Problem: raster analysis does not cover the spatial extent I want...

Some of you noticed that the spatial extent of the raster buffer (which is really just a recode of the cost distance surface) did not extend to the full extent of the parcels dataset (it actually stops at the extent of the hydrants dataset). There is a setting in Spatial Analyst that controls the spatial extent for subsequent operations. If you set this to the parcels dataset then the raster cost surface should extend to the full boundary of that dataset. Here is how you change the analysis extent in

From the Spatial Analyst menu select Options. Then click the Extent tab and change the Analysis extent to "parcelclip" (or whatever your parcels dataset is named).

Now when you generate the cost distance surface (using the hydrants as the source location) it will generate cell values covering the full extent of the parcels dataset. By default the Analysis extent is set to "Intersection of Inputs" and since the hydrants dataset was one of the inputs, the spatial extent of the hydrants dataset was constraining the area of the cost/distance surface.