It would be very useful if while creating a toposurface we could snap the points not only to the coordinates but to the elevations of existing building components. For example, if we could snap the points of the toposurface to the base of building footings it would be a lot easier than exiting the edit mode to check the elevation and then re-entering to place a point at that elevation. This would make creating a toposurface that follows the underside of existing building components much quicker and simpler, for example during a cut and fill exercise.
