Questions & Answers from Solar Permitting Made Simple, Safe & Effective
Responses provided by Gary Nordeen, WSU Energy Program, Mia Devine, NWSEED, Paul Andersson, City of Bellevue, Patti Miller-Crowley, Department of Commerce and Linda Irvine, NWSEED
Q: There is a structural engineer in a jurisdiction in my area who insists that houses built with trusses automatically need structural review by an engineer or the truss manufacturer and that it is necessary to know the species and grade of rafters. Can you address these concerns?
A: Residential systems are light weight (typical of the weight of a composition re-roof-- less than 4lbs/sf) and shouldn’t have any impact on trussed roof loading. They should not need structural review.
Q: What are other jurisdictions using as their flat permitting fee to cover just admin costs for permit processing?
A: It varies but in general jurisdictions should plan for flat fee to cover admin fee for processing and site visit (similar to what many jurisdictions charge for re-roof permit). Bellevue’s standard fee is $312 per residential PV system and Edmonds’ fee is $135 for the building permit (electrical permit not included). Hillsboro, OR (home of Solar World manufacturer) waives the building permit fee entirely to encourage more solar in their jurisdiction. A webinar participant offered that Thurston County charges a $400.00 flat fire code fee for the permit.
Q: What about standardizing utility interconnection agreements?
A: The interconnection workgroup has been working on this issue. At this point the utility interconnection best practices work group has decided that due to variations in legal requirements with different utilities, they are not going to focus so much on a standard application as a list of best practices and a data template. The workgroup is collecting the same data from each utility and we should see their results in early 2015 (will be posted on the NW Solar Communities website).
Q: What training and / or certification is being developed / required for individuals installing the support system for roof-mounted solar panels? Comments on installing supports directly to the standing seam of a roof covering seems a contradiction to code section M2302.2.1(5)?
A: WSU Energy Program provides new rule training, done several times a year. They do not train on how to attach racking – that’s up to the installer. While there is no required training for solar installers, there are national certification programs, such as the North American Board of Certified Entergy Professionals (NABCEP) solar installer’s certification. It is up to the consumer to do due diligence on the installer’s qualifications.
Q: How did Bellevue determine their flat fee?
A: Bellevue’s Over The Counter permit fees are based on estimated time for processing and inspection (approximately 2 hours). Non-OTC permits are based on value of installation.
Q: What about when the building is required to be re-roofed, does the system require disassembly and permits for the solar equipment?
A: Installers recommend that if the roof has less than 10 years left it is best to change out the roof before going solar. However, it is feasible to remove, reroof, and reinstall. The contractor will generally make recommendations about this as a result of their inspection. Typically, it wouldn’t require a building permit just to remove and reinstall an array.
Q: Realizing all homeowner associations are not the same, generally though, is there much pushback from HOAs regarding the panels and where they can be placed?
The planning group has put together an issue paper with a template resolution for HOAs and reasonable guidelines addressing aesthetics without compromising solar array effectiveness. It and other planning tools can be found on the NW Solar Communities website. State law does not let HOAs prohibit arrays. This issue came up several times in Bellevue’s recent Solarize campaign but they were able to successfully resolve issues with HOAs every time.
Post webinar note: We are trying to expand out outreach to Homeowner Associations about this guidance. If you have an email list for associations in your area or have suggestions for efficient statewide outreach to HOAs, please contact .
Q: We have received permit applications to add roof top solar systems onto accessory post-framed structures that were designed to support a very low roof load, often dead load 3 psf or less, with purlins spanning between trusses typically 12-ft apart. Would the panel address placement of the solar system on the roof of post-framed structures?
A: If one came across this situation (i.e., knew a building was designed for a load of less than 3 psf) tell applicant it needs an engineer sign-off to ensure structure could safely support the array.
Q: What is the average cost of a residential system?
A: Washington’s average system (5 kw) averages in the $20,000-30,000 range, dependent upon what type of roof it is attached to and a number of other factors.
Q: In our city we deal with too many evergreen & other trees. Where are there regulations to prevent future shading of solar access?
