This example combines stacked bar charts and a step-after line graph to compare gas and electrical emissions (kgCO2) with normalized costs across properties. It uses D3 v3 with SVG rendering, reading data from a TSV file. The chart employs ordinal and linear scales, dual y-axes, and d3.svg.axis for ticks, while d3.svg.line defines the cost line with interpolation. Legend rectangles and value labels clarify the two categories.