Investor Profile - WA

Sid Constantinescu

Sid Constantinescu is a real estate investor and operator based in Seattle-Tacoma, WA. Public filings show activity across 116 properties held through 20 holding companies. Recent mortgage relationships include Builders Capital, Sound Capital, and ICAP EQUITY.

Contact info available

Sid's Activity

As of May 2026, public records show approximately $73.9M in recorded mortgage exposure linked to this investor across at least 126 mortgage filings and 116 properties held through 20 holding companies. Activity appears concentrated in residential and vacant assets recorded between 2016 and 2023.

Primary Geography

Seattle-Tacoma, WA

ZIP codes: 98144, 98332, 98221, 98366, and 98126

Most activity in SEATTLE, GIG HARBOR, ANACORTES, PORT ORCHARD, and KIRKLAND.

Property Type Breakdown

Residential88%
Vacant9%
Exempt2%

Associated Entities (20)

ROCK RIVER HOMES LLC

WA · 2 properties · 20 mortgages

inactive
Incorporated on 05/26/2017 in WAMailing Address: 17837 - 1ST AVE SOUTH, NORMANDY PARK, 98148, WA, UNITED STATES
ALEXANDER APARTMENT GROUP I LLC

WA · 1 property · 18 mortgages

inactive
Incorporated on 09/10/2007 in WAMailing Address: 3705 NE 157TH ST, LK FOREST PK, 98155-6647, WA, UNITED STATES

+18 more entities not shown

Mortgages (126)

DateAmountStatusLenderBorrowerAddress
10/27/2020$2.3MClosedPIERCE GROUP MASTER ENDOWMENT CARE FUNDKASTLE ENTERPRISES LLC7831 VAN BELLE RD,
SUNNYSIDE, WA 98944
10/26/2020$2.3MOpenPIERCE GROUP MASTER ENDOWMENT CARE FUNDKASTLE ENTERPRISES LLC12712 GRAVELLY LAKE DR SW,
LAKEWOOD, WA 98499

+124 more not shown

Owned Properties (116)

AddressDeeded ownerStatusConsideration
10162 HOLMAN RD NW #B,
SEATTLE, WA 98177
ALLISON MATSONSold$630k
707 SUNSET BLVD NE,
RENTON, WA 98056
1 SHARPE OPPORTUNITY IMMEDIATE TRUST LPSold$4.5M

+114 more not shown

FAQ

What type of real estate does this investor focus on?

Associated mortgages and deeds show activity in residential, vacant, and exempt properties across Seattle-Tacoma, WA.

What companies is Sid Constantinescu associated with?

Sid Constantinescu is associated with 20 entities based on extracted signatures from public records. Key entities include ROCK RIVER HOMES LLC, ALEXANDER APARTMENT GROUP I LLC, WATERSHED HOLDINGS LLC, LOTS PLUS LLC, and PACIFIC CREST REALTY ADVISORS LLC.

How many properties are associated with this investor?

At least 116 properties are associated with Sid Constantinescu and the entities they control, based on signatures extracted from recorded documents connecting Sid Constantinescu to the entities.

Which lenders has this investor worked with?

Recent mortgage activity references Builders Capital, Sound Capital, and ICAP EQUITY, indicating a mix of lending relationships.

How recent is their activity?

Records show activity from 2016 through 2023, with the most recent mortgage recorded in 2020.

How is associated activity determined?

Elementix uses AI to extract signatures from recorded documents. These signatures are used to determine the relationships between people and entities. This is a novel approach that goes beyond looking at corporate filings and skip-tracing.

The information displayed on this page is compiled from recorded real estate documents, business filings, and other lawfully available sources. Elementix summarizes and analyzes public record activity related to investment real estate and associated business entities. Any contact indicators shown (such as email domain references or partial phone digits) are provided solely as unverified signals and may be incomplete or outdated.

Elementix is not a consumer reporting agency, and this information does not constitute a consumer report. The data may not be used to make decisions about an individual's eligibility for personal credit, consumer housing, employment, insurance, or any other purpose governed by the Fair Credit Reporting Act.

Elementix may suppress certain contact indicators where legally required or where appropriate for safety or privacy reasons. Requests for removal, suppression, or correction of information must be submitted to [email protected]. Elementix reviews such requests only where required by applicable law. General objections or unsupported demands do not create a removal obligation.