Atherton · Renovation + Rebuild
Case 005 · Big stakes, wide margin
Top-tier Atherton estate, ~$10M project profit (owner-stated).
Twenty years on the ground in the Bay
Turning the Bay Area's older homes into the next family's first day.
We renovate, rebuild and add ADUs across Atherton, Los Altos, Cupertino and Fremont — hands-on from land to design to handover.
20+
Years operating developments
7+
Renovation cases on record
4
Bay Area neighborhoods we know cold
About Eric Sun · 孙天元
A developer who treats every project as a portfolio piece
I'm Eric Sun. Twenty years of real-estate development and renovation operating, 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.
- 20 years of hands-on development & flip operating
- Fix-and-flip, rebuild and ADU specialists in Silicon Valley
- Established cross-border supplier pipeline (incl. SSE-listed Chinese vendors)
- Open to investor and supplier partnerships
Selected cases
Let the homes do the talking
A snapshot of work we've published over the past two decades. The full archive lives behind the partner portal.
Los Altos · Fast cycle
Case 007 · Speed wins
From acquisition to handover in 9 months, ~$1M project profit (owner-stated).
Atherton · Walk-through
A walk through Atherton
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.
Free for Bay Area homeowners
5-point feasibility assessment
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.
01
Add-on potential
Based on your city's zoning and lot constraints, the maximum buildable square footage and the optimal strategy.
02
Floor-plan options
Two to three floor-plan options matched to your household and your future resale path.
03
Architectural direction
Architectural styles — California modern, Craftsman, Mediterranean — fitted to the lot and the neighborhood.
04
Build timeline
Realistic timeline ranges from permit to handover, calibrated against our project history.
05
Cost budgeting
Hard cost, soft cost, land cost and contingency — separated cleanly so the budget holds after groundbreaking.
Why us
A turnkey delivery model — rare in Silicon Valley residential
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.
Why it works
- One contract covers design, materials and construction
- Materials sourced through our own pipeline of established suppliers
- Timeline and budget locked — overruns are on us
- Warranty and post-handover service stitched in from day one
Where we focus
The zip codes we know cold
Atherton
High-end renovation and rebuild
Los Altos
Fast-cycle mid-to-high single family
Cupertino
School-district remodels and additions
Fremont
East Bay new build and ADU
On video
From case studies to market notes — updated weekly
What we do
From a parcel of land to a family at home
Fix & Flip 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.
Rebuild & New Build
Small-to-mid new-build and rebuild projects: land diligence, entitlement, construction management and exit strategy — managed end-to-end with full investor transparency.
ADU Additions
Garage conversions, detached ADUs, junior ADUs. Deep familiarity with Bay Area municipal rules — so we can unlock the most value out of your lot.
Investor Partnerships
Funds, single-project JV, mezzanine — multiple ways to participate, with regular project reporting, milestone tracking and full capital transparency.
For Bay Area homeowners
Design your home in your browser
Sketch a floor plan, walk through it in 3D, and see what every material costs — so the budget is honest from day one.
Let's talk
Build something worth delivering
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.
FAQ
Frequently asked questions
What does "Silicon Valley's first AI home builder" mean?
Tianyuan Homes, founded by Eric Sun (孙天元), pairs 20 years of 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.
Is the AI home designer free to use?
Yes. Visit tianyuanhomes.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.
Which Bay Area neighborhoods does Tianyuan Homes serve?
Atherton, Los Altos, Cupertino, Fremont, Palo Alto and Mountain View — the Silicon Valley and South Bay core.
What services does Tianyuan Homes offer?
Four lines of work: fix-and-flip renovation; rebuild and new build; ADU additions (garage conversions, detached ADUs, junior ADUs); and investor partnerships (fund, single-project JV, mezzanine).
How do I get started?
Bay Area homeowners can request a free 5-point feasibility assessment: buildable area, floor-plan options, architectural fit, build timeline and budget breakdown.