Cost to Bump-Out Addition in Detroit, MI (2026)

If you’re budgeting a bump-out addition in Detroit, most projects run $9,695-$48,475, 3% 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.

$9,695-$48,475 in Detroit

3% below the national average · 0.97x cost multiplier

In Detroit, a bump-out addition runs $9,695 to $48,475 on average - about 3% below what homeowners pay nationwide. The Midwest market's labor costs account for most of the gap, with material pricing and local permitting fees adding to the spread. Use the cost table below to compare budget, mid-range, and premium options side by side.

Cost Breakdown in Detroit

Line ItemLowMidHigh
Cost per sq ft$87$155$242
Materials$3,700$7,863$16,650
Labor$6,105$11,192$22,384
Permits$1,110$1,850$2,775
Design$740$1,388$2,775
Total$11,655-3% vs. national avg$22,293-3% vs. national avg$44,584-3% 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 Detroit may shift costs slightly.

MaterialCost/UnitBest For
Cantilevered (No New Foundation)$90-$130 per sq ftSmall 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 ftBump-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 ftKitchen 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 ftLarge 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 Detroit

Detroit Estimate

Typical Range

$9,695-$48,475

vs. National Average

3% below national

Cost Multiplier

0.97x

Cost Per sq ft

$87-$242

This 0.97x estimate prices Detroit 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 →