The hygrothermal performance of building envelopes varies based on the temperature and moisture content of their materials. However, multiple building codes adopt constant conductivity values for construction materials based on standardised conditions that do not represent real operating conditions. Currently, a new procedure allows for correcting these normative conductivity values with a limited calculation effort, taking into account the characteristic environmental conditions of each location. This article combines climate records compiled at 313 weather stations distributed in North-Eastern Spain and uses this method to determine the applicable correction factors for materials of masonry facades. The exhaustive characterisation of this geographic area allows for creating correction isopleth maps that may be functionally integrated into building codes to improve the thermal design of buildings at any site of the territory. The results indicate a lower need to correct in mountainous areas, while the Mediterranean coast and the Ebro river valley exhibit larger deviations from normative values with respect to the actual conductivity of the materials. These corrections have been validated in two important cities in this area, Barcelona and Zaragoza. (c) 2015 Elsevier B.V. All rights reserved.