Renovate or add on to your house

Three things to know before you plan.

• In a flood zone, work that costs half the house's value can mean raising the whole house.
• We plan the work around the rooms you still need, like the kitchen and bath.
• Smaller jobs, like a bath or a screened porch, are welcome too.

Additions and outdoor rooms

Interior remodels

Coastal envelope and resilience

Turning a garage into an apartment, or adding an in-law suite? Those are on our page about accessory dwelling units. Paint, new flooring or a cabinet swap on its own is a different kind of job, and capable people in this market do them well. The high-performance page goes deeper on damp and the building shell.

What counts

The test weighs the cost of the work against the market value of the building alone. The land is left out, and the value is taken before the work starts. Repairs, rebuilding, rehab and additions all count, added together. A house with that much storm damage is measured the same way. Topsail Beach lets the value come from an appraisal, the depreciated replacement cost or the adjusted tax value. The figure used can put the same job on either side of the line.

How long the count runs

Most towns that publish a window count the work over any one-year period. They include Wrightsville Beach, Kure Beach, Ocean Isle Beach, Topsail Beach and Southport, where the costs add up. Carolina Beach draws its line at 49 percent. New Hanover County counts over five years. Its rule covers Porters Neck and the county's other unincorporated land. In Burgaw, the count also runs across any five years. Pender County and Atkinson both count over one year. Holden Beach counts over any two years. In Wilmington, repairs from the five years before the job are added to its cost.

What crossing it means

Past the line, a renovation becomes an elevation project. The house has to be raised to the same flood protection elevation a new house would need, freeboard included. Freeboard is extra height a town adds above base flood elevation, the flood height the map sets. On Holden Beach, a pre-FIRM cottage on the second row reaches the line fast once a kitchen, a bath and a roof share one job. In Wilmington, the same question can turn a kitchen-and-baths job into a talk about raising the whole house.

Outside the flood zone

Outside a mapped flood zone, North Carolina's residential code holds new work to today's rules. Unless the code says otherwise, the rest of the house can stay as built. Section R102.7.1 holds additions, alterations and repairs to the rules for new construction. The existing house does not have to comply, as long as the work does not make it unsafe or hurt how it performs. The energy chapter adds a percentage of its own. Say a project over $10,000 turns unconditioned space into conditioned space, like an enclosed porch or a finished garage. It puts 10 percent of its cost toward meeting the energy code (Section N1109.2).

An addition also counts toward the 50 percent rule, along with everything else done in the same window. On an older coastal home, that can bring rules for the whole house into a job meant for the new space. We find that early. We confirm it with the local floodplain administrator before design commits you to anything.

Creek and river lots

Near some creeks and rivers, the flood rules set their own setback. It applies where a stream is mapped approximate Zone A: a flood zone drawn with no base flood elevation. There, New Hanover County and Pender County bar fill, new building and substantial improvement within 20 feet of the top of the bank. If five times the width of the stream is greater, that distance applies. The exception is a registered engineer who certifies the work will not raise flood levels. The rule reaches river and creek lots in Castle Hayne, Myrtle Grove, Maple Hill and Currie.

Finding it early costs a phone call. Finding it at permit costs a redesign.

Island cottages

On Oak Island, much of the housing is the low, one-story cottage built fast after Hurricane Hazel in 1954. Whether a lot is pre-FIRM still depends on where it sat before the 1999 merger: Long Beach, Yaupon Beach or unincorporated Brunswick County. Kure Beach counts a building begun before January 6, 1982, its first flood map date, as an existing structure. On Ocean Isle Beach, older canal cottages can be renovated. Work worth half the building's market value within a year crosses the line.

Historic districts

In Southport, exterior work in the local historic district needs a certificate of appropriateness. It comes from the Historic Preservation Commission, before a building permit. For a historic building in the floodplain, the Board of Adjustment may grant a variance for repair or rehab that keeps its designation. In Wilmington, work you can see from the street in a local district or overlay goes to the Historic Preservation Commission first. Wrightsville Beach designates individual landmarks. A designated building can get its own exception from the 50 percent test by variance.

Inland bungalows and farmhouses

In Burgaw, a 1920s bungalow or a 1960s brick ranch is worth renovating first. A house that contributes to the National Register district can fall outside the 50 percent rule by variance. One project that comes up in Winnabow is renovating or replacing an older farmhouse or ranch. On an Atkinson home place, the well and septic system, sometimes decades old, set real limits on where anything new can go.

Say that in August the house smells faintly of damp. One room runs four degrees warm, and nobody uses it. The system runs almost nonstop, and the power bill makes no sense. Three people have looked at it and given you three answers.

A quote for that one room leaves all of it in place. Coastal houses fail as systems. The envelope is the walls, roof, floor, windows and doors that keep the weather out. Envelope, moisture, air movement and heating and cooling load are one problem wearing four faces. Pricing a job before finding the cause is how renovations go over budget and still disappoint. Our note on planning for moisture before it appears goes further into the envelope side.

What the assessment covers

We look at the structure, the envelope and the mechanical systems together. Code and flood exposure and the limits of the site go on the record too. Every project gets a written record of the house as it stands, what the structure can carry, and the permit path. How far the performance work goes past that is a choice we make with you. Design then works from that record, with cost estimates kept current so the drawings stay inside your budget.

When air leaks are part of the problem, we set an airtightness target in ACH50. ACH50 counts how many times the air in the house is replaced in an hour at a set test pressure. Lower means tighter. A blower-door test checks the house against the target.

We assess before we price.