The Palace of Westminster is facing a major restoration programme. In October 2012 a joint study group of House of Commons Commission and House of Lords Committee reported that the historic fabric was in a serious state of decay, and that the current ventilation system were outdated and in need of a complete replacement. This provides the unique opportunity to systematically re-examine the original Victorian stack ventilation system, which had been in use for 90 years before it was replaced with mechanical ventilation and air-conditioning in the 1950s. Previous research by the PI has shown that the historic system was highly sophisticated. Its design had been refined over several decades and followed principles similar to those used in modern naturally ventilated buildings to reduce energy use. It was designed to exploit, as far as possible, the natural stack effect produced by hot air ascending air shafts within the large towers and numerous gothic turrets of the Palace. Yet, how effective was this historic stack system and how far could it be revitalized to provide a sustainable solution to ventilation in the 21st century? To address this question it will be essential to develop a critical understanding of the historic system. Although various studies have highlighted the importance of the Palace within the wider history of environmental design, to date there is no comprehensive study of the original stack system. This project aims to fill this significant gap in the literature by providing the first in-depth investigation into the design, history and performance of the ventilation, based on a combination of archival research, surveys inside the Palace, and the analysis of historic data collected and scientific studies conducted between 1852 and the 1941. Moreover, it will investigate how it could be restored in conjunction with the restoration, exploiting its potential in providing a sustainable strategy. Surveys and archival research will be used to reconstruct the original technical arrangements adopted in mid-19th century, to retrace how scientists, working alongside architects and engineers, had developed them, and to explore how the system was modified over its lifetime. Records of historic experiments, eye-witness accounts and measured data the project will be used to explore how scientists had empirically evaluated the performance of the ventilation, e.g in terms of thermal comfort and air quality. Covering a period of 90 years, these records will also be used to undertake an in-depth analysis of how the ventilation had performed historically under a variety of conditions. The gain such insights, however, the project will not only cross different areas within the field of history(e.g. history of science, environmental and architectural history), but also draw on current scientific methods to review the historic evidence from a technical perspective. Over the past 3 years the PI has conducted a pilot study, funded by the Kent Institute for Advanced Studies in the Humanities, and built a partnership with the Palace of Westminster Restoration and Renewal Programme (R&R), a body appointed by the UK government to coordinate the restoration. Recognising the importance of the proposed research to the programme, the Houses of Parliament agreed to be project partner. The research will form a separate work stream within the programme, which will be led by the PI and feed directly into the restoration. In addition to taking part in project meetings at Westminster and the PI will lead a series of workshops and project conferences, bringing together the R&R team and Parliamentary Estate Directorate to develop proposals for re-vitalizing the stack ventilation based on the new insights yielded by the historical research. In addition to demonstrating how historical research can be used to gain insights into past environmental principles, the project aims to show how it can be applied in the context of conservation.