The built environment has been assessed as accounting for 70% of electricity consumption in the USA (Claire 2007) and globally, the built environment accounts for 40% of energy consumption (Kolokotsa et. al. 2009). While New Zealand generates most of its electricity from renewable hydro electric sources, there are limited opportunities to expand such generation. As a result, the NZ government has been promoting energy efficiency as a means to reduce growth in electricity demand, with the focus to date on the residential sector. Efficiency policies relating to office buildings have recently been proposed, but little prior research has been carried out on this sector in NZ. This research identifies trends in office building electricity consumption over the period 1990-2008 using data from the Property Council of New Zealand annual survey of building operating expenses. This will help establish a base line against which future energy efficiency initiatives can be assessed. Findings include relatively stable electricity consumption rates over the study period but a surprising decline in real electricity prices for this sector until 2004 followed by sharp increases since.