Partial second story
$150k–$275k
- Engineer's structural review
- Roof removed over one section only
- New stair from the main floor
- One or two bedrooms or a suite
- Heat and cooling for the new rooms
- Exterior matched to the house
Second story additions · Licensed & insured · NARI member
A second story addition that starts with an engineer,
not a guess about your foundation.
Before any price, a structural engineer checks whether your footings and walls can carry a new floor. Then a licensed supervisor sends three written options within 24 hours: a partial second story from about $150,000, a full new floor, or a full floor with the main level reworked.
Text a photo of the front of the house and its approximate square footage. You hear back from a supervisor, not an operator, inside 5 minutes on business days.
- $300–$500Per sq ft, typical
- 6–9 moFull new floor
- 4.9410 reviews
- 24hWritten estimate
What happens after you text us
A supervisor asks about your foundation first. Then about the floor plan.
A second story lives or dies on what is under the house. The first exchange covers the foundation type, the age of the house and whether you want to stay in it, then sets a joint visit with the structural engineer.
- The engineer and supervisor visit together, once
- Foundation type and house age decide most of the price
- Live-in or move-out plan discussed before the estimate
Hi, we have a three-bedroom ranch on a crawlspace and two teenagers. We want to add bedrooms upstairs instead of losing the back yard.
Hi Lisa, this is Greg, I run second story builds for ProBuild Remodeling. Crawlspace ranches are often good candidates. Could you send a photo of the front and one from inside the crawlspace hatch, just pointing at the footing?
Sent. My husband wants to know if we have to move out.
Fair question. When we remove the whole roof, most families move out for 8 to 12 weeks. If we can keep part of the roof, you might stay. The engineer and I can come Wednesday at 4 and answer both questions on site.
Wednesday works. Will you know that day if the house can take it?
We will have a first read that day and the engineer's letter within a week, with your three-option estimate right after. See you Wednesday.
What a second story costs
A second story addition costs $150,000 to $750,000. The structure below decides where you land.
Prices assume a sound foundation, mid-range finishes and a new staircase. Reinforcing footings, adding steel beams or rerouting ductwork through the first floor is priced in the estimate after the engineer's review, not discovered later.
Full second story
$275k–$500k
- Whole roof removed and rebuilt
- Footings or walls reinforced
- Three to four rooms and a bath
- New stair and upstairs hallway
- Second HVAC zone or new system
- New roof, siding and gutters
Second story and rework
$450k–$750k+
- Everything in Full second story
- Main-floor walls moved or opened
- Steel or engineered beams
- Two or more new bathrooms
- Electrical service upgrade
- Kitchen or living area refit
Price your second story in ten seconds
Choose how much of the house you build over, the size of the footprint and the age of the house. The range updates with each choice, from the same three options our supervisors write up.
A range, not a quote. Your written estimate comes after the visit and does not change once you approve it.
Typical range for your answers
Turn this range into a written second story estimateWhere the money goes
A fifth of the budget is structure you never see. That is what keeps the house standing.
Averages from recent full second story builds. Engineering, reinforcement and a new roof are paid before a single bedroom is finished, which is why a quote that skips the structure line is not a real quote.
Get my itemized second story estimate
Stay in the house or move out
Stay home when part of the roof stays on. Move out when the whole roof comes off.
The single biggest lifestyle question in a second story is where you sleep for a few months. It depends on how much roof comes off and what happens downstairs. At the visit we check six things and put the answer in writing.
| If this is true | Plan to |
|---|---|
| The new floor covers only part of the house | Stay home |
| The entire roof is removed at once | Move out |
| The main floor stays untouched except the stair | Stay home |
| Main-floor walls, kitchen or ceilings are rebuilt | Move out |
| The addition is built over the garage | Stay home |
| Someone at home has asthma or a newborn | Move out |
How long it takes
A full second story takes six to nine months, and the roof is open for days, not weeks.
A partial second story runs 5 to 7 months, one with main-floor rework 8 to 10. We schedule the tear-off in a dry forecast window and have the new floor sheathed and wrapped within about a week.
Before day one
Engineering and permit
Structural review, plans, engineer's stamp and permit. Six to ten weeks, with your move-out plan settled.
Weeks one to three
Reinforce and tear off
Footings or posts reinforced below, then the roof comes off section by section in a dry window.
