Closing Up the Beach House: A Lowcountry Checklist

Closing up a Lowcountry second home for the off-season comes down to four things: humidity, pests, salt air, and the tail end of hurricane season. Keep the HVAC running to hold moisture down, shut off the water, close the supply lines that leak quietly, and arrange for someone local to walk the house on a schedule.

Last updated: October 2026

The national winterizing checklists you'll find in a search are built around frozen pipes, antifreeze in the drain traps, and draining the system before the first hard freeze. On Hilton Head Island and in Bluffton, a hard freeze is a rare night or two. The house you lock up in October will sit through warm, damp weeks, a few cold fronts, and a hurricane season that officially runs until November 30. Plan for that house.

Quick Facts

• Main risk for a closed Lowcountry house: humidity and mildew, well ahead of freezing
• Atlantic hurricane season: officially runs through November 30
• HVAC: leave it on; keep indoor relative humidity at or below roughly 60 percent
• Water: main off, water heater off or on vacation mode, ice maker, washer, dishwasher and toilet supply valves closed
• Pests to plan for: palmetto bugs, rodents, wasps and mud daubers, termites
• Salt air: rinse and inspect the HVAC condenser, exterior fixtures, hinges and door tracks before you leave
• House checks: weekly or every other week, plus a visit after any named storm or major wind event
• Documented: October 9, 2026 (this guide is reviewed and updated in place each fall)
• Validation: checked against the published end of the Atlantic hurricane season (NOAA) and resident practice on Hilton Head Island and in Bluffton

The Systems Pass: HVAC, Water, and the Lines That Leak Quietly

Keep the HVAC on and set it for humidity

Shutting the air off to save on the power bill is one of the costliest mistakes a coastal owner can make. A closed house with no air moving can grow mildew in a few weeks, especially through October, which down here usually feels like an extension of summer. Leave the system on. A cooling set-point in the high 70s keeps the house dry through the warm stretches, and a heat floor somewhere in the mid-50s to low 60s covers the handful of genuinely cold nights. If your thermostat has a dehumidify mode or reports indoor humidity, use it. The number residents watch is roughly 60 percent relative humidity or lower.

Before you leave, have your HVAC company flush and treat the condensate drain line. Lowcountry humidity grows algae in those lines, and a clogged line in an empty house tends to announce itself as a water stain on the ceiling below the air handler, usually weeks after it started. Ask them to confirm the float switch works, so a backup shuts the system off before the pan overflows. Swap the filter on the way out too.

Water off, then the small valves

Close the main shutoff, then open a low faucet to bleed the pressure out of the lines. Turn the water heater off or set it to vacation mode. Then go after the supply lines behind the quiet leaks: the ice maker, the washing machine hoses, the dishwasher, and the toilet supplies. A braided hose that drips for six weeks does more damage than a burst pipe somebody catches the same afternoon.

Irrigation is often on its own meter. If yours is, leave it on a reduced schedule with a working rain sensor, and make sure the heads point away from the foundation and siding.

Refrigerator and electronics

Either empty the refrigerator, unplug it, clean the drip tray and prop the doors open, or leave it running with very little inside. A closed, unplugged refrigerator turns into a mold box by spring. Unplug televisions, chargers, and anything without a reason to be on, since late-season thunderstorms bring surges. Leave powered the things that protect the house: the HVAC, the thermostat, any dehumidifier, the security system, and the Wi-Fi that lets you see them from wherever you are.

The Humidity War: What October to March Does to a Closed Coastal House

Locals think about the off-season in phases. October and early November stay warm and wet, with the marsh putting dew on the windshield by morning. December through February brings cold fronts and bright, dry days, then runs of damp, gray weather off the ocean. By March the pine pollen arrives and coats screens, porches and pool decks yellow. A closed house sits through each of those stretches, and the moisture finds the same places in house after house.

Where mildew shows up first. Closets on exterior walls. The back of upholstered furniture pushed against an outside wall. Under bathroom and kitchen sinks. Mattresses, leather, and anything stored in plastic bins in the garage. Leave interior and closet doors open, crack the cabinet doors, pull furniture a few inches off exterior walls, and take towels, bath mats and shower curtains out of play. Moisture that can't move is moisture that grows.

