Do you have a realtor(s) promoting your properties? Are you promoting your project on line?
What are the demographics of your buyers? Create a marketing plan to target those specific buyers.
How about collaborating with the other development to promote the improving neighborhood ... the theme would be "transitioning" into ...???
What are the current functions/purposes of those surrounding old buidings? Contact non-profit housing agencies / community development groups and partner with them to beautify the neighborhood. Convert those buildings into community facilities.... more