Closing a Cape Cod home for winter is not a casual weekend errand. Do it wrong and you will come back in April to a burst pipe, a mouse-shredded kitchen drawer, or an insurance adjuster explaining why your claim is complicated because the heat was set to "off." I have walked through this process on dozens of Cape homes — cottages in Truro, year-round capes in Brewster, shingled colonials in Chatham — and the same failures repeat every season. This guide covers every one of them, in the order that matters.
The Cape's maritime climate creates a specific winterization problem: temperatures routinely cycle through freeze-thaw dozens of times between November and March. A house does not need to hit -10°F to freeze pipes. A sustained night in the mid-teens with no heat and a west wind off the Bay will do it. Plan accordingly.
Plumbing: The Number-One Failure Mode
A single frozen-and-burst pipe in an unoccupied house is a $20,000–$80,000 loss by the time water damage, mold remediation, and repair are tallied. Insurance will cover it — eventually, conditionally — but the disruption to your summer season is unrecoverable. Prevent it completely with a proper drain-down.
Drain All Supply Lines
- Shut off the main water supply at the street-side shutoff (typically the ball valve near your meter or your basement wall).
- Open every faucet in the house — hot and cold — starting from the highest floor and working down. Leave them open until water stops running.
- Open the lowest drain point in the system (usually a boiler drain valve or hose bib at the base of the supply line) to clear residual water.
- Tag the shutoff valve with a piece of tape or a twist-tie label reading "CLOSED FOR WINTER." Contractors and property managers have found main valves left open by well-meaning neighbors who "just ran the water for a minute."
Blow Out with Compressed Air
After draining by gravity, residual water stays trapped in low spots and horizontal runs. Rent or borrow a compressor and blow each fixture from the supply end. This step is what separates a proper winterization from a guesswork drain-down.
Add Non-Toxic RV Antifreeze
Purchase non-toxic RV/marine antifreeze (pink — propylene glycol). This is not automotive antifreeze. Automotive antifreeze (ethylene glycol) is toxic, damages septic systems, and is illegal to introduce into a residential drain on a septic system under Massachusetts Title 5. Non-toxic RV antifreeze is rated to -50°F and is safe for drains.
Pour it into:
- Every P-trap under every sink and in every shower/tub drain
- Every toilet bowl (flush out remaining water first, then pour directly into the bowl)
- The toilet tank (pour into the tank after flushing)
The traps in floor drains in basements and utility rooms are commonly missed. Check them all.
Well and Pressure System
If your property is on a private well — which describes the majority of homes in Wellfleet, Truro, Eastham, and much of Brewster and Orleans — the sequence is different and more consequential:
- Shut off the well pump at the circuit breaker, not just at a pressure switch. The pump itself should be de-energized.
- Drain the pressure tank. Most residential bladder tanks have a drain valve at the bottom; open it fully. Leaving pressurized water in the tank through a Cape winter risks waterlogged tanks and failed pressure switches.
- If your pump is a submersible (in the well casing) versus a jet pump (in the basement), the pump itself does not need to be removed. The above-ground plumbing is what freezes.
Water Heater
If the property will be vacant all winter, drain the water heater completely. Attach a hose to the drain valve at the base and run it to a floor drain or outside. Turn the tank to "pilot" or shut off the circuit breaker before draining — running a water heater dry destroys the element.
If you plan to return before spring, set it to "vacation" mode (roughly 55°F) rather than draining it. Either is acceptable. Empty and cold is better if you won't return until May.
Hot Tubs and Pools
These require separate winterization and are beyond the scope of a DIY checklist for most homeowners. A licensed pool company will blow out the lines, add pool-grade antifreeze, install a safety cover, and drop the water level below the return jets. In Barnstable, Chatham, and Falmouth — where pool ownership is more common — this is a $200–$400 service worth every dollar.
Heat: The Second-Biggest Risk
Never Turn the Heat Off
Set your thermostat to 55°F minimum. Not 50°F. Not "off." The reasoning is simple: a Cape Cod house with no heat will reach ambient outdoor temperature within 12–18 hours. The first sub-20°F night — which typically arrives in December on the Outer Cape and January on the Upper Cape, though either can come earlier — will freeze any water left in the system.
Fifty-five degrees is the floor because it keeps interior temperatures high enough to compensate for a cold wall cavity or uninsulated pipe run in a drafty 1960s Cape. Some properties with poor insulation in rim joists or crawlspaces need 58°F.
