Can my house hold a second story?

Often, with some work below. An engineer checks the footings, the first-floor walls and the ties that hold the roof down. The design then says what each part needs to carry two stories. Some houses need little added. Others need new footings beside the old ones, or new sheathing on the first-floor walls.

Do I need an engineer for a second-story addition?

Here, yes. Every lot in Brunswick, New Hanover and Pender Counties has a design wind speed of 130 mph or more. At that speed, North Carolina's residential code sends the design to one of its high-wind methods (Section R301.2.1.1). Outside walls are designed by accepted engineering practice (Section R4505.1). So the new story and the house under it are engineered together.

Will my footings have to be widened?

Only where the engineer's design calls for it. The code sizes a footing by the stories it carries and the soil it sits on. In the 140 and 150 mph zones, it also calls for continuous concrete footings under the outside walls (Section R4503.1). Some footings carry a story as they are. Others get a new footing poured beside them.

How tall can I build?

As tall as your town allows, measured your town's way. Holden Beach allows 31 feet above its Design Flood Elevation. Oak Island allows 35 feet above the average grade at the four corners, or 41 in the VE zone. On a raised house, where your town measures from decides how much height is left. We look up the limit at your address before design.

Do I need a permit to add a second story?

Yes, at any cost. State law lets some work of $40,000 or less skip the building permit. That exemption ends where the work adds load-bearing framing, plumbing, wiring or roofing. A second story adds load-bearing framing, wiring and roofing, and often plumbing. In a local historic district in Southport or Wilmington, the certificate of appropriateness comes before the building permit.

Do upstairs bedrooms need special windows?

Each new bedroom needs a window or door big enough to escape through. Upstairs, that is usually a window with its sill low enough to reach from the floor. New windows also carry a wind rating that rises with the height of the roof. East of the Intracoastal Waterway, they need protection from wind-blown debris as well.

Will my septic system handle more bedrooms?

The county health department answers that first. The state sizes a septic system by its bedrooms, at least 120 gallons a day for each one. A second story that adds bedrooms goes to the health department before the building permit. A house on sewer skips that step.

Can you add a second story over part of the house?

Yes. A story can cover one wing, such as a bonus room over an attached garage. The engineer checks the walls and footings under that wing, the same as for a full story. Where the new wall rises beside the old roof, flashing turns water away from the wall. An apartment over a garage, with its own kitchen, is an accessory dwelling unit.

Second-Story Addition

Second-story additions on the North Carolina coast

We add a second floor to one-story houses on this coast, over the whole house or part of it. The house you have has to carry the new floor and hold it down in high wind. So an engineer designs it, from the new roof down to the old footings. We work in Brunswick, New Hanover and Pender Counties.

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What you get when you build up.

Your house carries the new floor.

An engineer checks your walls and footings, then designs the new floor to tie into them. Where the house below needs work, the design says what. Damage that only shows once the roof comes off is carried as an allowance in the price.

We check how tall you can build.

Each town caps height and measures it its own way. On a raised house, some of that height may be used already. We check the limit at your address before design.

We plan both floors together.

A new stair has to land somewhere downstairs. Where it lands changes the rooms around it, so the first floor is planned with the second.

A second story starts with the house under it.

Before anything is drawn, the assessment writes down the house as it stands. Its frame, its foundation and its systems go on the record, with the height limit and the permit path for your lot.

The assessment records what the structure can carry. For a second story, that is the first question, and the engineer's design answers it. How we approach additions explains where new work meets old.

Send the address. We'll look up your town's height limit, how it's measured, and the wind speed there.

The job, step by step

Assess the house

The frame, the foundation and the systems go on the record as they stand.

Check the town's limits

Height, setbacks and floor area at your address, and the permit path.

Design and engineer

The new floor is drawn, and the engineer designs its path down to the footings.

Strengthen below

Footings, walls and ties are added where the design calls for them.

Build up

The old roof comes off where the story goes. The new floor, walls and roof are framed and tied down.

Rough in and insulate

Wiring, pipes and ducts run upstairs, and the new walls and roof are insulated.

Inspect and finish

The work passes its final inspection, and the inspector issues a certificate of compliance.

