Is it possible to increase thermal isolation thickness to achieve even better isolation?

Obviously it is possible to increase thermal isolation thickness, obtaining U ratio values below 0.15 W per sq.m., i.e., at the level of passive partitions. One should however consider other significant parameters other than thermal conductivity such as the building’s air-tightness, structure shape, window size etc. Therefore, from an economic point of view it is the most beneficial to well isolate the house while taking into account the relationship between costs and benefits.