This is the 3723rd most frequent Russian word.
утеплению
"Утеплению" means "insulation" or "the process of warming/insulating."
In this sentence, "утеплению" is used in the context of construction, where it refers to the process of increasing thermal insulation.
Строительные работы по утеплению фасадов продолжались весь месяц.
Construction work on the insulation of facades continued all month.
Here, "утепления" relates to the method or process of insulating a house to improve its thermal efficiency.
Секрет успешного утепления дома — правильный выбор материалов.
The secret to successful home insulation is the right choice of materials.
"Утеплению" in this case implies the act of improving thermal insulation for public buildings.