[litany]

That is how title 24 has operated for years. They have two methods for compliance, prescriptive and engineered. The prescriptive method is they specify minimum Efficiency values for things like insulation, doors, windows, HVAC, water heater, etc and takes climate zone into consideration. The engineered gives you an annual energy budget and you just have to meet that in the model. So for instance you can have a house that doesn’t have insulation but with enough solar on the roof you can make up for it. The idea is prescriptive is to make it easier on owner builders and engineered is so that professional builders can optimize with market forces in consideration and designers can make trade offs like spending more money on efficiency in order to allow larger openings (doors and windows) as a percentage of total area.

This solar requirement has been a long time coming. I haven’t looked at the new standard, it’s called Title 24 2019 because it’s still under development but they might just pushing the energy budget low enough that solar is effectively required. Otherwise it may be required for prescriptive title 24 compliance. The article talks about square footage and 2kW minimum systems which to me sounds like the prescriptive requirement.

Personally I’ve never been able to use prescriptive for design reasons but some contractors for sure do, and they don’t understand the concept of modeling.

So yeah, you can innovate all you want and CA set it up that way for years now.

[Bjartr]

If it was this[1] proposal that was accepted, it applies to the performance path too.

[1] http://docketpublic.energy.ca.gov/PublicDocuments/17-BSTD-01...