constructed between 1962 and 1974 by André Wogenscky and Louis Miquel to house the Annecy Youth and Cultural Center at the Marquisats site. This exceptional site features a steep slope facing northeast, immediate proximity to Lake Annecy, and distant views of the surrounding mountain ranges. Majestic trees inherited from the 19th-century villa park on the site enhance its landscape quality. The architectural ensemble harmonizes with the site by extending its volumes and ramps across the slope, enhancing its perception through fluid pathways and the principles of "active architecture," a concept dear to Wogenscky. The materials used, primarily raw concrete, glass, and exotic wood joinery, contribute to its minimalist aesthetic. The use of the Modulor system further ensures a sophisticated dimensional coherence that integrates construction details with the urban environment. The site is currently recognized as Remarkable Contemporary Architecture. It accommodates four distinct users: the art school, a concert hall dedicated to contemporary music, the Marquisats sports center, and a residence for students and young professionals. The Grand Annecy metropolitan area, owner of the premises occupied by ESAAA, has recently initiated a project for restructuring and energy renovation of the building, appointing the Lyon-based firm Vurpas architects as the lead of the design team.

© Vladimir de Mollerat du Jeu

Vurpas x TRANSFORM

Benefiting from extensive experience in rehabilitation projects of buildings and heritage sites, the Vurpas architectes team has accomplished remarkable work in heritage diagnostics and reconstructing the history of the buildings on the site. The initial program distribution intentions have recently been validated by the client. Remaining faithful to the principles of "active architecture" while addressing heritage and energy challenges, a new program distribution has been proposed: it strongly distinguishes between static-use programs (primarily allocated to parts of the building capable of being properly insulated) and dynamic-use programs (mostly situated where improvements to the thermal envelope can be pursued).

Following the publication of the first articles in October and December 2022 under the section « Everything Transforms » in the Tracés journal (notably "Pour une « Umbaukultur » sensible : un outil d’aide à la décision et Feuille de route pour la rénovation énergétique du patrimoine bâti), Vurpas architectes engaged the TRANSFORM institute for preliminary design phase support. The institute's expertise in balancing energy efficiency improvements with the preservation of architectural heritage, particularly from the latter half of the 20th century, motivated this collaboration.

Joint reflection

This support led to a workshop held on October 6, 2023, in Annecy. Stefanie Schwab and Reto Mosimann from the TRANSFORM institute, along with Vincent Vergain, facilitated the event. The workshop brought together several collaborators from the design team (representatives from Vurpas architects and the EGC Capaldi fluid engineering firm), members of the school's management team (including Ms. Isabelle Carlier, director of ESAAA), and user representatives (faculty, students, and school technical services). The objective of the workshop was to identify the key challenges of sustainable energy renovation applied to modern built heritage and to share the methodology developed at the TRANSFORM institute. Specific issues related to thermal renovation of ESAAA's buildings were discussed from the perspectives of energy efficiency, heritage preservation, usage requirements, and cost-effectiveness. Additionally, possibilities for energy renovation of the facades were specifically addressed.

The workshop was structured into two parts. In the morning, after an overview of the ESAAA renovation project by the lead team, Stefanie Schwab and Reto Mosimann presented strategies and methods they developed at TRANSFORM and in their professional practice for energy renovation of modern built heritage. A group tour of the building followed, allowing participants to collectively identify instances where balancing energy and heritage goals posed challenges. In the afternoon, discussions focused on finding solutions to reconcile these sometimes conflicting objectives. Workshop participants explored various approaches to thermally improve a section of the facade, using a facade detail presented at 1:20 scale for on-site examination and annotation. Multiple intervention scenarios, varying in invasiveness, were developed. Each scenario's pros and cons were evaluated based on criteria such as energy performance improvement, impact on usage, alteration of facade appearance and perception, loss of heritage significance, embodied energy, and cost-effectiveness.

This service-oriented approach by the TRANSFORM institute, an extension of its research activities, effectively disseminated energy renovation methods and strategies for modern built heritage while adapting them to a new and distinct case study different from previous examples studied.

References

— Amouroux, Dominique. André Wogenscky et Louis Miquel à Annecy. Annecy : Conseil d’Architecture, d’Urbanisme et de l’Environnement de Haute-Savoie CAUE, 2014. 
— Amouroux, Dominique. André Wogenscky. Paris : Ed. du Patrimoine / Centre des Monuments Nationaux , 2012. 
— Vurpas, phase Diagnostic Faisabilité / Hier, juillet 2022 (document non édité) 
— Vurpas, phase Diagnostic Faisabilité / Aujourd’hui, juillet 2022 (document non édité)