An RV garage or boat storage building only does its job if it is sized to the vehicle you actually own, with every measurement pulled from a tape measure rather than a stock plan or a guess. That means a fully enclosed building, not an open-sided cover. If you want the building ready for winter storage, begin planning well before severe weather arrives, not after it forces the decision for you.
The most common mistake is measuring the vehicle and forgetting everything bolted to the top of it. Here is what to get right before you call an estimator.
Fully enclosed, not a carport
An open-sided cover keeps rain off the roof. Wind-driven rain and snow still reach the sides, and a cover does nothing for security. It does nothing for a boat's upholstery and electronics either. A steel RV garage or boat storage building has walls, a real door, and a roof engineered as one structure. That protects the whole vehicle, not just the top of it. Full enclosure blocks wind-driven rain and snow and improves security. Insulation, ventilation and moisture control are separate decisions to plan alongside it. Adding walls to a cover later almost never works as cleanly as building it enclosed the first time.
Measure the real rig, not the brochure number
A manufacturer's listed length and height rarely match what actually needs to fit through your door. Before you talk to an estimator, walk out to the RV or boat with a tape measure and get:
- Overall length, including the tongue and any rear ladder or bike rack
- Height to the top of the roof air conditioner, vents, or antenna, not just the roofline
- Width including mirrors extended
- Whether slide-outs need room to extend once the rig is parked inside
- Walking room you want on each side for hookups, storage, or a workbench
Write these down. Bring the real numbers to your estimator instead of rounding up in your head. Door height is hard to change once a building is engineered around a smaller opening. Measure the tallest thing you own, or plan to own, and add margin on top of that. Our guide to sizing a steel building covers the same logic beyond the door itself.
Door width, door height and eave height
The door is the real constraint on an RV garage, more than the floor plan. Height needs to clear the tallest point of your rig, with room to spare. Many RV garage doors run 12 to 14 feet tall and wide, and a tall Class A motorhome with roof-mounted air conditioning units often needs a clear height nearer 14 feet. Eave height follows the door, since a wall cannot be shorter than the door it holds. Width needs enough margin on both sides that pulling in does not feel like threading a needle. That margin matters even more if your approach to the door is not perfectly straight. Decide early whether you want a drive-through building, with a door on each end so you never back out, or a single door you back into. A drive-through layout requires a second opening. It also saves real frustration backing a trailer at night in the rain.
Boats bring their own numbers
A boat on a trailer has its own list. Trailer length with the tongue extended. Height with the outboard tilted up, or the outdrive down. The tallest point of a tower, hardtop, or bimini frame, whichever one you actually have. A wakeboard tower folds down on some boats and not others, so know which one you have before assuming a lower door will work. If you are storing more than one boat, size the door and eave to the tallest, not the average. A trailer with a tall tongue jack can also add a few inches you would not think to check standing next to the hull itself.
Power, ventilation and keeping things dry
An RV parked for winter usually needs a battery tender running. Plan an outlet near where the rig will actually sit, not just one by the door. A closed-up building with a fuel tank or an engine inside benefits from some ventilation, even simple passive vents, rather than sealing everything airtight. Boat owners in particular should ask their estimator about dehumidifying an enclosed building. Humidity trapped with no airflow is what causes mildew in cushions and corrosion on hardware. The building itself is rarely the problem; stagnant air inside it is.
Concrete apron and room to maneuver
The building is only half the plan. Leave a concrete apron in front of the door, wide enough to straighten out a trailer before you commit to backing in. Account for your tow vehicle's turning radius, not just the trailer's own length. A building that fits the rig perfectly but sits on a site with no room to maneuver outside the door creates a daily headache. That headache has nothing to do with the building itself, and everything to do with the site plan around it.
Leave room to grow
Most owners who store one RV or boat end up wanting a second bay within a few years. A second unit, a work vehicle, or a boat to go with the RV. If your site allows it, plan the building, or at least the pad, wide enough for a future bay. Boxing yourself in with a building sized exactly to what you own right now is a common regret. Northcraft's size guide is a reasonable starting point for comparing footprints before you settle on one.
Running a storage business instead of storing your own rig
Everything above is written for an owner storing a personal RV or boat. If you are planning a facility to rent units to other owners, the planning questions change. Unit mix and drive-aisle width for other people's trailers matter more than any single door height, and access for someone who has never backed a trailer before becomes its own design question. Northcraft's RV storage facility page is written for that buyer.
Frequently asked questions
How tall should an RV garage door be?
Many RV garage doors run 12 to 14 feet tall, with a tall Class A motorhome and its roof air conditioner often needing the full 14 feet. Measure your own unit, including roof air conditioners, vents and antennas, rather than relying on the vehicle's advertised height, then tell your estimator the exact figure so the wall and door are engineered to match.
How wide does an RV garage need to be?
Wide enough that pulling in does not feel like threading a needle, with extra margin if your approach to the door is not straight. If you are storing more than one unit side by side, add walking room between them, not just door-to-wall clearance.
Do I need to heat an RV storage building?
Not necessarily. Plenty of owners store successfully in a building that is fully enclosed and insulated but unheated. Heat matters more if you plan to winterize inside the building yourself, or if you want to use the space as a workshop through the cold months.
Can I store a boat and an RV in the same building?
Yes, as long as the door and eave height are sized to the taller of the two, and you plan floor space for both from the start. Tell your estimator every measurement for both units so neither one becomes an afterthought.
Does an RV garage need a concrete floor?
Most owners pour concrete for a clean, dry floor and an apron to stage the vehicle before pulling in. See our guide to concrete slabs for a steel building for what goes into that decision.
Start with real measurements instead of a guess, and give your estimator every number, including the ones that feel close enough. Tell us the size of what you are storing and where it is going, and an estimator will run the numbers for your site.