During the construction of buildings in regions with relatively low outdoor temperatures it is necessary to pay more attention to the issues of heat preservation and minimizing heat losses through external enclosing structures. The paper analyzes the main ways of heat loss minimization through translucent enclosing structures. It is revealed that it is more expedient to reduce heat loss through a window structure by using an effective double-glazed window. The main methods of increasing the reduced resistance to heat transfer of a double-glazed window are described. The methods of reducing heat transfer which occurs due to convection and radiation are analyzed. The reasons for the need for the use of energy-efficient double-glazed windows are given.