Costs associated with the permitting, inspection, and interconnection processes can be reduced through streamlining and standardizing requirements and application formats across authorities having jurisdiction (AHJ) and utilities, as well as training code officials and system-installer employees. Opportunity cost is also important to nonhardware costs as fixes and reworks will be mitigated as a direct result of a well-educated workforce. Training on codes and standards improves the pass, fail, and rework metrics of PV systems.

Sandia provides technical assistance and information on PV codes, permitting, inspection, and interconnection. National laboratory expertise in the areas of utility interconnection and PV building code/permitting and installation requirements will augment the array of expertise available through DOE’s external partners and ensure the most up-to-date information is included in their materials. A major role for Sandia is in the structural and building permitting.


Wind loads, live loads, snow loads, and drift loads are loads to be considered as well as other loads (such as seismic in certain circumstances). Furthermore, loads are to be considered in combination as defined by ASCE 7-10. This effort will educate the solar community through workshops and similar formats on how to properly assess the capability of a structure, and also simplify it to the point where a non-structural engineer can apply it. The information gathered from Sandia’s structural analyses will be applied in a brief and useable format to produce a consistent expedited permit process that includes the correct consideration of structural issues.

  • Contributions to code official training modules
  • Policy influences on PV system practices and code enactment such as ASCE code making

The applications of codes across the United States are variable and inconsistent. This inconsistency has significantly increased the ‘soft’ cost of solar installations and disallowed an enormous number of potential solar installations. The need exists to not only standardize the process, but make it solar specific.

A “Structural Guide for Solar Installations” will be drafted to bring continuity on a national basis to structural load determination to provide the tools and guidelines for the installer to help ensure that solar systems are properly specified and installed. The guide will also offer revised direction to address national codes based on empirical data to be produced. A test plan will be prepared in FY12 for testing to be completed in FY13. The resulting data will facilitate reduced permitting and installations costs by

  1. increasing the number of installations;
  2. optimizing the structural solar installation;
  3. reducing the permit application time & associated cost; and
  4. potentially eliminating the need for a structural engineer.

A test plan will define the number and types of tests to physically quantify the actual strength of roof systems and directly compare them with calculated carrying capacities based on ASCE7-10 and current engineering methods. This will allow a direct comparison with the actual conservatism in current practice and provide empirical data to overcome it. Both the wood framing and the roof deck will be well characterized, so that we will be able to predict nominal strength using current design codes, such as the National Design Specification for Wood [NDS], the International Residential Code [IRC], and the International Building Code [IBC].