An indium-based seal augmented with an adhesive, developed to maintain a vacuum between two sheets of glass, avoids the high temperatures required to produce a seal in evacuated glazings to date. An experimentally-validated three-dimensional transient model has been used to predict heat transfer for an indium/adhesive sealed 1 m(2) area evacuated window with a highly insulating frame. An overall heat loss coefficient of 0.9 W m(-1) K-1, with a midplane value of 0.36 W m(-2) K-1, can be achieved with 0.72 visible transmittance for two 6 mm panes separated by 0.2 mm diameter pillars 40 mm apart. The conduction through a 3 mm edge-seal was 1.14 W m(-2) K-1. Detailed three-dimensional isothermal contour plots through the system are presented.