Detached Garages, Sheds, and Docks: How Other Structures Coverage Works for Coastal SC Homeowners Insurance

What Is Other Structures Coverage — and Does It Cover Your Dock?

Other structures coverage (Coverage B) is the part of a standard homeowners insurance policy — most commonly the ISO HO-3 or HO-5 form — that protects structures on your property that are not attached to your main home, such as a detached garage, storage shed, fence, or private dock, up to a limit that is typically set as a percentage of your dwelling coverage.

That one sentence is the foundation. Now let’s unpack what it means for you as a Lowcountry homeowner, because the details matter — especially along the South Carolina coast where storms, saltwater, and tidal flooding put those outbuildings and docks to the test every single season.

Coverage terms, exclusions, and limits vary by carrier and policy form — always review your declarations page and policy documents, and ask a licensed GSP agent to confirm the specifics for your property. GSP Insurance Group is a for-profit independent agency that earns compensation when it places coverage on your behalf; the education here is general and not a substitute for a personalized policy review.

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The Six Parts of a Homeowners Policy — and Where Coverage B Fits

A standard home insurance policy is built from six distinct coverage parts:

• Coverage A — your dwelling (the main house itself)
• Coverage B — other structures (everything else on the property)
• Coverage C — personal property and contents
• Coverage D — loss of use / additional living expenses
• Coverage E — personal liability
• Coverage F — medical payments to others

Coverage B is the one most homeowners gloss over — until a storm takes out the detached garage or a fallen tree flattens the garden shed. Understanding it now, before you need it, is exactly the kind of preparation that makes a real difference.

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What Counts as an “Other Structure” on a Coastal SC Property?

This is where things get interesting for Lowcountry properties, which often include features you simply won’t find in a landlocked suburb.

Structures that typically fall under Coverage B on an HO-3 or HO-5 form include:

• Detached garages (the most common claim trigger)
• Storage sheds and outbuildings
• Fences, walls, and driveways
• Gazebos and pergolas
• Private docks and piers — a significant consideration in Beaufort County and around the Broad River, May River, and tidal creek communities of Bluffton
• Boathouses (though coverage scope varies by policy form)
• In-ground pools and pool enclosures

The key word is detached — structures that share a wall with the main house generally fall under Coverage A. If you’re unsure which bucket a structure falls into, a licensed GSP agent can review your insurance policy and clarify.

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A Lowcountry Scenario: The Bluffton Homeowner After a Named Storm

Picture a homeowner on a tidal creek off the May River in Bluffton. Their property includes a main house, a detached two-car garage, and a deep-water dock with a covered boathouse. A named tropical system moves through, delivering sustained winds and moderate storm surge.

Here’s what that homeowner might be dealing with under their home insurance:

The detached garage sustains wind damage — broken doors, roof shingles stripped, a rafter cracked. This is a Coverage B wind claim under the HO-3 form. But in coastal South Carolina, the wind/hail deductible is typically separate from the all-other-perils (AOP) deductible, and it is often expressed as a percentage of Coverage A rather than a flat amount. The South Carolina Department of Insurance regulates when and how these percentage-based deductibles can be applied in the state, and the deductible that applies to that garage repair may be substantially larger than the homeowner assumed.

The dock is a more complicated story — and this is a critical gap that every coastal homeowner in South Carolina needs to understand. Standard homeowners insurance policies generally cover docks under Coverage B for named perils like wind. But flood damage is entirely different. If storm surge lifted and destroyed the dock’s decking and pilings, that loss is almost certainly a flood claim, not a wind claim — and standard home insurance does not cover flood.

Flood coverage requires a separate policy, typically through the National Flood Insurance Program (NFIP) or a private flood insurer. But here’s an important wrinkle: the NFIP’s Standard Flood Insurance Policy (SFIP) generally excludes wharves, piers, and docks from coverage. That exclusion is codified in the SFIP policy form itself; you can review the NFIP’s official coverage documents and policy guidance at FEMA’s flood insurance resources. Even if you carry a flood policy, your dock may not be covered for flood damage under the NFIP program. A licensed GSP agent can confirm how the SFIP exclusions apply to your specific structure.

This distinction — wind damage versus flood damage — is one of the most consequential questions a Carolina homeowner faces after a storm, and it connects to a broader issue explained in the next section.

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Wind vs. Water: The Anti-Concurrent Causation Problem

When a tropical system causes both wind damage and storm surge simultaneously, something called the anti-concurrent causation (ACC) clause can complicate your claim significantly — and it appears in most standard HO-3 and HO-5 forms.

