Cost to Bump-Out Addition in San Antonio, TX (2026)
If you’re budgeting a bump-out addition in San Antonio, most projects run $8,531-$42,653, 15% below the $22,000 national average. What moves that number most is usually one thing: Foundation Type. On its own it can swing the cost by $0 - $15,000, so that’s the decision to slow down on before you sweat the smaller stuff.
Easiest place to save: Keep the bump-out to 2 feet or less so it can cantilever off existing framing - this eliminates foundation costs entirely.
$8,531-$42,653 in San Antonio
15% below the national average · 0.85x cost multiplier
Expect to pay $8,531-$42,653 for a bump-out addition in San Antonio, about 15% below the national benchmark. The Southeast region's contractor market and material costs account for most of this difference. The detailed breakdown below shows how budget, mid-range, and premium projects compare at San Antonio prices.
Cost Breakdown in San Antonio
| Line Item | Low | Mid | High |
|---|---|---|---|
| Cost per sq ft | $77 | $136 | $213 |
| Materials | $3,780 | $8,033 | $17,010 |
| Labor | $4,524 | $8,294 | $16,589 |
| Permits | $1,134 | $1,890 | $2,835 |
| Design | $756 | $1,418 | $2,835 |
| Total | $10,194-15% vs. national avg | $19,635-15% vs. national avg | $39,269-15% vs. national avg |
Budget
Small 60-80 sq ft bump-out, cantilevered over existing foundation, no foundation work needed, standard materials matching existing siding.
Mid-Range
100-150 sq ft bump-out with foundation piers or slab extension, mid-grade finishes, energy-efficient windows, basic electrical.
Premium
200+ sq ft bump-out with full concrete foundation, premium materials, custom windows, dedicated heating/cooling, high-end finishes.
Material Options
Material prices below are national averages; availability in San Antonio may shift costs slightly.
| Material | Cost/Unit | Best For |
|---|---|---|
| Cantilevered (No New Foundation) | $90-$130 per sq ft | Small bathroom, closet, or bay window expansions of 2-3 feet depthLowest cost option, no excavation or foundation work, fastest construction |
| Concrete Pier Foundation | $110-$160 per sq ft | Bump-outs of 3-6 feet depth in moderate climatesGood for medium-sized bump-outs, minimal excavation, stable support |
| Poured Concrete Slab | $130-$190 per sq ft | Kitchen or family room bump-outs where a durable floor is neededSolid, stable, can support any size addition, good for kitchen/dining expansions |
| Full Perimeter Foundation | $160-$250 per sq ft | Large bump-outs over 150 sq ft or in areas with challenging soil conditionsMost stable, allows crawl space access, supports heavy loads and large bump-outs |
Other Projects in San Antonio
San Antonio Estimate
Typical Range
$8,531-$42,653
vs. National Average
15% below national
Cost Multiplier
0.85x
Cost Per sq ft
$77-$213
This 0.85x estimate prices San Antonio labor from BLS Occupational Employment and Wage Statistics (May 2025) and applies a lighter regional adjustment to materials and permits, which vary less by metro than labor does. Actual bids vary by contractor, project scope, and timing.
See national average costs →