Superficial condensation phenomena often occur on the glazed elements of buildings. As a result, the aim of this study is to put forward an experimental approach to assess the condensation rate on building glazing surface for full-scale room tests under realistic conditions. The proposed method for condensation quantification is applied in this work for surface condensation on a cold glazing (2.90 m × 2.30 m) within a ventilated test room (6.20 m × 3.10 m x 2.50 m). We first describe the full-scale test cell, focusing then on the experimental apparatus employed for the condensation study. This is followed by the description of the methodology for the condensation rate quantification. The approach is based on image processing techniques, using condensation pictures. This allows also to reveal the mechanisms behind the condensation appearance and growth. On the other hand, the experimental data achieved by this method are compared with theoretical results based on condensation rate and heat transfer coefficient correlations available in the literature. An overall difference of up to 18% between the measured results and the theoretical results was found for the condensation rate. Consequently, the method proposed in this work leads to promising results concerning the condensation rate quantification on cold glazing within full-scale enclosures.