You depend on your target group for reaching your aim of saving energy, so you need to find a reason for them to participate. This is easiest by designing your project to meet your target group's needs. We call this a 'bottom-up' approach. Examples of bottom-up projects are Social Housing Energy Efficiency Renovation (based on the needs of fuel-poor residents) and Energy Expert (based on tenant's initiatives).
But your target group's needs may not all connect to your agenda: they might want advice on garden planning rather than on saving energy. Or funding bodies may expect that you follow your plans carefully. So you might have limited flexibility, and have to apply a more 'top-down' approach (see the Off. Really Off? project for a good example).
Both alternatives have their pros and cons. In practice, the choice is usually not 'either-or': you need to strike a balance. You can also try to select a target group with interests that align with yours.
Further resources on models of behaviour change.