This paper describes the application results of a previous and current EU-project on super insulating glazing based on monolithic silica aerogel. Prototypes measuring approx. 55 x 55 cm(2) have been made with 15 mm evacuated aerogel between two layers of low-iron glass. Anti-reflective treatment of the glass and a heat-treatment of the aerogel increases the visible quality and the solar energy transmittance. A low-conductive rim seal solution with the required vacuum barrier properties has been developed along with a reliable assembly and evacuation process. The prototypes have a centre heat loss coefficient below 0.7 W/m(2) K and a solar transmittance of 76%. (C) 2005 Elsevier B.V. All rights reserved.