What the old roof hides is an allowance.

Taking the roof off shows the top of the old walls and the ceiling framing under it. Damage that only shows then is carried as an allowance in the price.

The choices are yours.

How much of the house the story covers: all of it, or one wing such as the garage
The rooms upstairs, and how many are bedrooms
Where the stair lands downstairs
The shape of the new roof, within your town's height limit
Whether impact windows and doors downstairs join the job
Whether new siding on the first floor joins it too
A second heating and cooling system, or a new zone on the one you have
Whether to seal the new story to an airtightness target

Design is its own step, and you keep the drawings. Each decision goes into your private online workspace with the reason behind it.

A room over the garage builds up one wing.

A bonus room over an attached garage, for your own household, is built the same way, on the garage's walls and footings. An apartment over a garage, with its own kitchen, is an accessory dwelling unit. Space added on one floor is a room addition, and a new garage on its own is a garage addition.

An older house adds two checks.

Paid work that disturbs paint in a house built before 1978 falls under North Carolina's lead-safe renovation rules. Old ceiling texture, joint compound, and flooring and its adhesive can hold asbestos. On an older house, those materials are tested by an NC-accredited inspector before demolition.

Whether you stay home depends on the job.

That comes down to how much of the house the work reaches. On a large job, you may need to move out. On a smaller one, we may be able to finish the work while you live there. Which one yours is gets settled for each project. Living through a renovation covers how work is staged around you.

The house you have carries the floor you add.

The new story meets the code for a new house, and the old house can stay as built. The added weight must not make it unsafe. Every lot here sits in a design wind zone of 130 mph or more, so showing that is an engineer's job.

Code in force: The North Carolina Residential Code. The new story meets the rules for a new structure, and the work may not make the old house unsafe (Section R102.7.1)
Design wind speed: Brunswick and New Hanover: 140 mph west of US 17, 150 east of it. Pender: 130 mph, except Topsail Township, at 140 west of the Intracoastal Waterway and 150 east (Table R301.2(4))
How it is designed: At 130 mph and up, to one of the high-wind design methods the code lists (Section R301.2.1.1). Outside walls follow accepted engineering practice (Section R4505.1)
Tie-down: Unbroken from the roof to the footing at 140 and 150 mph, and to the foundation wall or pier at 130 (Section R4508.1)
Building permit: Needed at any cost, since a story adds load-bearing framing, wiring and roofing, and often plumbing (G.S. 160D-1110)

The new floor's weight travels down through the first-floor walls to the footings. A taller house also catches more wind, which pushes on the walls and pulls up on the roof. The engineer follows both paths to the ground and says what each part needs.

What the engineer checks

The footings, for two stories on the soil under them
The first-floor walls, whose framing and sheathing now brace two stories
The ties that hold the new roof down through both floors
Beams and posts under any new upstairs wall that carries weight

The code sizes a footing by the stories it carries and the soil it sits on. The footing under your house starts with the soil explains how.

What your house stands on sets the questions.

An inland ranch on a slab, a cottage on masonry piers and an island house on pilings each carry a story their own way. Some need little work below. Others need new footings beside the old ones, or new sheathing on the first-floor walls. What does yours stand on?

A house on pilings can go up too.

A raised house on pilings can take a second story, built to an engineer's design. The engineer checks the piles, and the code requires them braced once the house stands more than one story above them.

The roof is tied down to the ground.

Wind pulls up on a roof, and a chain of ties carries that pull down through both stories. At 140 and 150 mph, the code runs that chain unbroken from the roof to the footing. The old walls become links in it.

Higher windows face more wind.

The wind pressure a window has to hold rises with the height of the roof. So the new upstairs windows are rated for the taller house. East of the Intracoastal Waterway, they also need protection from wind-blown debris. Impact windows and doors covers both.

A story over one wing meets the old roof.

A story over part of the house, such as a garage wing, rises beside the old roof. Where the new wall meets that roof, flashing turns water away from the wall and onto the roof. Where the roof's lower edge meets the wall, one more piece sends water clear of the siding (Section R903.2.1). Moisture management explains why the order of the layers matters.

When the house below would need rebuilding to carry a story, building new can make more sense.