Weeks four to twelve
Frame and dry-in
New floor deck, walls and roof framed, windows set and wrapped. The house is weathertight again early.
Final months
Systems and finish
Stair opened, ducts and wiring run, drywall, floors, bathrooms and paint, then inspection and walkthrough.
Before and after
Three houses that went up, without giving up a foot of yard.
What your new floor stands on
The structure is named in writing, beam by beam.
Two second story quotes can differ by six figures because one includes the structural work and one does not. Ours names every beam, joist and connector the engineer specified, so you know what is carrying your family.
Engineered floor joists
I-joists from Weyerhaeuser TJI or LP SolidStart that span farther than lumber and do not squeak, so the new floor feels solid.
LVL and steel beams
Laminated veneer lumber or steel beams where walls below are removed or loads are heavy, sized and stamped by the engineer.
Hurricane ties and hold-downs
Simpson Strong-Tie connectors from roof to foundation, so a taller house resists wind and uplift the way code now requires.
Roof trusses
Factory-built trusses delivered to the site and set by crane in a day, which shortens the time the house is open to weather.
Staircase
A code-compliant stair with 36-inch width, handrail and even risers, in oak or paint-grade treads to match your floors.
Zoned HVAC
A second heat pump or a zoned system with dampers from Carrier or Trane, with a thermostat upstairs that controls upstairs.
Written into every contract
Six promises you can hold us to.
The approved price is the final price. Change orders only with your written approval.
A credit for every working day of delay we cause. Weather and inspections excepted, in writing.
Dust barriers, floor protection and a clean-up before we leave. Your home stays livable.
A text or email every working day with photos and tomorrow's plan, or the day is free.
Workmanship warranty in writing, transferable to the next owner, backed by a fixed address.
A small deposit, then you pay only for work that is already completed, inspected and photographed.
Who is on your roof
A supervisor and an engineer, with you from the first visit to the final inspection.
A second story is a structural project first and a remodel second. You meet the people responsible for both before the roof comes off, and they are the ones who sign off at the end.
Second story supervisor
Runs the build, the tear-off window and your daily updates.
Structural engineer
Reviews the foundation, specifies beams, inspects the framing.
Framing lead
Builds the new floor deck, walls and roof to the stamped plan.
Recent second stories, with the real numbers
Three houses that went up, each finished on its contract date.
Ranch, full second floor
- Final price
- $412,000
- Duration
- 8 months
- Location
- City, ST
Suite over the garage
- Final price
- $198,500
- Duration
- 6 months
- Location
- City, ST
Bungalow, floor and rework
- Final price
- $587,000
- Duration
- 10 months
- Location
- City, ST
Your house is not average
Every house carries weight differently. Here is how your case changes the plan.
Each second story starts from the same three options, then changes with the structure, the neighborhood and the family living under it. Pick the case that sounds like yours.
An older house
Older homes often sit on shallow footings with undersized joists and wiring that stops at the attic. The engineer's review puts a price on each fix before you sign, so the structure never becomes the surprise in month three.
Assess my older house for a second storyA small lot with no yard
On a tight city lot, up is the only direction left. We check the height limit and floor-area ratio before any drawing, then plan the crane, the dumpster and material deliveries around the street and the neighbors.
Check the height limit on my lotKids who need their own rooms
Bedrooms upstairs and living space downstairs is the most common reason families go up. We plan the rooms, a shared bath and the laundry close together, and schedule the loudest work around the school year.
Price bedrooms upstairs for my kidsLiving in the house through it
When part of the roof can stay on, many families stay home. We seal the stair opening until the very end, keep one bathroom running and give you a week-by-week list of which rooms are usable and when.
Plan a second story while we live hereGoing up on a budget
A partial second story over the garage or one wing costs far less than a full floor because less roof comes off. We show how much space each option gives per dollar, so you can choose with the numbers side by side.
Compare partial and full second storiesHeight limits and neighbors
Some towns cap height or require a hearing when a house goes up. We prepare the drawings and shadow studies the board asks for, and talk to the neighbors before the first delivery truck blocks the street.
Get my second story through zoningA hot summer climate
Upstairs rooms in a hot climate overheat unless the roof and ducts are planned for it. We specify radiant barrier sheathing, sealed ducts inside the insulation and a system sized for the new floor, not the old one.
