Structural tie-in
Foundation, floor framing and roof connections engineered to join the existing structure correctly.
Home additions • Livermore, California
Home Addition Contractor in Livermore, CA
New square footage that reads as part of the original house, not as something attached to it.
The measure of a good addition is that a visitor cannot tell where the old house ends. That comes from matching rooflines and wall planes, carrying trim profiles through, and getting the floor heights to meet without a step you have to explain.
We handle room additions, second stories and bump-outs from foundation and structural tie-in through envelope, windows and interior finishes, with the existing house protected while the new structure is dried in.
What the work includes
Handled properly, in the right order.
Envelope
Roofline, sheathing, weather barrier, windows and cladding matched to the existing house.
Systems extension
Electrical, plumbing and HVAC extended with the capacity the added space requires.
Interior finishes
Drywall, flooring, trim and paint matched so the new rooms read as original.
Project types
Work homeowners bring us.
Typical home additions projects we take on across Livermore, Pleasanton, Dublin, San Ramon and the wider Tri-Valley.
- Room additions
- Second-story additions
- Kitchen and living space bump-outs
- Primary suite additions
- Garage and workspace additions
- Enclosing patios and porches
Our process
From vision to completion.
The same four stages on every project, so you always know where things stand.
- 01
Consultation
We walk the space, listen to how you use it and define scope, priorities and realistic budget ranges before anything is promised.
- 02
Planning
Selections, sequencing, materials and schedule are documented so expectations are aligned before the first day of work.
- 03
Construction
Clean, protected job sites and coordinated trades. Progress is communicated and quality is checked as the work advances.
- 04
Final Walkthrough
We review the finished work together, address every detail on the list and hand over a project that is genuinely complete.
Questions
Straight answers.
Do additions require permits and plans?
Yes. Additions need drawings, structural engineering and a building permit. We manage the submittal and the inspections through completion.
Can you match my existing siding, roof and trim?
That is the goal on every addition. Where a material is discontinued, we will show you the closest option and where a transition should fall.
Is an addition better than an ADU?
It depends on what you need. An addition expands the house itself; an ADU creates a separate, independent unit. We will walk through both against your lot and budget.
Can we stay in the house?
Usually yes. The new structure is built and dried in before the existing wall is opened, which keeps the house closed up for most of the project.
Areas we serve
Based in Livermore. Working across the Tri-Valley.
Our office is on Walnut Street in Livermore, and most of our projects are within a short drive of it — through the Tri-Valley and out into the East Bay.
Primary service area
Livermore, California
Our home city and where our office is based, on Walnut Street.
- PleasantonTri-Valley
- DublinTri-Valley
- San RamonTri-Valley
- DanvilleSan Ramon Valley
- AlamoSan Ramon Valley
- BlackhawkSan Ramon Valley
- FremontEast Bay
- Castro ValleyEast Bay
- Walnut CreekEast Bay
Related work
Other scopes we handle.
ADUs
Accessory dwelling units built as complete, livable homes — permitting and utilities through compact kitchens and baths.
View adusHome Remodeling
Whole-home and multi-room renovations coordinated by one contractor, from framing changes through final paint.
View home remodelingGeneral Contractor
Licensed California general contractor handling residential construction and remodeling across Livermore and the Tri-Valley, CSLB #1158878.
View general contractorRoofing
Roof replacement and repair executed as a complete system — decking, underlayment, flashing, ventilation and finish material.
View roofing
Next step
Tell us what you're planning.
Send the scope and timeline, or call us directly. K&M Properties Inc. is a licensed California general contractor, CSLB #1158878.