Electricity consumption in buildings is highly variable on time scales of seasons, hours, minutes, and even seconds. Yet, energy performance in building sustainability standards and rating systems is typically assessed in terms of total annual energy use, cost, and/or GHG emissions. Given that in North America buildings.account for between 45 and 75% (depending on the region) of total electricity consumed, it is relevant to define an assessment framework to quantify the impact of variability in building electricity demand on the electricity system. This study proposes "Grid Compensation Scores" (GCS) that assess the contribution of a building electricity demand profile to increasing or decreasing the variability in the system electricity demand profile. The GCS are applied to two building types (single family house and office building), located in two-different electricity systems (Alberta and Ontario), and with a variety of building energy technologies (building variants). Results show significant differences in the GCS of different technologies depending on the building type, the electricity system, and the time scale (seasonal vs. daily). The grid compensation scores provide a quantitative assessment of the impact of building variants on the electricity grid at different time scales, which allow for a systematic comparison among building variants. The results demonstrate that annual metrics can hinder decision making by obscuring variability that can alter the competitiveness of different building energy technologies. A multi-metric approach is therefore recommended for future assessments.