A: There are no protections unless a city has adopted solar easement protection measures or other vegetative restrictions in code. Solar may or may not always work and one should remember that trees will grow. Community solar arrays can provide residents with a positive alternative if they have unsuitable locations.
Post webinar note: Solar Energy in Comprehensive Plans provides examples where local governments provide for solar access and balance solar with competing policy interests (including trees).
Q: If panels are installed on a flat roof, with little extra tilt, what percentage of effectiveness is lost at this angle of exposure, compared to an ideal angle of tilt?
A: One needs exact numbers– but it is only a “small percentage” of energy lost. Part of an installer’s toolkit is to determine this for conditions at a specific roof. The tilt may also be part of maximizing summer production vs sacrificing winter production. In Washington’s short winter days it may be fine to forego part or all of winter production in order to maximize summer production. Of greater concern is snow load if you go too flat. Note: Webinar participant offered that Kittitas County has created a policy that can exempt many residential solar arrays from an engineering requirement. We are in a high snow load area and may require engineering for some arrays due to this factor.
Q: Who issued the "Solarize Bellevue" grant? Any idea if more are available for smaller jurisdictions?
NW Solar Communities did a competitive solicitation in both Washington and Oregon. We issued 7 grants from small, rural areas to Bellevue and Mercer Island at the larger end. NWSC is asking DOE for Phase II funding approval, and assuming they get approved, their intent to have another round of “mini-grants” funding/seeding for a variety of things including Solarize campaigns.
Questions remaining after webinar time ran out:
Q: In the solar permitting packet, the checklist indicates you must provide a site plan. What is the purpose of the site plan? Site plans are sometimes difficult for the homeowner to create, and if this meant to be an easy, simple way to get a permit, why ask for the site plan?
A: Thanks for this feedback. As a result, we are looking at whether this is needed and if the checklist should be modified to either remove this item or at least identify that it is optional based on jurisdictional needs. While it would be useful for free-standing ground mounted arrays to prevent intrusion into setback areas, for roof mounted arrays it may be unnecessary.
Q: Where can we find that planning template for homeowner associations?
A. It is on the Planning & Zoning webpage of the NW Solar Communities website.
Q: What sort of energy savings are being calculated for individual installations?
A: Energy production will vary depending on latitude, module orientation and tilt, shading, inverter efficiency and other factors. As a rule of thumb, solar installations in Western Washington produce 1,000 kilowatt-hours per installed kilowatt on an annual basis. Solar installations in Eastern Washington produce about 1,300 kWh annually per installed kilowatt. For example, a typical 5 kW installation in Western WA would produce 5,000 kWh each year. System life is projected to be at least 25 years.
Q: What is the impact from the solar PV system on a home’s roof when it is time to re-roof? Have there been any studies done regarding the loss of generation due to clouding of the surface of the PV system? Similar to what happens to your headlights on your car.
A: Solar PV systems actually help preserve the life of the roof. When it is time to re-roof, the system can be temporarily removed and reinstalled. We are not aware of studies of PV surface clouding. NREL published a study of overall degradation rates here: http://www.nrel.gov/docs/fy12osti/51664.pdf
Q: I work with a development that requires new homes to be solar ready. Do you have a standard that defines "solar ready". I saw a standard for Energy Trust of Oregon, can't find one for Washington State. Building official had nothing. WSU didn't have a standard either.
A: It is not a standard, but the Planning Workgroup has developed an issue paper on Solar Ready Construction. The International Residential Code has a Solar Ready Appendix (15 IRC Appendix U: Solar-Ready Residences) that was developed on the national level.
Q: Will PowerPoint be posted on MRSC site?
A. Yes, it will also be linked from the NW Solar Communities website.
Q: How many square feet of PV panels are required to get a 5 Kw average size system for a single-family residence?
A: : A 5 kW system will requires about 400 square feet of PV panels.
Feedback/Informational: Building Code Council PV TAG is meeting this spring to review current Building Code language and the changes coming in the new 2015 Building Codes to be effective in 2016.
If you have additional questions, please email the question to and she will make sure to get it to the right person.