Agree you have to do your homework and yes it does depend on price point and/or package options selected with each builder, but also where you're looking to build as there may be bespoke & custom builders who specialize in some neighborhoods, but not others, and who may offer or be willing to discuss more options. They typically have more flexibility to consider and add newly evolving energy efficiencies into their build/pricing. The bigger names generally have good efficiency spec packages on offer but will be more general spec with less/zero flexibility to upgrade further.
To be honest, all the home builders that I've worked with have great energy efficiency. I think it also depends on what appliances are being used in the homes as well.
High performance and ENERGY STAR® homes are homes that use less energy than one built only to the Texas residential building code, providing homeowners with a more comfortable home that operates for less money. An independent third party home energy rater tests every home in this program to help ensure that it meets strict energy efficiency specifications, which result in lower utility bills and a cleaner environment. On average, each high efficiency home is rated 18% above code, translating to a yearly electric bill reduction between $200-500.
The following denotes home builders who have made a commitment to building 100% of their homes to ENERGY STAR performance guidelines: Beazer Homes KB Homes Design Tech Homes Meritage Homes Ashton Woods D.R. Horton David Weekly Perry Homes
You have to really do your homework. Some builders have horrible energy efficiency in homes that cost under 250k but does fabulous on energy efficiency in homes priced over. Always take the energy package when buying new construction. It will pay for itself very quickly. Each builder should have a list of what features are included in their homes. Just check out the website for more information.