The Peninsula · San Mateo County · Celebrity Mansion Estates
General Contractor
Celebrity-mansion territory — full-scale estate remodels, structural transformations, and grounds construction executed with total discretion.
JMG Construction Services — California Contractor's License #1007864 — delivers all sixteen of our in-house trades to Hillsborough and greater San Mateo County. From estate remodels and custom ADUs to roofing, electrical, plumbing, and commercial HVAC, every Hillsborough project is personally scoped by owner Jerry Guinn and executed by our own crews — never brokered to unknown subcontractors.
Whether the brief is a celebrity-grade whole-estate renovation, a discreet retail maintenance program, or a high-value ADU addition, our clients across San Mateo County get one contract, one schedule, and one accountable license.
Hillsborough requires design review through the Town's Building & Planning Department, and its hillside estates bring slope, drainage, and retaining-wall engineering into nearly every project. From Hillsborough Oaks to the Carolands area, we coordinate geotechnical reports, view-sensitive design, and the town's exacting inspection standards.
All services in Hillsborough
Recent work in the Hillsborough area
How projects run in Hillsborough
Private Consultation
Walk the property with owner Jerry Guinn. Honest scope, realistic timeline, and a written line-item estimate — free.
Design & 3D Rendering
See the finished project in photorealistic 3D before a single wall comes down. Finishes get locked before demo day.
Permits, Handled
Plans, submittals, corrections, and city or county coordination under CA License #1007864. You sign — we run the process.
Build & Final Inspection
Sixteen in-house trades on one schedule, one accountable owner. Inspection passed, walkthrough done, keys in hand.
Hillsborough construction — FAQ
Yes — JMG Construction Services holds California Contractor's License #1007864 and pulls permits in San Mateo County regularly. Every project is permitted, inspected, and signed off before we call it done.
Hillsborough Projects