Room Additions
Brother & Brother Builders
Room additions represent one of the more transformative services within the broader construction and remodeling work of Brother & Brother Builders, the San Jose general contractor based at 3109 Stevens Creek Blvd Ste A in the 95117 area. When a household in Santa Clara County outgrows its current footprint, adding new square footage is often a practical alternative to relocating, and it sits naturally alongside the company's larger portfolio of home remodeling, custom home construction, and design-build work. This page profiles how room additions fit into what the business does and the communities where that work takes place.
How Room Additions Fit Into Brother & Brother Builders' Work
As a full-service general contractor, Brother & Brother Builders handles projects that range from kitchen and bathroom remodeling to new home construction, ADU construction, garage conversions, and second-story additions. Room additions draw on many of those same disciplines. A single project can touch architectural services, floor plan development, drywall repair, interior painting, flooring installation, and even smart home upgrades once the new space is enclosed. Because the company already works across these related trades, a room addition can be approached as an integrated whole rather than a series of disconnected tasks — from initial design through the finishing details that make an added room feel like part of the original house.
The company's design-build capabilities matter here. With access to 3D home design tools, modern home design services, and green building options, Brother & Brother Builders can help homeowners visualize how a proposed addition will relate to the existing structure before construction begins. That connection between design and building is particularly useful for additions, where matching rooflines, floor levels, and finishes to the current home is often the difference between a seamless result and an obvious afterthought.
What a Room Addition Involves in Plain Language
In practical terms, a room addition means expanding a home's living space by building outward or reconfiguring existing structure to create a new room. That might be a larger family room, an extra bedroom, a home office, or an expanded living area. Unlike a cosmetic remodel, an addition typically requires new foundation or structural work, framing, roofing, electrical, and interior finishing so the added space integrates with the rest of the house. The table below outlines the general aspects homeowners tend to weigh.
| Aspect | What It Involves | Typical Considerations |
|---|---|---|
| Design & planning | Floor plan development and architectural services to shape the new space | How the addition connects to existing rooms and rooflines |
| Structural work | Foundation, framing, and roofing for the expanded footprint | Matching floor levels and load requirements of the current home |
| Systems | Extending electrical and preparing for smart home upgrades | Capacity of existing systems to serve added square footage |
| Interior finishing | Drywall, flooring installation, and interior painting | Blending finishes so new and old spaces read as one |
A Typical Sequence for This Kind of Project
- Discuss goals for the new space and how it should function within the existing home.
- Develop a floor plan and use 3D design tools to preview the addition alongside the current structure.
- Finalize architectural details, materials, and any green building or smart home elements.
- Complete foundation, framing, and roofing to establish the new footprint.
- Extend electrical and other systems into the added space.
- Install drywall, flooring, and finishes, then paint to unify old and new areas.
- Walk through the completed room to confirm it integrates cleanly with the rest of the home.
Serving San Jose and Santa Clara County Neighborhoods
Positioned along Stevens Creek Boulevard, a major commercial corridor linking San Jose with Santa Clara and Cupertino, Brother & Brother Builders is centrally located to reach homeowners across the county. Room addition work is available to residents throughout Central San Jose, North San Jose, and West San Jose neighborhoods including Winchester, Hamann Park, College Park, Fruitdale, Cadillac West, Blackford, North Willow Glen, Delmas Park, and Cambrian, as well as nearby communities such as Santa Clara, Campbell, Cupertino, Saratoga, Sunnyvale, Los Gatos, Monte Sereno, and Milpitas. Areas near landmarks like Westfield Valley Fair, Santana Row, the Winchester Mystery House, and the Municipal Rose Garden fall well within the company's service range.
This regional reach reflects the character of Silicon Valley housing. Many neighborhoods around San Tomas, Pruneyard / Dry Creek, Rancho Rinconada, Communications Hill, and the areas surrounding Central Park and Vasona Lake County Park feature established homes where an addition offers a way to gain space without leaving a familiar community. For families near Good Samaritan, Reed, Oster, Kooser, or Thousand Oaks, expanding an existing home can preserve proximity to schools, parks, and daily routines while adding the room they need.
What Distinguishes the Brand's Approach
What sets Brother & Brother Builders apart for this work is the breadth of its general contracting practice. Because the same company also handles custom homes, new home construction, kitchen and bathroom remodeling, and second-story additions, a room addition can be coordinated by a contractor already familiar with every stage of the build. Homeowners across San Jose and the wider Santa Clara County region can reach the company by phone at +1 888-412-2632 to learn more about how an addition might fit their home.
Getting here
From California's Great America
From California's Great America, it's about 1.9 miles and a 7-minute drive. The path takes Moorpark Ave and the San Tomas Expy before reaching Dorcich St and Brother & Brother Builders.
Common questions
How much would a 20x20 room addition cost in CA 95117?
A 400-square-foot room addition can vary widely depending on finishes, foundation work, and whether plumbing or electrical are involved. In higher-cost markets like the San Jose area, such projects often run into the tens of thousands and beyond. A general contractor like Brother & Brother Builders, based on Stevens Creek Boulevard, handles room additions across Santa Clara County and can scope pricing based on your site and design goals.
What is the average cost of adding a home addition in California?
Home additions in California typically cost more than the national average due to labor, permitting, and material prices, especially in Silicon Valley communities. Costs depend heavily on square footage, design complexity, and finish level. Brother & Brother Builders, a general contractor serving San Jose, Santa Clara, Cupertino, Sunnyvale, and nearby areas, offers room additions and second-story additions with design-build services that help homeowners plan realistic project scopes.
What is the most expensive part of an addition in CA 95117?
The foundation, framing, and any new mechanical systems, plumbing, electrical, and HVAC, are usually the costliest parts of an addition, alongside skilled labor. Roofing and matching existing structures add expense too. Brother & Brother Builders, a full-service general contractor in the San Jose area, manages these elements through design-build and room addition services so structural and system work is coordinated from the start.
Do I need a foundation for an addition in CA 95117?
Yes, most room additions require a proper foundation, whether a slab, pier-and-beam, or footings, to support the new structure and meet local building codes. The right choice depends on soil, design, and how the addition connects to your home. Brother & Brother Builders, serving San Jose and Santa Clara County, handles additions and new construction where foundation planning is part of the design-build process.
What is the cheapest way to add an addition to a house in CA 95117?
Converting existing space, such as a garage conversion, is often more economical than building new square footage from scratch, since the structure and foundation already exist. Bump-outs and simpler single-story additions also cost less than complex builds. Brother & Brother Builders offers garage conversions, room additions, and ADU construction throughout the San Jose area, giving homeowners several routes to added living space.
Can you pour a slab without footings in CA 95117?
For load-bearing structures like room additions, footings are typically required to distribute weight and satisfy building codes, though some non-structural slabs may differ. Local soil conditions and permitting play a role. A licensed general contractor such as Brother & Brother Builders, working across San Jose and Santa Clara County, can determine the correct foundation approach for your addition during the design-build phase.
How do you attach a room addition to an existing house in CA 95117?
Attaching an addition involves tying the new foundation, framing, roofline, and exterior into the existing structure, often requiring careful matching and proper flashing to prevent water intrusion. It must meet local codes and inspections. Brother & Brother Builders, a general contractor on Stevens Creek Boulevard in San Jose, coordinates room additions and second-story additions so the new space integrates soundly with the original home.