What resale value premium can I expect from installing rooftop solar?

Dahlia, your skepticism is correct, and it is more correct in Boise in 2026 than almost anywhere else in the country. That 4 to 6 percent figure comes from research conducted when homeowners got a 30 percent federal credit and full retail net metering. In Idaho today you get neither. Run your own numbers against that range. Four percent of $600,000 is $24,000. Six percent is $36,000. You are being told a $32,000 to $35,000 system returns roughly what it costs. Here is why that does not hold. The federal credit is gone. The One Big Beautiful Bill Act, signed July 4, 2025, terminated the Section 25D Residential Clean Energy Credit for anything placed in service on or after January 1, 2026. On a 2025 install your system would have carried a credit of $9,600 to $10,500. In 2026 it carries zero. That is not a small adjustment to the payback math, it is the largest single input. Idaho's replacement is much smaller than people assume. The state Residential Alternative Energy Device Deduction gives you 40 percent of cost in year one and 20 percent for each of the next three years, capped at $5,000 a year and $20,000 total. On a $35,000 system you hit the cap every year, so you get the full $20,000 deduction. Idaho's flat income tax rate is 5.3 percent for 2026. That deduction is worth about $1,060 in actual tax, spread over four years. It is a deduction, not a credit, and the difference matters enormously here. Now the part that specifically hurts a Boise appraisal. Idaho has the cheapest residential electricity in the United States, 12.35 cents per kilowatt hour as of May 2026 against a national average of 18.44 cents. A solar premium is fundamentally a capitalized savings number, so the cheaper your power is, the less your array is worth to the next buyer. Every study that produced a 4 to 6 percent premium drew heavily on high-rate states. On top of that, Idaho Power closed legacy net metering to new systems on December 20, 2019. Systems installed after that date go on net billing, where exports earn an export credit rather than a retail offset, and Idaho cut that compensation by roughly 31 percent again in late 2025. The credit is currently in the neighborhood of four cents a kilowatt hour, and you should confirm the live schedule directly with Idaho Power before you sign anything, because it gets reset. There is a real quirk worth knowing here. The Idaho PUC ruled that grandfathered net metering attaches to the system site, not to the customer, so a house with a pre-2019 array carries a genuinely transferable benefit through 2045. Your system will not have that. In practical terms the Boise resale premium for solar is split into two tiers by tariff vintage, and a new install lands in the lower one. Two more things on the appraisal side. Your instinct to own it outright is exactly right. Fannie Mae Selling Guide B2-3-04 lets an appraiser include an owned system in the appraised value when ownership is documented, and requires leased and power purchase agreement systems to be excluded entirely as personal property. If you finance it, make sure the lender does not place a UCC-1 fixture filing against the property, or your future buyer's lender will have to clear it to close in first lien position. And notice the trap in 2026. The only federal money left in residential solar is Section 48E, good through 2027, and it is claimed by the third-party owner on leases, power purchase agreements and prepaid deals. That is precisely the ownership structure that Fannie Mae requires an appraiser to exclude from value. So this year, the subsidy and the resale premium are mutually exclusive. You can have one or the other. Eren's point about roof life is the right one and I would make it a hard rule rather than a suggestion. Do not put a 25 year array on a roof with 10 years left in it. My honest bottom line. If you are installing for the resale premium, the 2026 math in Idaho is the worst it has been in over a decade, and I would not spend $35,000 chasing a $24,000 to $36,000 number that was measured under conditions that no longer exist. If you are installing because you intend to stay 12 or more years, want the power, and value the hedge against future rate increases, that is a defensible decision that happens to also help a little at resale. Those are two different purchases and the second one is the honest one. One practical step. Before you commit, ask the installer to run PV Value, the discounted cash flow tool built with Sandia National Laboratories that green-certified appraisers actually use, with Idaho's real retail rate and the current export credit plugged in. Make them show you the output. If they will not, that tells you something too. I am a real estate professional and not a CPA or a tax attorney, so run the Idaho deduction past your own preparer before you count on it. I am Zoltan Peresztegi and I work the South Bay and greater Los Angeles market, where the electricity math is close to the opposite of yours, so I will not pretend to know Boise appraisers. If you would like an introduction to a strong Treasure Valley agent who can tell you what solar actually did to nearby sales in your price band, say the word and I will find you one. Zoltan

Dahlia, there is no standard answer to this question as it is heavily dependent on your local market. Nationally it tends to be ~ 3% of the sales price. Keith Jean-Pierre Managing Principal The Dapper Agents Real Estate Operations in ALL 50 States

You will need a proof for that. 3 Action Steps to Protect Solar Resale Value Require the Appraiser to Use the AI "Green Addendum": When selling, your listing agent must explicitly demand an appraiser certified in green valuation or attach the Appraisal Institute Form 820.06 (Residential Green and Energy Efficient Addendum) to the lender packet. Without this standardized form, a general appraiser may simply tick "Solar Present" without assigning monetary adjustment. Document Performance History: Maintain a binder with 12–24 months of post-installation utility bills, monitoring app production logs (kWh generated), and transferable panel/inverter warranty documents (typically 25-year manufacturer coverage). Align Roof and Panel Lifespans: Never install a 25-year solar array on a roof that has less than 10–12 years of remaining useful life. Buyers and home inspectors will penalize a solar installation if they face a $5,000+ detach-and-reset fee to replace an aging roof shortly after closing.