What moves in when the house goes quiet. Palmetto bugs come up through dried-out drain traps and gaps around plumbing. Rodents look for warm attics once the nights cool. Wasps and mud daubers build under the eaves, inside grill covers, and in the folds of stored umbrellas. Keep your pest-control service on its regular schedule while you're away, and confirm your termite bond is current. Subterranean termites are a Lowcountry fact of life, and a lapsed bond is the wrong surprise to find in spring.

Salt air keeps working while you're gone. Exterior metal on a coastal house corrodes on its own clock. Before you leave, rinse the HVAC condenser, outdoor light fixtures, door hardware and sliding-door tracks with fresh water, and lubricate hinges and locks so they still open in March. Oceanfront and marsh-front homes see it fastest, and the condenser is the expensive one.

What residents check monthly. Indoor humidity on the thermostat. A look under each sink. A sniff test in the closets. The drip pan under the air handler. And a few seconds of running water at each faucet plus a flush of each toilet to refill the traps, which keeps both odors and insects out. With the main off, the house-watcher opens it for the visit and closes it again on the way out.

Read this alongside the Hilton Head hurricane prep checklist; the two overlap on shutters, outdoor furniture and documentation. For how water exposure ties into the bigger ownership picture on the coast, see how flood zones affect waterfront resale value.

The Out-of-State Owner's Arrangement

If you live somewhere else from November to spring, the part of closing up that matters more than any valve is the person who walks the house after you leave.

Who walks the house

A professional house-watch service, a property manager, or a trusted neighbor with a key. Whoever it is, confirm they're insured, that they have a key and the alarm code, and that your property owners association has their name on file. Some gated communities in the area ask for a contact on unoccupied homes, so check with yours before you go.

How often

Once a week or once every two weeks is the usual rhythm, plus a visit within a day or two of any named storm or major wind event. A short visit on a regular schedule catches a slow leak while it's still a towel and a plumber, before it becomes drywall and flooring.

What they photograph

Ask for time-stamped photos in a shared album at each visit, so you can scroll the season from your phone:

• The thermostat display, showing temperature and humidity
• Under each sink and around each toilet base
• The water heater pan and the air handler drip pan
• Ceilings below bathrooms and below the air handler
• Closet corners on exterior walls
• The exterior: roofline, gutters, downspouts, screens, and the dock or deck if there is one

That photo log also helps with an insurance claim. Pair it with a walkthrough video you shoot yourself on closing day. The post on oceanfront insurance and property value covers why documentation carries weight on the coast.

Storm-tail season

The calendar says hurricane season ends November 30, and late-season storms do reach this stretch of coast. Close up in early October and the house still has roughly eight weeks of exposure. Bring in or tie down outdoor furniture, store grills and cushions, decide whether shutters go up now or on a call, and make sure your house-watcher knows the plan and who to call for a downed tree, a roof problem or an extended power outage.

The Morning You Leave

1. Check the thermostat set-points and humidity mode, and confirm you can see them remotely.
2. Close the ice maker, washer, dishwasher and toilet supply valves.
3. Shut the water main and open a low faucet.
4. Turn the water heater off or to vacation mode.
5. Empty or reduce the refrigerator; prop the doors if it's unplugged.
6. Unplug electronics that don't need power.
7. Open closet and interior doors, crack the cabinets, and pull furniture off exterior walls.
8. Take out the trash and wipe down the kitchen; a crumb is an invitation.
9. Bring in or secure outdoor furniture, cushions and grills.
10. Lock up, set the alarm, and send your house-watcher a final photo of the thermostat.

Opening Back Up in Spring

Turn the water on slowly and walk the house listening for drips. Run each tap until it runs clear. Change the HVAC filter. Hose the pollen off the screens and porch. If the photo log stayed clean through the season, the house should open with nothing worse than a light dusting. For what's on around the island once you're back, the monthly events calendars are a good place to start, and if you're still weighing how a second home fits your plans, buying a second home on Hilton Head covers the ownership side.

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Thinking past the checklist?

If working through this has you thinking bigger-picture about your Lowcountry property — what it needs, what it's worth, whether this is the year — I'm happy to talk it through. No pressure, just a straight read from someone who lives here.

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Donna Gilmore · Licensed REALTOR® · COAST brokered by eXp Realty · SC License #SC119301

Donna Gilmore is Director of Operations at COAST brokered by eXp Realty and lives in the Lowcountry. More homeowner guides: Hilton Head hurricane prep checklist | Buying a second home on Hilton Head.