Roland Halbe

OBJETIVO

The main building is a wooden construction with two open office floors, standing over a parking platform behind the alley of preserved trees that shadow the sun exposure from the west. Complementary buildings containing a dining room, laboratories, storage, and sport facilities, are placed in a concrete basement with roof-gardens, forming terraces along the transversal slope of the terrain. As the ground had a poor load capacity, foundation piles were needed to base the main wood structure on as few bases as possible.
The wood structure, an assembly of prefabricated glue-lam series of beams, pillars and CLT slabs of 27 m., was designed to have repetitive elements resisting traction and compression forces connected by torsion-free joints. A squared grid of pillar arranged at a module of 8.1 m. (fit for the parking layout) supports a series of laminated beams at 0.9 m. each, that hold CLT slabs resting on a pair of double main beams anchored to the pillars.
All horizontal seismic and wind forces were countered and transferred to the ground by shear walls of reinforced concrete: transversally to the floor plan, by pairs of walls hosting a series of five staircases at 24.3 m. (27 x 0,9 m); and longitudinally, by a pair of mullions at each end of the continuous 206 m. long main wood beams formed by a series of 27 m. long (30 x 0,9 m) wood elements glued in place.

CONTEXTO

CMPC is a large Chilean company for the industry of paper and wood products, that had decided to unite in one location several facilities scattered through their forests at southern region of Chile. This project won the architectural competition by proposing a single structure —the largest wooden building in Chile— representative of the institution and, at the same time, replicable as a wood construction model.
The 6 ha. plot has a suburban location between the main Chilean expressway and the actual northern entrance avenue to Los Ángeles, in a meadow with a gentle 10% slope crossed by a row of old native trees, along a central axis remaining from the former entrance road to the city.
The program consists mainly of office areas concentrated in one main building; laboratories, storage areas, a dining room, sport facilities and six greenhouses, in separate buildings; plus, parking areas.
The regulations allowed building only in the upper part of the site and a maximum of 3 floors. The ground soil, of clay and sand, was soft to excavate but has a poor load capacity. The local climate is cold and rainy in winter and hot and dry in summer.
The preliminary project was conceived to be built in several stages without losing unity, by extending the linear layout over an initially completed groundwork. However, the company demands grew quickly during the design process and the project reached its whole extension before the construction started, being finally completed in only one building stage.