The calculation of thermal resistance and thermal transmittance is based on the composition of the envelope and thermal properties of the used materials and is performed in accordance to standard EN ISO 6946:2017: Building components and building elements - Thermal resistance and thermal transimttance - Calculation methods.
Determination of dynamic thermal performance of the specific parts of the building envelope is using a simplified one-dimensional calculation method. The goal is to assess the decremental factor and the time shift of the temperature amplitude between its inner and outer components according to standard EN ISO 13786:2017: Thermal performance of buidling components - Dynamic thermal characteristics - Calculation methods.
Measurements of airtightness of building products and elements is performed in accordance to standard SIST EN 12114:2001. Measurements of air low rate through specimen at various static pressure differences, both positive and negative, between specimen faces (sides) which allow for determination of air permeability characteristics of the specimen. Air permeability characteristics may be used for the purpose of estimation of air leakages/infiltration through building envelope.
Long-term measurement in Passys cell incorporates four construction walls that are exposed to actual outdoor weather conditions and dynamic thermal properties like delays of heat fluxes and temperature peaks. Measurements are performed in different wall layers according to ISO 9869-1:2014, and the results are analyzed.