A design is IP... a list is public domain. Ed
The builders design is specified in his "specifications".... So by default, the specifications are his design... Otherwise why would the other builder be wanting them...
By all means tell the Builder what components you want, but in terms of forwarding a detailed specification that another builder has produced.... I would be vary wary... Especially in this environment where builders are slowing down, if they see there jobs being sold to another builder, they will follow it through with litigation...
Get a quote from each builder, and then you need to compare apples for apples...
Ed, let's turn it back to your case... If you are using a specific type of sealant in your windows, which you have developed over years of testing, as a special mix of 4 different polymers and additives... Then would you consider this as IP... Although it is only a list of materials!!!!