Smart Thermostats and Remote Monitoring
For any second-home owner who cannot be at the property within two hours, a smart thermostat with freeze-alert capability is now essential, not optional. Options like the Ecobee or Honeywell T6 Pro can send you a text or email if indoor temperature drops below a set threshold. Pair it with a cellular backup communicator if your property is on a septic-only lot without reliable Wi-Fi during winter.
The Cape Cod Commission's records on winter storm damage consistently show that heating system failures go undetected for 48–72 hours in unoccupied second homes. That window is the difference between a service call and a gut renovation.
Mass Save Home Energy Assessment
The Mass Save Home Energy Assessment is a free, state-subsidized program available to all Massachusetts homeowners through Cape Light Compact (the Cape's regional energy provider). A certified energy auditor will walk your property and identify where heat is escaping fastest — typically rim joists, attic bypasses, and around recessed lights in older capes. The audit is at no cost, and rebates for air sealing and insulation can reach 75–100% of project costs for qualifying improvements.
Schedule it in September or early October, before closing season. Book at masssave.com or through Cape Light Compact directly.
Backup Heat Planning
If your heating system is oil-fired (which describes a large portion of homes in Brewster, Orleans, Chatham, and the Outer Cape towns), ensure your tank is full before closing — not half-full. A 275-gallon tank that runs dry at 2 a.m. on a January night guarantees a freeze-up if your plumber cannot get there before morning.
Consider adding one plug-in electric space heater on a thermostat in the utility room or mechanical space where pipes are most exposed. This is not your primary heat source — it is insurance against a boiler failure.
Exterior
Hose bibs burst first. Turn off and drain every exterior hose bib before any hard freeze. Most Cape homes have a separate shutoff inside the basement wall for each bib; close it, then open the bib outside to let any residual water drain. Disconnect and store hoses indoors — a frozen hose left on a bib will back-freeze into the wall.
Gutters and roof are a paired problem on the Cape. Pitch pines drop needles through November; oaks hold their leaves into December. A gutter full of debris in December becomes an ice dam in January. Ice dams form when heat escaping through the roof melts snow at the ridge, and refreezes at the cold overhang. The resulting ice lifts shingles and forces meltwater back under the roofing into the wall cavity. The repair — roofing, sheathing, insulation, drywall — routinely runs $8,000–$25,000.
Clean gutters in late October after leaf drop. Trim any overhanging tree limbs while you are at it — wet snow loads on Cape Cod can reach 20 lbs per square foot, and a limb over your roof is a structural risk.
Remove or cover window air conditioning units. An AC left in a window all winter is both a heat loss and a potential security vulnerability.
Interior
- Unplug all small appliances (toasters, coffee makers, phone chargers). An unoccupied house cannot self-correct an electrical fault.
- Clean the refrigerator thoroughly, prop both doors open, and leave it running on its lowest setting — or unplug it with doors propped open if you prefer. A sealed, humid refrigerator grows mold by March.
- Empty all pantry food — not just what might spoil. Mice eat through cardboard, foil, and thin plastic. Sealed glass or hard plastic containers are the only reliable alternative to empty shelves.
- Set light timers on two or three lamps visible from the street. The Cape's off-season break-in rate spikes after Columbus Day; occupied-looking homes are passed over.
- Test smoke and CO detectors and replace batteries. If your heating system malfunctions, carbon monoxide in a sealed house is a life-safety risk for anyone who enters.
Critter-Proofing
Mice are the most common occupant of closed Cape Cod homes, and the most expensive to remediate. A single pair of mice will produce 40–60 offspring in a season. By the time you arrive in May, you can have a full infestation in every wall cavity and drawer.
Before you close:
- Walk the entire exterior and seal any gap larger than a dime. Mice need 1/4 inch. Common entry points: where pipes and conduits enter the foundation, gaps in the sill plate, dryer vents, and around the where the chimney meets the framing.
- Use steel wool packed into gaps, then caulk over it. Expanding foam alone is not sufficient — mice chew through it.
- Set snap traps (Victor-style) in the basement, under the kitchen sink, and in any utility or laundry area. Check and reset them on any winter visit. Do not use glue boards — they are inhumane, messy, and ineffective against larger mice.
- Do not use rodenticide (poison bait blocks) inside the house. A mouse that ingests poison typically dies in the wall cavity. The smell is severe and persists for months, and decomposing rodents attract other scavengers and secondary pests.
Deer ticks remain active through November and into December on warm Cape days. The black-legged tick responsible for Lyme disease does not die in a mild frost. Before doing any final yard work or inspection, wear treated clothing and do a full tick check before re-entering the house.
