Illumination and conservation: a case study evaluation of daylight exposure for an artwork displayed in an historic building

This paper describes the application of climate-based daylight modelling to predict the annual daylight exposure received by an 18th century painting oil displayed on the Stone Staircase at Mount Stewart, near Belfast, Northern Ireland. The simulation predicted that the painting was receiving several times the recommended daylight exposure limit of 0.6 Mlux hrs for this type of artefact. The predictions were compared against the limited monitored data that were taken at the site. Notwithstanding the shortcomings of the monitored data, the agreement with simulation was sufficiently encouraging to allow recommendations to be made regarding interventions to help reduce the daylight exposure experienced by the painting.