Contacting the construction department about serviceability

About a year ago I talked to a representative and he stated some rural land I have was in the serviceability area for xfinity, but that I needed to contact the construction department when we were preparing to start construction on the property.  We are starting the process of building and I am unable to find a number for the construction department, but I need to find out how much it is going to cost to get service ran to our property and find out when it needs to be done during the building process.  How do I contact them?