The Poplar Revolution

Abstract

This project investigates the role that poplar timber can play in the construction sector of the 21st century. The project brings together existing research while investigating how and where poplar timber can be applied in the design of a rooftop extension for the former warehouse d’Peliekaan in Amsterdam. With the main research question “Does poplar timber have potential in the construction sector of the 21st century?”, the research focuses on the possibilities and considerations of building and designing with poplar. The design seeks to apply poplar in places where it makes sense, thereby determining the role of poplar timber in the construction sector.

The project demonstrates, through both research and design, the potential for using poplar in structural applications as well as for interior and façade finishes. The research shows that, depending on the sub-variety, poplar can be used as a raw material in almost all mass timber products. Furthermore, poplar timber can be easily modified for use outside the waterproof layer of structures. In the design, poplar timber has been used structurally as laminated studs in a timber frame construction, in a glulam post-and-beam construction, and in a glulam truss bridge and tower. Laminating and finger-jointing poplar ensures that irregularities in the wood structure of the hardwood are removed as much as possible, thereby achieving an expected strength class of C22. For use outside the waterproof barrier, thermal modification appears to be the best option for cladding in the design, while acetylation has been used for the structural application of poplar outside the waterproof barrier.

The design utilises a 2D timber frame structure and a 1D post-and-beam structure. The choice of these systems was based on the use of poplar and the different functions within the design. To introduce vertical adaptability into the 2D timber frame system, principles from balloon framing have been reintroduced by hanging the floor between the walls. The issues the system has with building physics (fire risks and acoustics) have been addressed by creating a modern interpretation of the system using principles from platform framing.

The use of poplar as a building material has influenced the architecture in terms of the choice of structural system and the anatomy of the façade. In this way, the overhang, intended to protect the poplar façade, has become a characteristic feature in the architecture. However, poplar appears to have little influence on the architecture in general and is perfectly suitable as a building material, differing little from other traditionally used timber species such as spruce.