In 1840 Daniel Gooch, the locomotive superintendent of the Great Western Railway wrote to Isambard Kingdom Brunel recommending Swindon as the location for a much needed engine works. Just four years later, the GWR Central Engine Station was a reality. Having ceased operating as an Engine Station, it was acquired by English Heritage in 1992 to house the organisation's extensive archives. The 1992 interior refurbishment works to this Grade II* Listed building Selectaglaze treated windows on the south elevation to improve noise insulation from the railway lines. More recently the building required further renovation and conversion works which included the requirement for: "The thermal upgrading of windows by installation of secondary glazing units and draught proofing of windows" to specifications prepared by Oxley Conservation. A total of 100 sash windows of different sizes were treated using the slim profile Series 20 system for smaller windows and the heavy duty Series 90 range for "monumental" style sash windows, some with curved heads. Low emissivity glass was incorporated throughout to optimise the thermal performance.