Here’s how it works: if a policy excludes flood and includes an ACC clause, the carrier may deny a loss that involved both wind and flooding at the same time, even if wind was the primary cause. The reasoning is that an excluded peril (flood) was contributing concurrently. In practice, this means a dock, boathouse, or even a detached garage that suffered both wind and water damage in the same storm could face a coverage dispute.

For the Bluffton homeowner on the May River, this isn’t a hypothetical. Surge and wind often arrive together during named storms that track up the South Carolina coast. The practical takeaways:

1. Document everything before a storm — photos, video, written inventory. Post-storm documentation is critical in any causation dispute.
2. Separate flood and wind policies work together, but are not seamless — they are administered independently, and you may need to work through both claims processes simultaneously.
3. A public adjuster or your insurance agent can help interpret the ACC clause as applied to your specific loss and policy form.

Understanding the ACC clause before you file a claim — not after — is one of the strongest reasons to have a real conversation with your agent about how your policies interact.

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The Coverage B Limit: Is It Enough for What You Have?

Coverage B is typically set somewhere in the range of ten to twenty percent of your Coverage A (dwelling) limit by default, depending on the carrier and policy form. South Carolina does not mandate a specific Coverage B percentage, so this varies — some carriers default to a lower end of that range, some offer higher options, and many allow the limit to be adjusted on request.

For many inland homes, a lower default is perfectly adequate. But consider a Hilton Head Island homeowner with a large detached garage, a private dock, a pool enclosure, and a storage outbuilding. Or a Myrtle Beach vacation property with a detached carport, a fenced yard, and a sizable shed. The combined replacement value of those structures could be substantial. If the Coverage B limit on your declarations page falls well short of what it would actually cost to rebuild everything, you’re carrying a gap in your coastal insurance protection.

The solution is straightforward: compare the Coverage B limit on your declarations page to your actual exposure. A GSP agent can help you think through the replacement costs of every structure on your property and recommend whether the limit should be adjusted.

Also worth considering: older structures may trigger ordinance or law requirements upon rebuilding — meaning you’d have to bring a dock, garage, or outbuilding up to current building codes at your own expense if the existing structure doesn’t comply. A licensed GSP agent can explain whether an ordinance or law endorsement makes sense for your property.

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Actual Cash Value vs. Replacement Cost — A Detail That Stings at Claim Time

Here’s another detail that surprises South Carolina homeowners at claim time: Coverage B may settle a loss on an actual cash value (ACV) basis rather than replacement cost value (RCV), especially for older structures. ACV means depreciation is applied — so a ten-year-old shed roof won’t be replaced at today’s material costs. You’d receive what that roof was worth after accounting for age and wear.

On an HO-5 form, broader replacement cost treatment is more common — but even then, structures like docks and older outbuildings may be subject to ACV settlement depending on how the policy is written. Confirm whether Coverage B on your insurance policy is written on an ACV or RCV basis before you need to file a claim.

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What Coverage B Does NOT Cover — Key Exclusions

Being clear about exclusions is part of being a good partner. Here’s what Coverage B in a standard HO-3 or HO-5 homeowners insurance policy typically will not cover:

• Flood damage — storm surge, tidal flooding, rising water. This requires a separate flood insurance policy, and as noted above, even NFIP flood policies generally exclude docks and piers per the SFIP form.
• Earthquake damage — requires a separate policy or endorsement.
• Gradual deterioration, rot, or wear — routine maintenance is the homeowner’s responsibility.
• Structures used for business purposes — if you operate a charter fishing business out of a detached waterfront workshop, or run any commercial activity from an outbuilding, a standard home insurance policy may not cover that structure for business-related losses. A separate commercial policy or endorsement may be needed.
• Structures rented to others — if you’re renting out a guest cottage or a boathouse slip, coverage becomes more complicated and may require a separate landlord or rental property policy.

If any of these scenarios apply to your property, a conversation with a GSP agent before you need to file a claim is time well spent.

The Insurance Information Institute’s overview of homeowners coverage is a helpful neutral reference for understanding what a standard policy includes and excludes across all coverage parts.

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Talk to a GSP Agent Before the Next Storm Season

If you own a home in coastal South Carolina — whether it’s a marsh-front property in Okatie, a canalside home on Hilton Head, or a neighborhood lot in Bluffton with a detached garage and backyard shed — Coverage B deserves the same attention you give your main dwelling.

The structures are real. The replacement costs are real. And the storms are real.

As an independent insurance agency serving the Lowcountry, GSP Insurance Group is compensated when we place coverage on your behalf — and we take that responsibility seriously. We take the time to walk through every part of your homeowners insurance with you, including Coverage B, so you understand what you have, what you might be missing, and what makes sense for your specific property. No pressure, no jargon, just a straightforward conversation.

Reach out to a GSP agent today and let’s make sure your whole property is protected, not just the main house.