This paper presents the theoretical basis of the matrix method direct-applied to determine the heat losses of the building and harmonized with the requirements very urgent regulatory documents. Matrix method consists in drawing up a series of matrices with geometrical and thermal characteristics and their subsequent multiplication by the rules of linear algebra. Matrix method is the most accurate way to determine the transmission heat losses and, consequently, the required heating power, because linear and point thermal bridges attached in Annex E SP 50.13330.2012 ‘Thermal performance of the buildings’. The updated edition SNIP 23-02-2003 are taken into account. Tools of linear algebra allow to operate with a large data sets and take into account a number of different factors affecting the thermal balance of the building simultaneously. Matrix method is easily automated. Even the simplest tabular editors allow adapting them to write matrices and perform an operation of multiplication of matrices. In complex matrices using the opportunity to make up for the buildings detailed data array that is an information model of the thermal climate of the building is appeared. Approach realized by the matrix method corresponds the direction of development of science given at the federal level in Russian Federation – on energy saving and achieving maximal energy efficiency fully.
