top of page


Prufen, LLC (Prufen) was established with a purpose to provide premiere construction cost estimating services for the building industry. At the core of this purpose is Prufen’s philosophy of providing transparent, independent, and defensible cost analysis. Prufen is a small firm, and that is by design. Clients have our leadership's undivided attention, and we believe that is the way it should be.


Prufen is positioned to advocate on behalf of clients throughout the various sectors of the building industry. This includes public agencies (local, state, & federal), construction companies, third party administrators, law & insurance firms. Prufen’s construction cost estimating services can be provided in the pre-construction, construction, and post-construction phases of a project.


Please feel free to reach out to us and to discuss your next project. We enjoy our work and would appreciate an opportunity to share that enthusiasm with you.


Prufen is recognized as a micro small business by the State of California (CA-DGS SB#2006-493)



Brandon Rosenthal has extensive experience in the building industry, having worked on over $2 billion worth of projects across various sectors, including healthcare, aviation, ports, education, and commercial. He has worked in the pre-construction, construction, and post-construction phases of both public and privately funded projects.

Brandon's approach to problem-solving is grounded in thorough research, robust analysis, effective information management, and steadfast advocacy, which he applies to his cost-estimating work. He has been a Certified Professional Estimator (CPE) in good standing with the American Society of Professional Estimators (ASPE) since 2009. He is transparent and maintains effective communication with stakeholders throughout the estimating process, which includes understanding the scope of work and contract, selecting the appropriate estimate template, performing quantity takeoff, researching and developing material, labor, and equipment costs, markup costs per contract or market conditions, presenting the estimate to stakeholders, and documenting the negotiation process.


Brandon's passion for cost-estimating began organically while working in management and operations, where estimating was part of his job description. He is enthusiastic about the art & science of cost estimating and looks forward to sharing his expertise with you on your next project.

Certifications & Education

Certified Professional Estimator (CPE)

Certified Construction Manager (CCM)

Certified Planning and Scheduling Professional (PSP)

Certified Leadership in Energy and Environmental Design Professional (LEED AP BD+C)

Certified Commercial Building Inspector

Certified Structural Masonry Special Inspector

Licensed Contractor (C-29), State of CA (Inactive Status)

BA, University of California at Los Angeles

MBA-Business Analytics, California State University at Fullerton


Cost Management Services

The clients we can serve include public agencies, designers, insurance companies, law firms, real estate firms, contractors, developers, commercial companies, and home-owners associations.


Cost Estimating

  • Design Cost Estimating (Conceptual thru to Construction Document)

  • Change Order Estimating / Negotiation

  • Job Order Contracting (JOC)

  • Cost-to-Complete

  • Lump Sum / Time and Material Audit

Construction Management

  • Owner's Representation

  • Construction Monitoring

  • Quality Control / Assurance

  • Inspection Oversight / Observation

  • Agency Coordination

Claims Analysis & Litigation Support

  • I​nsurance Appraisal Cost/Scope Analysis

  • Cost Estimating of Disputed Project Costs Due to Loss or Construction Defect

  • Analysis and Reporting of Estimating Methodologies Employed by Others

Contract Administration

  • Onsite Advocacy

  • Information System Management

  • Document Controls


Contact Us

Thanks for submitting!

Let's connect to discuss your next project today.

  • LinkedIn
  • Facebook
  • Twitter
  • Instagram
bottom of page