Home Addition vs Home Remodel: Expand or Transform?
Home additions add new square footage at $250-$500/sqft. Home remodels transform existing space at $150-$400/sqft. Choose an addition when you genuinely need more room. Choose a remodel when your space is adequate but does not work the way you need it to.
Should I add on to my house or remodel what I have?
Add on if you need more bedrooms, a bigger kitchen, or space your current layout cannot provide. Remodel if your square footage is adequate but the layout, finishes, or systems need updating. Additions cost $250-$500/sqft; remodels cost $150-$400/sqft. Many projects combine both: an addition plus remodeling of the existing space.
More Space or Better Space?
Your home does not quite work. Maybe the bedrooms are too small, or the kitchen cannot handle your family’s needs, or you simply need another bathroom. The question is whether you need more space or just better use of the space you have.
Quick Comparison
| Factor | Home Addition | Home Remodel |
|---|---|---|
| Cost | $250-$500/sqft | $150-$400/sqft |
| Timeline | 6-12 months | 4-8 months |
| Square Footage | Adds new space | Transforms existing space |
| Permits | Setback review required | Standard building permit |
| Disruption | Moderate to high | Moderate |
| Best for | Need more rooms/space | Layout or finishes need updating |
Home Additions: When You Need More Room
A home addition physically expands your house. This can mean a new wing, a second story, an extended kitchen, or additional bedrooms. Additions are the right solution when no amount of reconfiguring your current layout can give you the space you need.
Common Bay Area additions:
- Ground-floor bump-out (200-400 sqft): $50,000-$200,000. Extends an existing room or adds a small new room.
- Major ground-floor addition (400-800 sqft): $100,000-$400,000. Adds a primary suite, family room, or expanded kitchen.
- Second-story addition (600-1,200 sqft): $180,000-$600,000. Adds bedrooms, bathrooms, and an upstairs living area.
When an addition makes sense:
- You need more bedrooms or bathrooms than your current layout allows
- Your kitchen is too small to expand within the existing footprint
- You want a primary suite and there is no room to create one
- Your lot has room to build out (or your structure can support going up)
Home Remodeling: When You Need Better Space
A remodel works with your existing square footage. It can reconfigure walls, update every surface and system, and transform how your home looks and functions without adding a single square foot.
Common Bay Area remodel scopes:
- Kitchen remodel: $80,000-$200,000+
- Primary bathroom remodel: $40,000-$80,000
- Open floor plan conversion (removing walls): $30,000-$80,000
- Whole-home remodel (all rooms, systems, finishes): $150-$400/sqft
When a remodel makes sense:
- Your home has enough square footage but the layout is outdated
- You want an open floor plan where walls currently divide rooms
- Finishes, fixtures, and systems (electrical, plumbing, HVAC) need updating
- You are happy with the number of rooms but not their quality
The Combination Approach
In practice, many Bay Area projects combine both strategies. A typical scenario: add a 400 sqft primary suite to the back of the house while remodeling the existing kitchen and bathrooms. This delivers both the extra space you need and the updated quality you want.
The combination approach costs more than either option alone, but it is almost always more cost-effective than doing them as separate projects. Combining scopes saves on permits, mobilization, and the general conditions that apply to any construction project.
Cost Drivers Specific to Each Option
Addition Cost Drivers
- Foundation work: New additions need foundations, which vary by soil conditions and local seismic requirements
- Structural tying: Connecting new construction to an existing structure requires careful engineering
- Roofline integration: Matching rooflines between old and new sections affects both cost and aesthetics
- Setback compliance: Bay Area cities have strict setback requirements that limit where you can build
Remodel Cost Drivers
- Discovery: Opening walls in older homes reveals surprises (outdated wiring, plumbing, asbestos)
- Matching: New finishes need to blend with existing areas you are not remodeling
- Working around existing conditions: Remodeling is inherently less efficient than new construction because you adapt to what is there
How Custom Home Handles Both
Custom Home designs and builds both additions and remodels, and frequently combines them. Our two-phase process starts with a comprehensive design phase where we evaluate your existing structure, identify opportunities, and design the scope that delivers the most value for your budget.
Phase 1 is especially valuable when you are deciding between adding on and remodeling. We can show you both options in 3D with real pricing, so you make the decision based on facts rather than guesses.
What Should You Do?
The right choice depends on your specific home, lot, and goals. Start with a conversation about what is not working and what you want your home to become.
Schedule a free consultation to discuss your project with the Custom Home team.
Frequently Asked Questions
Does an addition or remodel add more value to my home?
Additions increase your home's square footage, which directly increases assessed value ($500-$1,000+ per sqft in the Bay Area). Remodels increase quality and livability, returning 50-80% of investment at resale. The best ROI often comes from a strategic combination of both.
Can I add a second story instead of building out?
Yes. Second-story additions are common in the Bay Area where lot sizes are limited. They cost 10-20% more than ground-floor additions due to structural reinforcement of the existing foundation and framing. Not all homes can support a second story without significant structural work.
Do I need to move out during construction?
For a remodel confined to specific areas (kitchen, bathrooms), you can usually stay. For additions that require tying into your existing structure, construction disruption varies by phase. Second-story additions typically require relocation since the work happens directly above your living space.
What permits do I need for each option?
Both require building permits. Additions also need setback compliance review, and second-story additions may trigger design review in cities like Palo Alto, Los Gatos, and Saratoga. Remodels that do not change the building footprint have simpler permitting.