| Business | Phone |
| Arpen Group 11260 Wilbur Ave # 101, Northridge 91326 | (818) 360-5155 |
| Bannaoun Engineers Constructor Northridge 91324 | (818) 775-0040 |
| Design Engineering 18709 Lemarsh St, Northridge 91324 | (818) 885-1556 |
| AZ CIVIL ENGINEERING 18521 Mayall St. suite A, Northridge 91324 | (818) 687-4917 |