21217 Washington Ave #28 · Diamond Bar, CA 91789

$308,000

3 bd · 2.0 ba · 1,440 sqft · Manufactured public records · 6 Days on market

Built 1982 Est $230k · 34% over

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Why this score? — see what drove the C+ grade

The composite is a weighted blend of 9 inputs, each scored 0–100. Each bar is that input's sub-score; the figure is the points it added to the 100-point composite (weight × sub-score).

• Cash flow +28.5/30.0
• DSCR +10.0/10.0
• 1% rule +7.9/10.0
• Schools +6.9/10.0
• Livability +3.9/5.0
• Rent growth +2.6/5.0
• Condition / age +2.5/5.0
• ARV discount +0.0/15.0
• Appreciation +0.0/10.0

Listing remarks MLS

Accepting Back Up Offer ! Located in a quiet and secured gated mobile home community. Amenities includes club house, swimming pool, in-ground spa, basket ball court & play area. Excellent "Walnut Valley School District" * Convenient location with easy access to major Freeways 60 & 57, Metro-link & Nearby Shopping Area Spacious double wide manufactured home with open floor plan, living room with fireplace, Master Bedroom with walking closet. Covered porch & Beautiful landscaping.

Key facts

• Dual-pane windows
• Remodeled kitchen
• Upgraded gas stove

Tags

• REMODELED KITCHEN
• DUAL-PANE WINDOWS
• UPGRADED GAS STOVE
• UPGRADED WATER HEATER
• NEW ROOF
• UPGRADED FIREPLACE

Property features AI

Finance

• Other: Park name: Diamond Bar; Manager approval required for residency; Pets: contact management
• HOA & community: Land lease community (land lease $1,395)

Exterior

• Parking: Covered parking; Gated parking area; 3 parking spaces (includes 3 carport spaces)
• Security: Gated community
• Utilities: 220V electrical throughout; Public/district water; Public sewer (sewer connected)
• Home design: Manufactured home (Madison model), double body; Single-story; Entry through gated community; Mobile home remains
• Construction: Wood construction with drywall walls; Concrete slab foundation; Built/updated and remodeled (year built from assessor)
• Exterior features: Shingle roof; Porch and deck with wood and brick elements; Patio; Storage building (1 shed); Community pool; Close to clubhouse; Street lighting in neighborhood

Interior

• Kitchen: Gas range; Water line to refrigerator; Pots & pan drawers; Gas water heater
• Flooring: Tile flooring; Vinyl flooring
• Bathrooms: 2 full bathrooms; Bathtub; Low-flow shower
• Heating & cooling: Central heating (central furnace); Central cooling
• Interior features: Quartz counters; Storage space; Double pane windows; Window screens; One-level entry (gate)
• Laundry & utility: Laundry room; Gas dryer hookup

What this means for you Summary

Snapshot

• This is a 3-bed/2.0-bath manufactured listed at $308k.

Deal economics

• At list price, monthly cash flow is $1k ($12k/yr) — positive.
• The deal already cash-flows at list — no discount required.
• Meets the 1% rule at list price ($4k rent vs $308k).
• Cap rate 10.2% vs local median 2.1% in Diamond Bar — top-decile yield for the area; either an underpriced asset or a hidden risk that comps aren't pricing in. Stress-test before assuming the spread holds.

Location & tenants

• Location reads 77/100 on livability (#86 in CA, #3,131 nationally) — a middle-class / working-renter tenant base. Strengths: amenities A+, employment A+, schools A-; Watch: health & safety D+, cost of living F.
• Walnut Valley Unified (suburban): math 74% / reading 79% proficiency, ranked #32 of 517 in CA (top 6%) — strong family-tenant draw, lease renewals of 3-5y typical; only 11% free/reduced lunch — higher-income household profile.
• Market conditions: Rents flat; 137 active listings in the ZIP; 9 comparable units currently listed for rent nearby; rentals leasing fast (median 11d on market — plan ~1-2 weeks tenant-placement turnaround); high-income renter base; 19,697 units permitted in Los Angeles County in 2024 (9,426 in 5+ unit buildings).
• This rent runs 38% of the median local income ($126k/yr) — at the standard rent-burdened threshold; future hikes will face affordability resistance.

Forward outlook

• Local home prices are declining (-3.0%/yr); year-one equity from $2k of loan paydown is wiped out by about $9k of value loss. Plan a longer hold.
• Los Angeles County population projected at +9% by 2050 — modest demand growth; plan on rents tracking national, not racing it.

Negotiation context

• Only 6 days on market — expect competitive offers; lowballing is unlikely to land.
• 3 sale attempts since 6y ago with the ask held roughly flat each time — persistent listings suggest the price (not the market) is what's stuck; bring a comps-based counter.
• Current owner paid $100k; list at $308k implies a 208% gain — meaningful room to come down on a strong offer.

Risks & watch-outs

• Climate carrying-cost: extreme-heat days projected 7→22/yr by 2055 (HVAC capex compounding) — expect insurance premiums to compound above CPI over the hold.