Price a second story built for heatAdding value before selling
A second floor turns a two-bedroom house into a four-bedroom one, which changes its comparable sales. We share cost per added bedroom and bathroom so you can check the math with your agent before committing.
Price the bedrooms a second story addsWhat this service is
A second story addition, defined the way we quote it.
Second story addition is the construction of a new floor of living space on top of an existing house, by removing all or part of the roof, reinforcing the structure below and framing new rooms above. ProBuild Remodeling performs it as a licensed general contractor with a structural engineer, under one contract, one permit and one supervisor.
The service covers partial second stories over one wing or a garage, full new floors over the whole footprint, and projects that also rework the main level. It includes engineering, foundation reinforcement, tear-off, framing, stairs, systems and finishes. Rooms built beside the house at ground level are a home addition, and finishing an existing attic is an attic conversion, each with its own page.
It is for homeowners on small or fully used lots who want more bedrooms without moving, and for families who plan to stay long enough for the investment to pay back. It is not for houses where the engineer finds the foundation cannot be reinforced at a sensible cost, or for owners who need the space within a few weeks.
The words you will see on your second story estimate
- Structural review
- An engineer's inspection of footings, walls and joists to confirm what the house can carry and what must be reinforced.
- Bearing wall
- A wall that carries weight from above down to the foundation. It cannot be removed without a beam in its place.
- Tear-off
- Removal of the existing roof so the new floor can be built. Scheduled in a dry forecast and covered the same day.
- Sistering
- Bolting a new joist alongside an old one so the pair can carry the load of a floor instead of only a ceiling.
- LVL beam
- Laminated veneer lumber: layers of wood glued into a beam that is stronger and straighter than sawn lumber of the same size.
- Floor-area ratio
- A zoning limit on total floor space compared with lot size. It can cap how large a second story is allowed to be.
- HVAC zone
- A part of the house with its own thermostat and airflow, so upstairs and downstairs can be kept at different temperatures.
- Engineer's stamp
- The licensed engineer's seal on the plans. Building departments require it before approving a second story permit.
Questions we hear on every second story call
The eight questions people ask before going up.
How much does it cost to add a second story to a house?
Most full second stories land between $275,000 and $500,000, or about $300 to $500 per square foot of new space. A partial floor over a garage or one wing starts near $150,000. Foundation work and main-floor changes push projects toward the top of the range.
Can my foundation support a second story?
Many can, some need reinforcement, and a few cannot at a reasonable cost. A structural engineer checks the footings, walls and soil before we price anything. If reinforcement is needed, it is a separate line in your estimate, not a surprise later.
Do we have to move out during a second story addition?
Usually yes when the entire roof comes off, typically for 8 to 12 weeks. With a partial second story or a floor over the garage, most families stay. We settle this before signing so you can plan housing and the budget for it.
How long does a second story addition take?
A partial second story takes 5 to 7 months of construction, a full new floor 6 to 9 months, and a floor with main-level rework 8 to 10. Engineering and permits add six to ten weeks before we start.
What happens if it rains while the roof is off?
We tear off in a dry forecast window, one section at a time, and cover the open deck with tarps every evening. Trusses are set by crane, so the house is usually dried in within about a week.
Where does the staircase go?
The stair usually takes 40 to 60 square feet from the main floor, often from a closet, hallway or part of a bedroom. The supervisor shows you two or three positions at the visit and how each one changes the upstairs layout.
Is a second story cheaper than building out?
Per square foot, going up usually costs more because of structure and tear-off. It wins when the lot has no room, when zoning limits lot coverage, or when you would rather keep the yard than save on the build.
Will my utility bills go up with a second floor?
Some, because there is more space to heat and cool. New walls and roof are insulated to current code and upstairs gets its own zone, so the added cost per square foot is usually lower than for the older floor below.
Second story additions near you
Your remodeling address, within our service area.
Height limits and engineering rules vary by town. Every second story is built by a local crew under the license of its state, with an engineer licensed there.
- Maine
- New Hampshire
- Massachusetts
- Rhode Island
- Connecticut
- New York
- New Jersey
- Pennsylvania
- Delaware
- Maryland
- Virginia
- North Carolina
- South Carolina
- Georgia
- Florida
- Check your remodeling address
Free second story estimate
Send your answers now. Get an engineer's visit and three written options.
Your supervisor reads the answers, texts back within 5 minutes during business hours and books the joint visit with the structural engineer in the same conversation.