Custom Residential
Structural engineering for one-of-a-kind houses: hillside cantilevers, open plans, ADUs, and additions.
Read moreEst. Southern California
Structural engineering for ambitious Southern California projects.
HJH Engineering partners with architects, developers, and general contractors from early concept through construction — translating architectural vision into code-compliant, buildable structure.
01 / What we do
Ten focused practice areas, one shared standard.
Our work spans ground-up new construction, adaptive reuse of existing buildings, and the specialty seismic and diligence work that Southern California projects require. Every engagement is led directly by the principal.
Project Types
Commercial
Ground-up and adaptive commercial structures — office, retail, restaurant, and light industrial.
Read moreTenant Improvement
Reworking existing structural shells to host new programs without disturbing the things you can't move.
Read moreMixed-Use
Retail-over-residential buildings where the structural grid has to serve two different programs at once.
Read moreMulti-Family
Apartment, condo, and small-lot subdivision structures — wood-frame podium to fully engineered CMU.
Read moreSpecialty Work
Due Diligence Studies
Pre-acquisition structural reviews that surface what a property will actually take to develop.
Read moreSeismic Retrofit
Strengthening existing buildings — unreinforced masonry, non-ductile concrete, and older wood frame.
Read moreFeasibility Studies
Fast, numbers-backed studies that confirm whether a structural idea pencils before design begins.
Read moreSeismic Evaluation
ASCE 41-based evaluations of existing buildings — Tier 1 through Tier 3, with a clear deficiency list.
Read moreSoft-Story Retrofit
Complete retrofit service under LA's Mandatory Soft-Story Program — screening through final sign-off.
Read more02 / Why HJH
Design-forward engineering, grounded in SoCal fundamentals.
We're small on purpose. The person you meet on day one is the engineer stamping your drawings — and the one answering the phone when something changes in the field.
01
Architectural partnership
We work alongside your architect from schematic design so the structural language supports — rather than fights — the architectural intent.
02
SoCal seismic expertise
We design for the realities of Southern California: hillside soils, unreinforced masonry, soft-story wood frame, and LA's retrofit programs.
03
Early-stage collaboration
The cheapest time to solve a structural problem is before it's drawn. We price ourselves into the concept phase and earn the savings back many times over.
04
Concept to construction
One engineer across feasibility, permit drawings, responses to plan check, and construction administration — with no loss of context between phases.
03 / Selected work
A few projects we've been part of.
04 / Founder
Led by Jack Hadjian, M.S., P.E.
Jack founded HJH Engineering after completing his Master's in Structural Engineering at the University of Southern California. He has since immersed himself in the design of new structures and the remodeling of existing ones across Southern California.
Read more about HJH →