Natural ventilation, relying on openings in the facade, is applicable to a limited range of climates, sites and building types. Advanced naturally ventilated buildings, such as those using stacks to encourage buoyancy driven airflow, or hybrid buildings, which integrate both natural and mechanical systems, can extend the range of buildings and climate within which natural ventilation might be used. This paper describes the design of a new library building for a college, located near Chicago, which uses a new hybrid ventilation concept despite the severe continental climate. The likely operation of the building is illustrated using dynamic thermal modelling and computational fluid dynamics analyses. The new building challenges ingrained preconceptions about building designs for severe climates and exposes barriers to low energy buildings posed by national standards and guidelines. (C) 2006 Elsevier B.V. All rights reserved.