# House Hacking in Castro Valley (94546): SB 79 densities at Castro Valley BART · The Rent Hacker

> Castro Valley 94546 for house hackers: In-ZIP Castro Valley BART (Blue line) with MTC TOC Tier 3 and SB 79 upzoning (50–75+ du/ac within a half mile, parking

Canonical: https://therenthacker.com/house-hacking/castro-valley-94546/
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[East Bay guide](/house-hacking/east-bay/) · Tier A · Rank #17 of 87

# House hacking in Castro Valley (Castro Valley central).

In-ZIP Castro Valley BART (Blue line) with MTC TOC Tier 3 and SB 79 upzoning (50–75+ du/ac within a half mile, parking maximum 1.0), plus Eden Medical Center's Level II trauma anchor.

## What's actually happening in 94546

-   Adopted / effective 2026-07-01
    
    Castro Valley BART with MTC TOC Tier 3 and SB 79 upzoning: 50–75+ du/ac within a half mile of the station, parking maximum 1.0. [Alameda County](http://www.acgov.org/board/bos_calendar/documents/CDAMeetings_01_13_25/CV%20MACTOC%20Presentation011325Final.pdf)
    
-   Update underway
    
    CBD Specific Plan update underway. Alameda County
    
-   Existing anchor
    
    Eden Medical Center (Level II trauma) in-ZIP. Alameda County
    
-   Under construction / delivered
    
    The Chapter townhomes and Crescent Grove (72 affordable units). Alameda County
    

## The numbers

Median price

~$1.3M (Castro Valley proxy)

Market rent

2bd $2,600 / 3bd $3,200 whole-home (underwriting band)

Property tax (Alameda County)

~1.33% effective (Castro Valley)

Per-bed rent band

$1,000–1,350/mo per bed

ADU rent band

$2,000–2,600/mo

Whole-home rent band

2bd $2,600 / 3bd $3,200 whole-home

Underwriting vacancy

5% underwriting vacancy

Appreciation scenarios

1.5 / 3.0 / 4.0 %/yr (conservative / base / upside)

Viability graded medium at this basis. Appreciation basis: BART plus TOC/SB 79 densities; SB 9 hillside-constrained; mid capex. Rent bands are city-level medians; confirm the specific parcel before trusting any of them. [Run your own scenario in the calculator](/calculator/).

## Buildings we underwrote in 94546

3 buildings in 94546 carry a record. 0 beat renting and index funds; the rest did not. Every row links to its own page, with the numbers it was scored on.

Property

At our defaults

Status

[20275 Stanton Ave](/property/rh-an9ywm/20275-stanton-ave/) 2 units · $999,000

−$580,202 S&P 500

Underwritten — the index wins at our defaults

[20942 Wilbeam Ave](/property/rh-d1httm/20942-wilbeam-ave/) 2 units · $950,000

−$591,489 S&P 500

Underwritten — the index wins at our defaults

[20843 Chester St](/property/rh-j8hrou/20843-chester-st/) 2 units · $1,409,800

−$1,320,282 S&P 500

Underwritten — the index wins at our defaults

The full [board](/board/) shows every region's current week; this table is every record we hold for 94546, newest basis first.

## The house-hack angle

SFH-with-ADU near the station under the new TOC and SB 79 densities; room rentals to Eden Medical staff. SB 9 is hillside-constrained here.

## What breaks it

-   A ~$1.3M basis pressures a 3–10% down buyer: run the numbers cold
-   SB 9 lot splits are hillside-constrained
-   The CBD Specific Plan is an update in progress: designation ahead of capital

This page is the standing analysis. The weekly part, actual Castro Valley-area listings that pass the math, lands on the East Bay board every Wednesday.

[This week's East Bay board](/board/sf-east-bay/)

[This week's East Bay board](/board/sf-east-bay/) · [Read past East Bay issues](/issues/sf-east-bay/) · [Every pick, on the record](/track-record/) · [How a deal becomes a pick](/methodology/)

Data synthesized 2026-07-04, catalysts re-verified 2026-07-15. Mortgage-rate basis: 6.43% (Freddie Mac PMMS, week of 2026-07-02). Sources are the public planning documents and market listings named above, fetched on the synthesis date. Nothing here is investment advice; every deal needs a bindable insurance quote and parcel-level verification.