Assuming you will accomplish the core goal of having some portion of the Smart and Secure offering made standard in every home your builder sells, the method by which you sell upgrades may vary from builder to builder. The two key factors that will drive selling methods will be the percentage of homes that are built on spec and whether the builder uses a design center.
Home builders that build a high percentage of homes on spec, will likely not have a design center. In this case, you may not gain access to the customer until post - close.
Home builders that build fewer homes on spec and allow the customer to select options will likely have a design center. Typically that is the best place for you to sell upgrades.
Lastly, figure out when you will install the product. If you are dealing with a spec builder or you have deferred structured wiring to the electrician, you may be tempted to install and sell post-close.
Be very careful recommending this approach. Your communication with the home builder must be very very good and you must gain access to the homeowner prior to close via email or phone or both. If you don't, you will be fighting the door-to-door sales squads from Vivent, ADT, Guardian and others. It is almost certain you will lose sales to these companies deferring installation to post close.