ADU Construction and Room Additions in San Diego's North County
TNT Design & Build is a contractor based in San Diego's North County, specializing in the design and construction of accessory dwelling units (ADUs), garage conversions, and room additions. With 15 years of experience in the industry, the company manages projects in-house from initial planning through to completion.
ADUs offer California homeowners a practical way to add usable space to their property — whether as a comfortable living arrangement for parents or extended family, or as a rentable unit that generates additional income. TNT Design & Build works with clients to design and build ADUs that suit their specific needs and property layout.
One area where TNT Design & Build has developed particular expertise is garage conversion. Under California's updated ADU laws, converting an existing garage into a livable and rentable accessory dwelling unit has become a more accessible option for many homeowners. TNT Design & Build handles the full scope of these projects, including interior design, exterior work, permitting, and construction, with the goal of delivering on time and within the agreed budget.
The ADU Process
TNT Design & Build follows a structured process for each ADU project:
- Consultation and Design: The process begins with an in-depth consultation to understand the client's goals. The design team then develops detailed plans focused on functionality and aesthetics.
- Permitting and Regulatory Support: The company manages all necessary paperwork and ensures compliance with local zoning laws and building codes.
- Construction: The construction team coordinates all aspects of the build, including site preparation, foundation, framing, plumbing, electrical, HVAC, and interior and exterior finishes.
- Quality Assurance: Quality control measures are applied throughout each phase of construction to maintain consistent standards.
TNT Design & Build offers free architectural design for qualifying projects, with ADU pricing starting at $325 per square foot. The company also provides a guaranteed budget and a guaranteed timeline. If a project is not completed by the agreed-upon date, TNT Design & Build applies a credit of $250 per day off the remaining balance until the work is finished.
Room Additions
In addition to ADU construction, TNT Design & Build offers custom room additions for homeowners looking to expand their living space. Whether the need is an extra bedroom, a home office, or a guest room, the company manages the entire process — from planning and permits through to final construction.
Room additions can increase a property's market value by adding square footage, while also improving day-to-day functionality for the household. TNT Design & Build approaches these projects with the same in-house management structure used for ADU builds, aiming to minimize disruption and keep the project on track.
For homeowners in San Diego's North County considering an accessory dwelling unit, a granny flat, a casita, or a room addition, TNT Design & Build provides a full-service option that covers design, permitting, and construction under one roof.
