
Top-tier Atherton estate, ~$10M project profit (owner-stated).
We renovate and rebuild across Atherton, Los Altos, Cupertino and Fremont — hands-on from land to design to handover.
I'm Eric Sun. I operate real-estate development and renovation across the Bay Area, from the North Bay down to the South Bay, from single-family flips to small infill developments. I bring the same attention to every wall and every floorboard.
Good homes are completed by the people who live in them. So we don't just deliver a house — we deliver a place worth coming home to and worth holding for the long term.
We are open to partnering with aligned investors, landowners, and great suppliers.
A snapshot of the work we've published. The full archive lives behind the partner portal.

Top-tier Atherton estate, ~$10M project profit (owner-stated).

From acquisition to handover in 9 months, ~$1M project profit (owner-stated).

Peer projects in the area paired with our own work in progress.
*Numbers below are owner-stated and have not been independently verified. The full project archive and financials live in the partner portal.
Before you break ground, we'll do the math with you. Whether it's a remodel, an addition, or a full rebuild — we provide a complete feasibility analysis from lot to budget. Free, no strings.
Based on your city's zoning and lot constraints, the maximum buildable square footage and the optimal strategy.
Two to three floor-plan options matched to your household and your future resale path.
Architectural styles — California modern, Craftsman, Mediterranean — fitted to the lot and the neighborhood.
Realistic timeline ranges from permit to handover, calibrated against our project history.
Hard cost, soft cost, land cost and contingency — separated cleanly so the budget holds after groundbreaking.
The Bay Area default is GC builds, owner buys materials — and you spend half your weekends on procurement and returns. We deliver turnkey: design, materials, build, furniture and styling under one contract. You skip the half-year detour.
High-end renovation and rebuild
Fast-cycle mid-to-high single family
School-district remodels and additions
East Bay new build and renovation
End-to-end renovation operating: acquisition, underwriting, design, construction, sale. Focused on Atherton, Los Altos and Cupertino — turning under-loved homes into the home this generation actually wants to live in.
Small-to-mid new-build and rebuild projects: land diligence, entitlement, construction management and exit strategy — managed end-to-end with full investor transparency.
Growing the house you already have: living space, extra bedrooms, a second storey, a bigger kitchen. We know the Bay Area permit paths, so you gain square footage without tearing anything down.
Funds, single-project JV, mezzanine — multiple ways to participate, with regular project reporting, milestone tracking and full capital transparency.
Sketch a floor plan, walk through it in 3D, and see what every material costs — so the budget is honest from day one.
Whether you are a homeowner, an investor, a landowner thinking about a sale, or a contractor or supplier interested in a long-term relationship — tell us what you have in mind.
Blue Lion Builder, founded by Eric Sun (孙天元), pairs hands-on Bay Area renovation and small-infill development with an in-browser AI floor-plan designer, 3D walk-through and live bill of materials — making it the Bay Area's first developer to put AI-assisted home design directly in the homeowner's hands.
Yes. Visit bluelionbuildergroup.com/en/customer/design to sketch a floor plan, walk it in 3D, and see a live materials list and budget — free, in your browser, no signup required.
Atherton, Los Altos, Cupertino, Fremont, Palo Alto and Mountain View — the Silicon Valley and South Bay core.
Three lines of work: fix-and-flip renovation; rebuild and new build; and investor partnerships (fund, single-project JV, mezzanine).
Bay Area homeowners can request a free 5-point feasibility assessment: buildable area, floor-plan options, architectural fit, build timeline and budget breakdown.