Need help estimating time to set up a program

I have started talking to my city about having me set up a city-scale weatherization program as a contractor.  I'm about to put together a more formal proposal, and need to estimate the number of hours it would take to secure a grant.  I realize it's impossible to know for sure, but does anyone have any suggestions for how to estimate this?  My sense is that I would need to do preliminary relationship building in order to name the partners that the program would include...this would have to be spelled out for the grant.  

Can anyone share their experience with this?  Even better, if someone has a proposal like this that they can share with me as an example, that would be very helpful!

Thanks in advance for any help or ideas you can share...