Second Story Addition Cost Calculator
Price an upper-level addition with its main cost drivers visible: structural reinforcement, finished square footage, wet rooms, and exterior tie-in.
Your project scope
Addition area (sq ft)iAddition area (sq ft) Enter the planned sq ft amount. | |
|---|---|
Structural complexityiStructural complexity Opening an occupied roof and upgrading foundations or beams can dominate the budget. | |
Finish tieriFinish tier Interior finishes cover walls, flooring, doors, and typical electrical trim. | |
Bathroom countiBathroom count New stacks and supply routes are harder on upper floors. | |
Exterior match premiumiExterior match premium Matching older masonry, trim, and roofing can add specialized labor. | |
Your stateiYour state Scales U.S.-average labor and material midpoints for typical state-level pricing. It is not an on-site bid. |
How to use this calculator
- Enter the addition area (sq ft).
- Choose each scope driver to reflect your project.
- Select your state for cost scaling.
- Review the itemized components before requesting bids.
Results explained
This model uses separate construction components rather than a single blanket rate. The band reflects common variation in access, design, and contractor pricing.
Quick reference: Second Story Addition Cost cost drivers
Installed U.S.-average midpoints before the selected state adjustment.
| Scope | Midpoint |
|---|---|
| Standard second story | $285/sq ft |
| Major structural rework | +$140/sq ft |
| One bathroom | $26,000 |
| Detailed exterior match | $35,000 |
These are planning midpoints, not a site inspection, engineering opinion, or contractor proposal.
How the estimate is built
A base finished addition is priced by area, and structural, bath, exterior, and permit components are separated before state scaling.
Example scenario
A 700 sq ft mid-finish addition with moderate structure, one bath, and exterior matching models near $310,000 at U.S. average.
FAQ
Can I stay in the house?
Many projects require temporary moves during roof opening and major utility interruptions.
Is foundation work included?
The structural tier is a planning allowance; engineering may reveal more specific reinforcement.
Does this include HVAC?
The finished-space rate assumes typical extensions, but a new system or zoning can cost more.