Using both measured and modelling data, the hygrothermal environment in a national gallery was examined to envisage the buildings response to weather conditions, occupancy and HVAC operations. The measured data were acquired from the BMS system and purposely fitted monitoring instruments. The data was also used to validate a specially developed dynamic thermal model, which was then used in a series of simulations in a parametric study. The simulations ran under nine designed cases to test a number of low energy solutions proposed in a gallery renovation project, namely upgrading skylights, adding roof insulation, and applying an adaptable environmental control strategy. Through this systematic analysis and quantitative comparisons this study intends to provide reliable information for decision making for the renovation work to ensure an optimal solution and best results. This study was benefited by a close collaboration between the physicist, computer modeller, building manager and gallery conservationist. (C) 2013 Elsevier B.V. All rights reserved.