Your town decides how tall the house can go.

Every town here caps building height, and each measures it from its own starting point. On a raised house, that starting point decides how much height is left for a second story.

Holden Beach: 31 feet, measured from the Design Flood Elevation (the base flood elevation plus two feet). In an X zone, 35 feet from finished grade
Ocean Isle Beach: In R-1, 31 feet from the bottom of the lowest horizontal structural member, and two stories of living area
Caswell Beach: Two stories, and the higher of 26 feet above the regulatory flood elevation or 35 feet above the mean elevation
Oak Island: 35 feet from the average finished grade at the four corners; 41 feet in the VE zone
Kure Beach: 35 feet from the mean finished grade. For a renovation, it may be measured from the top of the slab at the front entry
New Hanover County (outside its towns): 40 feet; 44 feet on an open foundation of piers, posts, columns or piles

Most towns measure from the ground. Oak Island uses the average finished grade at the four corners. Wilmington uses the average undisturbed grade at the foundation. On a house raised on pilings or a tall foundation, the climb to the first floor counts against the limit before the second story starts.

Holden Beach measures from its flood elevation. In its R-1 district, Ocean Isle Beach measures from the bottom of the lowest beam, so the height below it stays out of the count. Caswell Beach allows whichever of its two measures comes out higher. How much of that height does your house use now?

Some rules give a raised house room back. Unincorporated New Hanover County, around Masonboro and Ogden, allows 44 feet on an open foundation of piers, posts, columns or piles, against 40 on others. Kure Beach lets a renovation measure from the top of the slab at the front entry. Wilmington measures a pitched roof to a point halfway between its peak and its eave.

A new floor adds floor area.

A second story adds a whole floor of area, and some towns tie their rules to it. In Holden Beach's R-1 district, the setbacks deepen once a house reaches 4,000 square feet, and again at 5,000. The lot coverage limit tightens with them, and no house there may pass 6,000 square feet. In Ocean Isle Beach's R-1 district, the floor area above flood level is capped at half the lot.

An older house close to a lot line

Some older houses sit closer to a lot line than today's zoning allows. Pender County, Hampstead included, bars enlarging such a house in a way that makes the setback problem worse. So does Wilmington. Whether a story can go up over those walls is the town's call.

A historic district reviews the new size.

A historic district reviews the outside of a house, including its size and scale. In Southport's local historic district, that review comes before the building permit. In Wilmington, exterior work in a local historic district goes to the Historic Preservation Commission first. So does work seen from the street in a historic overlay. Older houses on our renovation page goes further.

The flood rule counts the story too.

In a mapped flood zone, the story counts toward your town's flood rule, with any other work done in the town's window. Past the line, the whole house has to meet the flood height for a new house, old floor included. FEMA's guidance says the same for a second story.

Bedrooms upstairs bring a few rules with them.

A second story often holds bedrooms and a bath. Each new bedroom needs a way out and a smoke alarm. On a septic lot, it also changes what the system has to carry.

The stair shapes the first floor.

A stair needs a run of floor downstairs, headroom over every step, and a floor or landing at the top and bottom. That space usually comes out of a hall, a closet or part of a room. So where the stair lands shapes the first floor as much as the second.

Every new bedroom needs a way out.

Each new bedroom needs a window or door big enough to escape through in an emergency (Section R310.5). Upstairs, that is usually a window you can climb out of, with its sill low enough to reach from the floor.

The alarm rules reach the whole house.

A permitted addition brings the smoke alarms in the whole house up to the rules for a new house (Section R314.2.2). That means one in each bedroom, one outside each sleeping area and one on every floor. Carbon monoxide alarms follow the same rule (Section R315.2.2). They are needed where the house has a fuel-burning appliance or fireplace, or an attached garage that opens into it.

Septic lots and new bedrooms

Where there is no sewer, as on many lots around Winnabow and Boiling Spring Lakes, the state sizes a septic system by its bedrooms. A second story that adds bedrooms goes to the county health department before the building permit. A house on sewer skips that step.

A bigger house needs its heating and cooling checked.

A second story changes the heating and cooling load for the whole house. The code sizes new equipment from a load calculation (Section M1401.3). If the new floor runs off the old ducts, the old system is evaluated for the new design. Right-sized systems explains why size matters on a humid coast.

