Phase 1
What Rough-In Means for Solar
Solar rough-in happens on the same schedule as your electrician’s rough-in: after framing, before insulation and drywall close up the walls. We install a capped roof penetration sleeve at least 1¼ inches in diameter on the solar-ready portion of the roof, run conduit or an approved pathway from that sleeve down to the electrical panel location, and confirm your panel has reserved space for a labeled “For Future Solar Electric” breaker. None of it is visible once drywall goes up, which is exactly the point.
Phase 2
What Trim-Out Means for Solar
Trim happens once the roof and siding are finished and the panel is accessible again, typically near the end of the build or, on a repeatable program, shortly after closing. We mount the racking and panels, land the conduit run at the reserved breaker space, install the inverter and any battery, and schedule the final electrical inspection and utility interconnection so the system can be energized.
Code Requirements
WSEC Solar-Ready Rough-In Requirements at a Glance
The 2021 WSEC Appendix RB solar-ready provisions spell out exactly what has to happen at rough-in on qualifying new homes, whether or not solar goes in at closing.
Qualifying Roof Area
Applies to homes with at least 600 sq ft of roof area oriented between 110° and 270° of true north.
Solar-Ready Zone
At least 300 sq ft (150 sq ft for smaller townhouses) of unobstructed, low-slope roof reserved for future panels.
Roof Penetration Sleeve
A capped sleeve, minimum 1¼-inch inside diameter, installed adjacent to the solar-ready zone.
Reserved Panel Space
A dual-pole breaker space reserved and labeled “For Future Solar Electric” in the main service panel.
Why Sequencing Matters
Rough-In Mistakes Get Expensive at Trim
A missed conduit run or an undersized penetration sleeve is a five-minute fix during framing. After drywall, paint, and siding are done, it’s a rework ticket that touches multiple trades and pushes your closing date. We coordinate rough-in timing directly with your electrician and framing schedule (not as an afterthought), so the trim crew shows up to a job that’s ready to go, not a job that needs troubleshooting first.
Beyond Rough-In & Trim
The Rest of Your Solar Build Process
WSEC Energy Credits
See how solar compares to other WSEC compliance options on cost per credit.
Homebuilders Hub
Fixed pricing, trade coordination, and battery upsell options across Western Washington.
Common Questions
Rough-In & Trim FAQ
Do we need solar rough-in even if the buyer isn’t installing panels at closing?+
If your home qualifies under WSEC Appendix RB (600+ sq ft of correctly oriented roof), yes: the solar-ready zone, penetration sleeve, and reserved panel space are code requirements regardless of whether solar is installed at closing. Rough-in now means panels can be added later without opening up finished walls.
How much time does rough-in add to the framing schedule?+
Typically under an hour per home when it’s coordinated with your electrician’s existing rough-in visit. It’s the coordination, not the labor, that determines whether it adds time, which is why we schedule directly against your framing calendar rather than as a separate site visit.
Who’s responsible if the rough-in doesn’t match the trim-out plan?+
We spec the rough-in against the final system design up front, so trim-out is a completion of the same plan, not a new one. If Solphos handles both phases, that mismatch simply doesn’t happen.
Can trim-out happen after the home closes?+
Yes. As long as rough-in was done correctly, trim-out can happen before closing or after, on the buyer’s timeline. The reserved sleeve and panel space mean there’s no wall or siding work involved at that point.
Sources: 2021 WSEC Appendix RB: Solar-Ready Provisions · Seattle SDCI Tip 422: Renewable Energy and Solar
