New Research

Electric Power Consumption by Office Tenants (December 2014)
2014 annual average was 38.4 kWh/tsubo, down by 3.0% year-on-year

Xymax Real Estate Institute has been studying the volume of electric power consumed by tenants in office buildings in Japan and releasing the results on regular basis since June 2013. This is an update report covering the data up to December 2014.

Definition of Electric Power Consumption by Office Tenants

The electric power per tsubo (3.3 sqm) consumed by tenants in office buildings per month.

Key Findings

The areas covered by Tokyo Electric Power Company (TEPCO)

  • ・Electric power consumption was 35.0 kWh/tsubo in the autumn of 2014 (Oct-Dec), decreased by 1.1kWh/tsubo or 3.0% from 36.1 kWh/tsubo of the same period last year.
  • ・Annual average in 2014 was 38.4 kWh/tsubo also decreased by 1.2 kWh/tsubo or 3.0% from 39.6 kWh/tsubo of 2013.


Period January 2010 – December 2014 (monthly data)
Subject Data Of the office-use tenants occupying the office buildings in Japan under management by Xymax Group, the valid data (approximately 300 buildings and 3,000 tenants) was used in this study.
Calculation Method
  • 1) Calculate the monthly electric power consumption by tenant in kilowatt-hour (kWh).
  • 2) Adjust the outcome in 1 based on the ordinary business days of the week (excluding Saturdays, Sundays, and national holidays).
  • 3) Calculate the electric power consumption per tsubo (approx. 3.3 sqm) by dividing the outcome in 2 by the tenant’s rentable area (tsubo).
  • 4) Average the outcome in 3 by the areas covered by each electric power company.
  • ・Tenants that use the space for other purposes such as retail, warehouse and computer room are excluded from the subject data.
  • ・Tenants in buildings with central air conditioning or gas heat pump, where separate calculation of the energy use by tenant is impossible, are excluded from the subject data.
  • ・The month represents the month the electric power meter is read, usually on 20th of each month.
  • ・Extraordinary amounts (too high, too low) are identified as outlier and excluded from the subject data.
  • ・The number of subject tenants varies month by month as tenants move in and out.
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