Recommended offer $308,000

Questions for the listing agent

1. Is there a deadline driving the sale (1031 exchange, divorce, estate, relocation)? That informs how much negotiation room exists.
2. Schools are A-rated — typically a magnet for longer-tenancy family renters. What's the average tenant stay here, and is there a school-zone premium baked into asking?
3. What's the average days-on-market for RENTAL listings here right now (not sales)? A rising rental-DOM trend means longer vacancies and softer asking-rent achievability than the comps imply.
4. What's the recent tenant-quality profile in this submarket — average credit score on applications, eviction rate, late-payment / NSF rate, and stable-employment percentage? A property-management company in the area should have these aggregated.
5. How much new for-sale + rental construction is in the pipeline within 1–3 miles? Heavy new supply typically softens prices + rents 12–24 months out; constrained supply supports both.

Investment metrics

• 1% rule: 1.29% ✓
• Cap rate: 10.19%
• Cash-on-cash: 13.94%
• DSCR: 1.62
• GRM: 6.5

CMA / ARV

• ARV (on-the-fly): $230,400
• Comps found: 3

Show comp detail 3 sales within ~0.75 mi

Address	Dist	Beds/Ba	Sqft	Sold	Price	$/sf	Match
21217 Washington Ave #112	0.00mi	2/2.0 (-1)	1,248 (-13%)	19mo	$193,000	$155	57
20739 Lycoming St #117	0.62mi	2/2.0 (-1)	1,446 (+0%)	16mo	$261,000	$180	52
20739 Lycoming #112	0.56mi	2/2.0 (-1)	1,248 (-13%)	7mo	$200,000	$160	41

Match score weights: distance 35% · size 25% · config 20% · recency 20%. Top-matched comps best support the ARV.

Projected returns pro-forma

-3.0% appreciation · 0.35% rent growth · sell at horizon

5-year hold

• IRR: 1.1%
• Equity multiple: 1.04×
• Total profit: $3,644
• Equity at exit: $45,924

10-year hold

• IRR: 7.9%
• Equity multiple: 1.53×
• Total profit: $45,500
• Equity at exit: $26,630

Cash invested: $86,240 (down + closing). Projections, not guarantees.

Landlord ↔ Tenant lean methodology

• Overall (STATE): 18 Strongly Tenant-Friendly
• State California: 18 Strongly Tenant-Friendly · D+13
• County: — inherits STATE
• City: — inherits STATE

AB1482 statewide rent cap (10% + CPI). Cities (SF/LA/Berkeley) layer stricter rules. Just-cause statewide.

Methodology + full state rankings →

ZIP-level market 91789

• Rents YoY: 0.3%
• Active inventory: 137
• Price-to-rent: 6.5×

Monthly cashflow live

• Estimated rent: $3,962 high
• Mortgage (P&I): −$1,615
• Tax est. 1.5%: −$385 /mo · $4,620/yr
• Insurance: −$128
• HOA: −$0
• Vacancy / Maint / Mgmt: −$832
• Net cashflow: $1,001

Break-even live

Break-even rent $2,694

Max offer price $308,000

Occupancy floor 70%

UW: 25.0% down · 7.5% · 30yr · 1.5% tax · 5.0% vac · 8.0% maint · 8.0% mgmt

Financing live

Cash to close

• Down payment: $77,000
• Closing costs: $9,240
• Reserves months: —
• Total cash needed: —

Rent comps 9 comps

Address	Beds	Baths	Sqft	Rent	$/sqft	DOM	Units	Dist
831 Windwood Dr Walnut, CA	3.0	1.5	1136	$3,050	$2.68	3d	1	0.30mi
20980 Cornerstone Dr Walnut, CA	4.0	3.0	1760	$3,975	$2.26	1d	1	0.70mi
21000 Cornerstone Dr Walnut, CA	4.0	3.5	1830	$4,200	$2.30	1d	1	0.71mi
21038 Cornerstone Dr Walnut, CA	4.0	3.5	1830	$3,975	$2.17	10d	1	0.71mi
20537 Vejar Rd Walnut, CA	3.0	2.0	1396	$3,800	$2.72	43d	1	1.12mi
248 Centinary Dr Walnut, CA	3.0	2.0	1429	$3,750	$2.62	43d	1	1.14mi
268 Centinary Dr Walnut, CA	3.0	2.0	1476	$3,700	$2.51	10d	1	1.17mi
268 Macalester Dr Walnut, CA	2.0	2.0	1008	$3,350	$3.32	7d	1	1.37mi
22808 Hilton Head Dr #28 Diamond Bar, CA	2.0	2.0	934	$2,550	$2.73	18d	1	1.49mi

Listing history 6 events

1. 2026-06-18
   days on market $308,000 Active 6 DOM
2. 2026-06-17
   days on market $308,000 Active 5 DOM
3. 2026-06-16
   days on market $308,000 Active 4 DOM
4. 2026-06-15
   days on market $308,000 Active 3 DOM
5. 2026-06-13
   remarks 699-char remark
6. 2026-06-13
   listed $308,000 Active 1 DOM

ⓘ Source: listings_history table (triggers on properties + properties_extension) + one-shot backfill from property_details.listing_events for pre-trigger history.