The new story meets the energy code.

The new walls, roof, ducts and lights meet the energy code as a new house would (Section N1108.1). The rest of the house can stay as built. New wiring meets the North Carolina Electrical Code.

Questions about adding a second story

Can my house hold a second story?: Often, with some work below. An engineer checks the footings, the first-floor walls and the ties that hold the roof down. The design then says what each part needs to carry two stories. Some houses need little added. Others need new footings beside the old ones, or new sheathing on the first-floor walls.
Do I need an engineer for a second-story addition?: Here, yes. Every lot in Brunswick, New Hanover and Pender Counties has a design wind speed of 130 mph or more. At that speed, North Carolina's residential code sends the design to one of its high-wind methods (Section R301.2.1.1). Outside walls are designed by accepted engineering practice (Section R4505.1). So the new story and the house under it are engineered together.
Will my footings have to be widened?: Only where the engineer's design calls for it. The code sizes a footing by the stories it carries and the soil it sits on. In the 140 and 150 mph zones, it also calls for continuous concrete footings under the outside walls (Section R4503.1). Some footings carry a story as they are. Others get a new footing poured beside them.
How tall can I build?: As tall as your town allows, measured your town's way. Holden Beach allows 31 feet above its Design Flood Elevation. Oak Island allows 35 feet above the average grade at the four corners, or 41 in the VE zone. On a raised house, where your town measures from decides how much height is left. We look up the limit at your address before design.
Do I need a permit to add a second story?: Yes, at any cost. State law lets some work of $40,000 or less skip the building permit. That exemption ends where the work adds load-bearing framing, plumbing, wiring or roofing. A second story adds load-bearing framing, wiring and roofing, and often plumbing. In a local historic district in Southport or Wilmington, the certificate of appropriateness comes before the building permit.
Where will the stairs go?: Somewhere on the first floor, and picking the spot is an early design decision. A stair needs a run of floor, headroom over every step and a floor or landing at the top and bottom. That space usually comes from a hall, a closet or part of a room. So the stair is planned with both floors at once.
Do upstairs bedrooms need special windows?: Each new bedroom needs a window or door big enough to escape through. Upstairs, that is usually a window with its sill low enough to reach from the floor. New windows also carry a wind rating that rises with the height of the roof. East of the Intracoastal Waterway, they need protection from wind-blown debris as well.
Will my septic system handle more bedrooms?: The county health department answers that first. The state sizes a septic system by its bedrooms, at least 120 gallons a day for each one. A second story that adds bedrooms goes to the health department before the building permit. A house on sewer skips that step.
Will I need a new heating and cooling system?: A load calculation decides. The code sizes equipment from the heating and cooling load of the house as it will be (Section M1401.3). If the new floor runs off the old ducts, the old system is evaluated for the new design. A second system, or a new zone on the old one, is a design choice you make with us.
Can we live in the house while the second story goes on?: It depends on the extent of the work. On a large job, you may need to move out. On a smaller one, we may be able to finish the work while you live there. Which one yours is gets settled for each project, by how much of the house the work reaches.
Can you add a second story over part of the house?: Yes. A story can cover one wing, such as a bonus room over an attached garage. The engineer checks the walls and footings under that wing, the same as for a full story. Where the new wall rises beside the old roof, flashing turns water away from the wall. An apartment over a garage, with its own kitchen, is an accessory dwelling unit.

More renovation projects.

Renovation & Additions

Every kind of renovation and addition we take on, and how we assess the house first.

Explore

Room Additions

New space on one floor, tied into the old frame, roof and foundation.

Explore

Impact Windows and Doors

Openings replaced with impact-rated units, on the islands and off them.

Explore

Whole-House Renovation

Layout, systems, walls and finish, planned as one job.

Explore

References

Regulatory figures on this page summarize the town and county codes each linked city page cites, and the public sources below. Ordinances change; the parcel and the current adopted code decide, and the site analysis confirms both for your lot.

Build up on the house you have.

Tell us where the house is and what you want upstairs. We'll start with the height limit, the wind speed and the permit path at that address.

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