While adding solar panels to rooftops will help, recent research reveals an even more effective way for Japan to slash emissions from homes and offices. Better heat insulation is now seen as the key in clamping down on CO2 from one of Japan’s top energy-consuming sectors.

This “discovery” may seem odd given how widespread heat insulation measures are around the world. However, house construction in Japan has its own particular history, and to date government efforts to promote building energy efficiency have been weak and unsuccessful.

Last year’s decarbonization pledge changed the mood and budgetary allocations have followed. This summer, the infrastructure ministry (MLIT) committed ¥1.38 billion ($12.5 billion) to a program specifically tied to energy efficiency of homes and buildings, with related initiatives also launched by the METI and the MoE.

The new injection of funds is expected to revive and, this time, deliver results from two programs: Zero Energy Buildings (ZEB), and Zero Energy Houses (ZEH). If successful, electricity demand in a sector that currently makes up a third of national consumption, could decrease drastically.

Why decarbonize buildings?

The business/manufacturing sector represents the largest share of Japan’s final energy consumption, accounting for 63% in FY2019. Of this, 16.6% comes from office buildings, ….