Bundled Versus Unbundled Approach

Does anyone have evidence of what works better in encouraging environmental behaviour change of households - a bundled approach (where the household receives information about a range of issues, such as energy, water, waste and transport) versus a single issue approach (where the household receives information about one of those issues at a time)? My gut tells me that the bundled approach should be better because it offers a wider range of engagement, but I'd like to see some evidence.

thanks,
David Meiklejohn