Documentation
Take a complete photo record of the property before leaving for the season:
- All meters (electric, gas, water) with readable numbers
- The exterior of the house from all four sides
- Any existing damage — a cracked step, a scraped corner, a soft spot in the decking — documented before winter so it is not disputed as new damage in spring
- The thermostat reading
- All shutoff valves in their closed position
Send your emergency contact list to a trusted neighbor or your property manager. Include your plumber, your heating contractor, and yourself. Give them a physical key or a door code. A neighbor who cannot get inside cannot stop a pipe that is running through a ceiling.
Printable Winter Closing Checklist
Plumbing
- Main water supply shut off
- All faucets opened and drained top-to-bottom
- Compressed air blown through all supply lines
- Non-toxic RV antifreeze in all P-traps, toilet bowls, and tanks
- Well pump breaker shut off (if on well)
- Pressure tank drained
- Water heater drained or set to vacation mode
- Shutoff valve tagged
- Pool/hot tub winterized by licensed contractor
Heat
- Thermostat set to 55°F minimum
- Smart thermostat freeze alert configured
- Heating oil tank full (if oil system)
- Backup space heater placed in utility/mechanical room
- Mass Save assessment scheduled or completed
Exterior
- All exterior hose bibs turned off and drained
- Garden hoses disconnected and stored
- Gutters cleaned of leaves and debris
- Overhanging tree limbs trimmed
- Window AC units removed or covered
- Roof visually inspected for missing shingles or damaged flashing
Interior
- All small appliances unplugged
- Refrigerator cleaned and doors propped open
- All food removed from pantry and cabinets
- Light timers set on two or more lamps
- Smoke and CO detector batteries replaced
- All interior drains checked for RV antifreeze
Critter-Proofing
- Exterior gaps sealed with steel wool and caulk
- Snap traps set in basement, kitchen, and utility areas
- No rodenticide placed inside the house
- Dryer vent checked and sealed or screened
Documentation
- All meters photographed with readable numbers
- Exterior photographed from all four sides
- Existing damage documented with dated photos
- Emergency contact list and contractor numbers sent to neighbor or property manager
- Key or door code provided to trusted local contact
Frequently Asked Questions
Can I just turn the heat off and drain the pipes? Only if you do a complete, professional-grade drain-down including compressed air blowout and RV antifreeze in every trap. Most homeowners who say they drained the pipes missed at least one fixture. The cost of a plumber doing it properly — typically $150–$300 for a seasonal winterization — is cheap insurance against a burst pipe.
What temperature do I set my thermostat to if I'm leaving for the whole winter? 55°F is the industry standard minimum on Cape Cod. If your property has a crawlspace, uninsulated rim joists, or poorly insulated pipes in an attached garage, consider 58°F.
Is Cape Light Compact's Mass Save assessment really free? Yes. The Commonwealth of Massachusetts funds it through utility ratepayer charges. Cape Light Compact is the regional administrator. There is no catch and no sales pressure. The auditor will give you a written report. Rebates for air sealing and insulation are significant — call them at 800-797-6699 or visit capelightcompact.org.
Do I need to notify my insurance company that the home will be vacant? Check your policy language carefully. Many homeowner's insurance policies have a vacancy clause that limits or voids coverage after 30–60 consecutive days of vacancy. Inform your insurer before closing; some require a vacancy endorsement or a separate seasonal home policy. This is particularly important in Wellfleet, Truro, and Provincetown where seasonal vacancy is the norm and insurers are aware of the risk profile.
What do I do if I get a freeze alert from my smart thermostat in January? Call your property manager or a trusted local contact first — they can be on-site in minutes. Call your heating contractor second. Do not attempt to diagnose a heating system failure remotely. If the indoor temperature has already dropped below 45°F, assume pipes may freeze and treat it as an emergency response.
How do I find a reliable property manager or winterization contractor on the Cape? Ask for licensed, insured contractors with local references and verifiable HIC (Home Improvement Contractor) registration with the Massachusetts Office of Consumer Affairs. The Cape Cod Builder's Exchange maintains a contractor directory. Cape Cod Certified lists verified local contractors — see the links below.
Work With a Certified Local Contractor
Closing a Cape Cod home correctly takes about half a day if you know what you are doing and have the right tools. If you are doing it yourself for the first time, budget a full day and expect to find at least one thing you missed on the first pass.
If you would rather have a professional handle it — or if you want a licensed plumber to do the drain-down, a certified property manager to check on the house monthly, and a heating contractor who will actually pick up the phone in January — find them on the Cape Cod Certified directory.