Housing conditions and energy efficiency Households according to whether they have made improvements to thermal insulation or the heating system, by degree of urbanization. Unidades: Horizontal percentages. ,Has made improvements to thermal insulation or the heating system,No improvements have been made and it is warm enough during the cold months,No improvements have been made and it is not warm enough during the cold months, Total,14,1,60,8,25,1, Densely populated area,15,60,25, Intermediately populated area,12,5,61,1,26,3, Scarcely populated area,14,4,62,9,22,7, Notas: Fuente: Instituto Nacional de Estadística