Industrial building rehabilitation is one the latest trends within the field of sustainable development. However, these interventions often disregard the issue of user comfort, despite being the most important factor of energy efficiency. This work deals with the assessment of the indoor thermal conditions of a restored industrial building, considering not only air temperature but also mean radiant interior temperature. The research focuses in the influence of the radiative performance of the saw tooth roof of this building regarding these conditions. Results show that the analysed thermal parameters depend directly on the roof thermal behaviour. In fact, the glazed area of this type of roof is responsible for the 60% of the increase of the mean radiant temperature over air temperature. This result is a consequence of the high interior temperature reached by the glass panels, 47°C max, despite their northern orientation. These temperatures are a result of the diffuse radiation action and, particularly, the heat flux emitted by the opaque part of the saw tooth-roof, which significantly reduces the radiative cooling capacity of the glazed surface.