Your home, in the best hands.
We help you repair and remodel your home, easier and at a lower cost — roofing, windows and solar, all with one team.
Our own crew, certified materials and real work done in California. No subcontractors, no surprises.
Built on trust.
Cornerstone Holdings ©2026
Over a decade improving homes across California. Families protecting their investment with roofing, windows and energy built to last.
Finished roof · California
Real work, done by hand, in California.
Shingle, tile and metal installed by our own crew. GAF-certified materials and a written warranty.
Learn more →Double-pane glass that blocks heat, cold and noise. Installed in 1–2 days, clean home when we finish.
Learn more →Residential systems with 24/7 monitoring and a 25-year warranty. Your home makes its own energy.
Learn more →Upload a photo of your house and see it with a new roof, windows or solar panels in seconds.
Try the visualizer
AI VisualizerWe visit your home, check everything and explain. If you want, we can even sign the contract that same day.
We send your project quote and design, clear and in writing.
Our own crew, no subcontractors. Permits and inspection included.
We review with you that everything turned out perfect. You approve and sign off the project.
Real reviews from California clients. Roofs, windows and solar installed by our own crew.
San Jose, CA · New roof
«Insurance didn't want to pay for the new roof. Will helped me document everything and they ended up covering it. Zero stress, all legit.»
Verified customer
If it's over 15-20 years old, if you see loose shingles, stains on interior ceilings, or shingle granules in your gutters — it's time to inspect. We do free inspections and give you an honest report: if it still has years left, we'll tell you.
Asphalt shingle (most common and affordable), tile (concrete or clay), metal, and flat commercial roofs. Each has a different lifespan — 25-30 years shingle, 50+ years tile and metal. We help you pick based on your home and budget.
We replace the roof first, then install the panels. We'll advise you on the best order to save on permits and installation.
Depends on the damage and your policy. We help you document everything (photos, technical report, estimates) so you have the strongest possible case. We don't promise your insurance will pay — but we give you the tools to claim what's owed to you.
For an average California home, between $15,000 and $25,000 before incentives. With the 30% federal tax credit and $0-down financing, most of our clients pay less per month than their current electric bill.
Yes. The entire team — sales, design, installation, and support — is bilingual. All documentation is available in both Spanish and English.
A typical new roof takes 1-3 days. A 14-panel solar install takes 1-3 days. Design and permits add 2-4 weeks before that.
Both the new roof and the panels increase your home value. NREL studies show +$15,000 on average per installed solar system. Financing is transferable to the new owner.
Double-pane windows keep your home cool in summer and warm in winter, cut street noise and prevent humidity and mold. Your home feels better all year.
Most homes are done in 1 to 2 days. We remove your old windows and leave everything clean.
No. You can start with the ones you need most and continue later. At your free inspection we check how many qualify.