Climate risk First Street

• 🌊 Flood 1/10 Low FEMA zone X (unshaded) · 0% chance over 30 yrs
• 🔥 Wildfire 1/10 Low
• 🌡 Heat 7/10 Severe 7 d/yr ≥98°F today · 22 d/yr by 30 yrs out
• 💨 Wind 1/10 Low
• 🫁 Air quality 6/10 Major 10 unhealthy d/yr today · 13 by 30 yrs out

Taxation est. · year 1

• Rental income: $47,544
• − Mortgage interest: −$17,253
• − Property taxes: −$4,620
• − Insurance: −$1,540
• − Repairs & maintenance: −$3,804
• − Management: −$3,804
• − Depreciation: −$8,960
• Taxable income: $7,565
• Est. tax owed @ 24.0%: −$1,815
• After-tax cash flow: $10,202/yr

For passive investors: Depreciation is non-cash, so a rental often shows a tax loss while cash-flowing — sheltering income. Rental losses are passive: they offset passive income freely, and up to $25,000/yr can offset ordinary (W-2) income if you actively participate and your MAGI is under $100k (phasing out to $0 by $150k); unused losses carry forward. On sale, claimed depreciation is recaptured at up to 25%, and gains may owe capital-gains tax (a 1031 exchange can defer both). Figures are a year-1 estimate at your 24.0% rate — not tax advice; consult a CPA.

Schools (NCES district)

• District: Walnut Valley Unified
• NCES district ID: 0641280
• Math proficiency: 74% ▼ -1.00%
• Reading proficiency: 79% ▲ 2.00%
• Median HH income: $93,189
• Composite: 68.87/100
• National rank: #328
• State rank: #32 of 517 in CA

Livability — Diamond Bar

• Score: 77/100
• State rank: #86
• US rank: #3131

Category grades

Amenities A+ Commute A- Cost of living F Crime A- Employment A+ Housing C Health & safety D+ User ratings A+

Schools grade is shown separately in the Schools card above.

Census & demographics

• Census place: Diamond Bar, CA
• County: Los Angeles County · 9,444,647 people
• City population: 44,502
• Metro: Los Angeles-Long Beach-Anaheim, CA
• Population (ZIP): 40,298
• Household income: $125,720
• Rent vs Own: 17.9% rent · 82.1% own
• Severe rent burden: 603.0

Population outlook (Los Angeles County) Hauer SSP2

• Today (2025): 10,940,515 people
• By 2030: 11,256,481 · +2.9%
• By 2040: 11,729,929 · +7.2%
• By 2050: 11,948,407 · +9.2%
• By 2075: 11,818,114 · +8.0%
• By 2100: 10,842,928 · -0.9%

Race, ethnicity, and origin ACS 2023

• Neighborhood character: Predominantly Asian (67%)
• Race & ethnicity: Asian 67% Hispanic / Latino 18% White 9% Two or more races 7% Black 2%
• Hispanic origin (detail): Mexican 15%
• Foreign-born: 51% · China, South Korea, Canada
• Languages at home: 33% English-only · Chinese 38% Spanish 9% Tagalog/Filipino 6%

Political lean MEDSL · Los Angeles

• 2024 margin: Solid D (+32.9) · D 64.8% · R 31.9% · Other 3.3%
• 2008→2024 swing: -7.4pp toward R · 2008: 40.4pp · 2024: 32.9pp
• All cycles: 2024: D+32.9 2020: D+44.2 2016: D+48.0 2012: D+40.0 2008: D+40.4

Not yet ingested

• Civics: —

Market trends

• HPI YoY: ▼ -884.62%
• Current HPI: 368.0775
• Rent YoY: ▲ 0.35%
• Metro: Los Angeles-Long Beach-Anaheim, CA
• State GDP YoY: ▲ 3.21%
• F500 in state: 116

Industry mix (Fortune 500 HQ in CA)

Industry	F500 HQs	Revenue
▸Technology	27	$1,492B
▸Financial Services	3	$174B
▸Retail	3	$44B
▸Insurance	3	$26B
▸Media / Entertainment	2	$115B
▸Pharmaceuticals / Biotech	2	$62B

Price history

+131.6% since first listed

8 events — show timeline

• 2026-06-12 Listed $308,000 CRMLS
• 2020-09-29 Sold (MLS) $100,000 CRMLS
• 2020-09-09 Contingent — CRMLS
• 2020-08-27 Price Changed $110,000 CRMLS
• 2020-07-17 Price Changed $120,000 CRMLS
• 2020-06-22 Relisted — CRMLS
• 2020-06-10 Contingent — CRMLS
• 2020-05-21 Listed $133,000 CRMLS

Property tax history

+6.7%/yr

Latest (2025): $520 · +6.7% YoY. Source: county tax records.