For developers in California, the prospect of building low-rise multifamily and single family residential buildings in 2020 can be challenging for one reason: photovoltaic systems are becoming effectively mandatory according to the California Energy Code starting January 1st, 2020. When we say “effectively” mandatory, this doesn’t mean there is a “mandatory requirement” as outlined in the Energy Code. It simply means that, with the upcoming code changes, installing photovoltaic panels will be unavoidable for the sake of code compliance whether your project takes the prescriptive or performance compliance approach.

The prescriptive approach to complying with state-mandated energy performance requirements demands that building owners follow a set of guidelines for direct compliance. Depending on the climate zone, your project will be subject to a certain set of standards pertaining to the building’s envelope and system features. If your building follows these standards to the letter, it will automatically comply with state standards. Starting in 2020, one of the prescriptive requirements will be photovoltaics. Under the prescriptive approach, your building will always be required to install a photovoltaic system of the prescribed size.

The performance approach is an alternative and generally more favorable compliance method. It is less rigid, allowing developers to either improve or reduce the efficiencies of their building envelope and systems by offering tradeoffs in their energy budget. Projects using the performance method must still show that the proposed Time-Dependent Valuation (TDV) energy is less than or equal to the standard design TDV. Additionally, your building’s solar Energy Design Rating (EDR) must be greater than or equal to your building’s Energy Design Rating. A building’s EDR score of 0 represents a net zero building. A score of 100 is equivalent to a home built to 2006 IECC code. A solar EDR is the combination of your building’s solar electric generation system and modeled energy consuming systems.

In order to have a solar EDR that is greater than or equal to your building’s EDR, you will have to design for solar or tie directly into community solar. More efficient buildings lower the building EDR. This will make the solar EDR easier to achieve by allowing for smaller solar systems, but ultimately the emphasis on solar is so great that it will be financially or physically infeasible to design against it.

In essence, the CEC has removed any possibility of avoiding solar installation on new low-rise multifamily and single family residential projects since the prescriptive and performance approaches both call for photovoltaic installation. In other words, the requirement for photovoltaic systems on these types of projects is effectively mandatory.

Luckily the payback period for these products is not nearly as long as some may think since the hard costs will be reduced over time, and for multifamily owners, the photovoltaic system can be tied into the main house meter to recoup costs and deliver strong ROI. So although it is effectively required for Title 24, there are plenty of incentives for complying with these measures.

VCA Green is well equipped with qualified CEAs who can assist you through this design hurdle. For more information on energy code compliance on your new or existing buildings, contact Moe Fakih below:

Moe Fakih, Principal


Contributing Writer: Burke Boydell, LEED AP Homes

Image source: Pixabay, labeled for reuse.