On this page
This site is for someone who owns a duplex in Los Angeles County and is thinking about selling it. If you live in one half and rent out the other, it's written with you in mind, since your own move, your tenant next door and the tax on your home all shape the sale. Shaya Lowenstein, a licensed agent with Lyon Stahl Investment Real Estate, writes it, and every rule here links to the law or agency page it comes from.
Who it's for and what it covers
The reader owns the duplex, alone or with a spouse, with brothers and sisters after an inheritance, or through a trust. Renters and people selling a single-family house will find less here, because the questions are the ones a two-unit owner runs into.
It starts with the buyer, since a duplex sells either to someone who will live in one unit or to an investor, and their loans treat your tenant's rent differently. From there it goes through the rent and eviction rules that reach your tenant, what happens if a buyer wants to move into the rented unit, the disclosures you owe, what to do about a unit built without permits and what ADU law and SB 9 might add to the lot. The tax on each half gets its own treatment, with a calculator that shows how the gain splits between your home and the rental on your own numbers.
Where the rules come from
Each rule on the site is linked to the statute, court or agency page where it is written down. Those links go to the Civil Code on the Legislature's site, LAHD for the RSO and the Just Cause Ordinance, LADBS for permits and the City's property report, and the IRS for the home sale exclusion. Behind every page sits a file of research notes, one line per claim, recording the source and what it says.
When a fact couldn't be confirmed, it was left out. LAHD's relocation amounts are the plainest case. They change every July 1, no source at hand gave this year's figures along with the period they cover, and so the owner move-in page sends you to LAHD's own chart instead of printing a number that could be stale.
You also won't find market numbers. There are no cap rates, prices per unit or days on market anywhere on the site, because there is no dataset it could cite for them. Worked examples, like the one on the tax page, use made-up figures and say so.
Keeping the pages current
Whenever a law cited on a page changes, that page gets looked at again, and every page carries the date of its most recent change. There's no fixed review calendar, and no lawyer checks the pages before they go up, so look at that date before you rely on a figure. Some things turn over on a set day. LAHD's allowable rent increase and its relocation amounts move each July 1, and so do the Measure ULA thresholds, so check the linked source the week you act.
Who Shaya is
Shaya Lowenstein is a Multifamily Real Estate Advisor. His California Department of Real Estate license is #01942326, and you can look it up on the DRE's public license lookup. His responsible broker is Lyon Stahl Investment Real Estate, and the DRE's regulation on broker supervision requires that broker to supervise the advertising of any service that needs a license.
He has been in the business since 2011, and in that time he has worked in brokerage, in operations and in development. His work is apartment buildings and land across Southern California. That covers value-add work and repositioning, analysis of what zoning and land use allow on a lot, and long-term planning of a portfolio for owners, investors and developers. On a duplex, that zoning work means he can look at the lot as well as the two units, since the lot decides what a buyer could add.
What he does, and what he leaves to others
Shaya lists duplexes for sale, on the open market or quietly to buyers he finds, and his part is the price, the marketing, the choice of buyer and the timing, including when your own move happens and when your tenant hears about the sale.
He's a real estate agent. He isn't an attorney, a CPA or a tax advisor, and nothing on the site is legal or tax advice. The questions that belong to those professionals are marked where they come up, such as an attorney for an eviction notice or a disclosure exemption, and a CPA for how the gain divides between your unit and the rental. Take those to your own advisers, and bring Shaya the question of what the duplex should sell for and to whom.