Professional and efficient service

We bring over 30 years of combined experience.

A team you can trust

We’ve helped over 2,000 clients between the two of us with our hands-on approach.

Cost-effective and sound advice

Your best legal interests are our highest priority.


We offer a wide array of residential and commercial legal services with an emphasis on real estate.

Real Estate Affairs

Real Estate Affairs

  • Property rights and land use disputes
  • Residential and commercial landlord-tenant matters co-ownership and neighbor disputes
  • Condo association and CC&R rules interpretation/advocacy
  • Commercial and residential leasing and mediation services
Real Estate Transactions

Real Estate Transactions

  • Purchase and sale agreements
  • Tenancy-in common agreements
  • Condominium conversion issues
  • Residential & commercial landlord-tenant counseling
  • Planning, zoning, and permitting issues


Representing ONLY LANDLORDS AND PROPERTY OWNERS regarding residential property issues in San Francisco County, our lawyers bring over 30 years of combined experience in representation in landlord/tenant disputes, San Francisco Rent Board hearings, mediations, arbitrations and other dispute resolution venues.

Preparation of and assistance with required notices pursuant to Section 37.9 of the San Francisco Rent Ordinance and as appropriate for prudent property management.



Representation of both landlords and tenants, including “small” property owners, in all aspects of lease negotiations, term extensions, lease assignments, wind-up of business lease termination agreements, exercise of option agreements, and document preparation for the refinancing of businesses (tenants) and properties (landlords).

Assistance with analysis of highest and best use of your property, including representation of your interests with lenders, private companies, and governmental agencies, including the City and County of San Francisco Departments of Planning, Building Inspection, Housing Inspection, Public Works and Assessor/Recorder.

Counseling on issues and aspects of re-zoning or change of use.

Assistance with documentation as required by the California Department of Real Estate for the purchase and sale of multi-unit properties (“Public Reports”).

Meet the Team

We bring over 30 years of combined experience in both residential and commercial real estate matters.

Denise A. Leadbetter

Denise A. Leadbetter


Denise graduated from Santa Clara University School of Law and is a member of the California Bar. She is admitted to appear before all courts of California, Federal District Court, and the U.S. Supreme Court.

Denise was a partner with Zacks, Utrecht, and Leadbetter in San Francisco before opening the Law Office of Denise A. Leadbetter in January 2009. Then, in November 2021, she and Thomas Koster partnered up to form Koster & Leadbetter.

Prior to her career as an attorney in private practice, Denise was In-House Counsel and Asset Manager for a property management company responsible for over 1 million square feet of investment property located throughout the San Francisco Bay Area.

Thomas Koster

Thomas Koster


Thomas graduated from Santa Clara University School of Law and is a member of the California Bar. He is admitted to appear before all courts of California and California Federal District Courts. Thomas and Denise have been working together since 2018 and became partners in November 2021. Prior to working with Denise, Thomas worked as a transactional attorney in-house at a tech company and then as a real estate litigator. Thomas is the firm’s primary trial attorney, but works as a transactional attorney as well, providing unique insight into potential risks and disputes that arise out of real property transactions.

3 easy steps to get started

You complete our inquiry form.

You provide a simple description of your legal matter or dispute.

We run a conflicts check.

We run a quick check to make sure there aren’t any conflicts in us working together.

We schedule a consultation call.

We’ll go over the more specific details of your issue so we can get started on resolving your issue.

Located in the historic Flood Building in San Francisco.

Located in the historic Flood Building in San Francisco.

Contact Us

Please fill out the below form and we’ll get back to you asap.

In 2-3 sentences, please describe your issue. We will get back to you as quickly as possible.

Koster & Leadbetter LLP
The Flood Building
870 Market Street, Suite 450
San Francisco, CA 94102

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