A 4 season camper out of the box: double-hull fiberglass, enclosed holding tanks, dual-pane windows and a ducted propane furnace standard. Built for cold-weather camping and summer heat across all 50 states and Canada.
How well a cold weather camper holds heat depends on its walls. Every Oliver is two fiberglass hulls bonded together with a double-sided radiant barrier and an air gap between them, so the insulation is built into the structure.
Oliver’s double-hull fiberglass shell and radiant-barrier insulation hold interior temperatures stable from sub-zero nights to triple-digit summer days, while cutting the energy load on the furnace and AC. Every insulated 4 season camper Oliver builds comes with that cold-weather capability standard, so there is no package to add.
See How The 4 Season Build WorksInsulated Wall Cross-Section
Outer fiberglass hull
Dead air space
Radiant barrier
Inner fiberglass hull
Hand-laid gelcoat fiberglass, molded as an upper and a lower shell.
Dead air between the hulls slows heat moving in either direction.
Double-sided, so it reflects heat back out in summer and back in during winter.
Bonded to the outer shell, so the two move as a single structure.
Heat travels by conduction, convection and radiation, and this wall interrupts all three in both directions.
Plenty of trailers advertise cold-weather capability. What separates them is whether the trailer was engineered as a 4 season camper or built as a three-season trailer and fitted with parts to compensate. Here is what to check before you buy, on any brand.
| What to check | Oliver double hull | Typical framed trailer with a winter package |
|---|---|---|
| Insulation and wall construction | Two hand-laid fiberglass hulls bonded into one shell | Aluminum or wood frame with panels laminated to it |
| Heat transfer addressed | Conductive, convective, and radiant, in the same wall | Usually conductive only, through added foam or batting |
| Structure | ✓Fiberglass shell on an aircraft-grade aluminum frame | ×Wood framing in floors, walls, and roof decking |
| Plumbing and holding tanks | Enclosed inside the shell, standard | Often exposed underneath, heat pads sold as an option |
| Cold weather camping capability | ✓Built in, no package to select | ×An upgrade added to a three-season trailer |
| Heating and airflow | Ducted propane furnace, dual 20-lb tanks with auto switch-over, MaxxAir Fan Deluxe | Varies by trim; single tank and basic vent are common |
| Summer performance | Same shell works in reverse; a roof-mounted Houghton A/C is standard, 120V on the Legacy Elite II and 48V on the Apex X23. | Winter packages rarely improve hot-weather performance |
| Where it is built | Hohenwald, Tennessee, and you can come for a factory tour. | Factory access is uncommon |
The right-hand column describes construction methods that are standard across much of the towable RV industry. Specifications vary by manufacturer and model year, so confirm details on any trailer you are considering.
Both 4 season campers carry the same double-hull shell and the same standard climate equipment. The difference is size, power, and how far off-grid you plan to get. Every Oliver is built to order in Hohenwald, Tennessee and sold factory outlet direct.
Most Popular
Twin Axle · Sleeps 3
Off-Grid Build
Quad Double-Hull · Sleeps 3
Looking for one ready now? Build slots and finished units change week to week, and a few are usually available without the full build wait.
See 4 Season Campers Available NowThe Shell
Oliver’s wall system addresses all three ways heat moves: the fiberglass shells slow conduction, the air gap between them slows convection, and a double-sided radiant barrier reflects radiant heat.
Winter and Summer
Oliver’s enclosed plumbing, ducted propane furnace and A/C all come standard, so every Ollie leaves the factory ready for sub-zero winters and hot summers without an add-on package.
Standard Equipment
Every Oliver ships with dual 20-lb propane tanks with auto switch-over, a ducted propane furnace, a roof-mounted Houghton A/C and a MaxxAir Fan Deluxe.
Owners
Ask Oliver owners why they chose their trailer and two answers keep coming up: four-season freedom and a bug-free interior. The double-hull fiberglass construction keeps you camping comfortably whether it’s July in the desert or January in the Rockies.
A full walkthrough of the Legacy Elite II, how the climate control holds up in real heat, and an owner on why he chose a 4 season camper instead of a winter package.
Full Walkthrough
Summer Heat
Owner Testimonial
Most travel trailers are built behind closed doors, but Oliver invites you in. Walk the floor where two fiberglass hulls are laid up by hand and bonded into one shell, see the plumbing get enclosed before the second hull goes on, and meet the people doing it.
A 4-season travel trailer is built to stay comfortable and usable whether you are camping through a January blizzard or a triple-digit August afternoon. The difference from a standard RV is thermal performance: more insulation, protected plumbing, and climate systems sized for temperature extremes. Most 4-season trailers also use dual pane windows and ducted heating.
The outer shell matters most. Oliver uses a double-hull fiberglass design: two hand-laid layers bonded into one shell with insulation and an air gap between them, which works the way a double-pane window does and slows heat transfer in both directions. Add dual pane windows, enclosed plumbing and holding tanks, and a ducted propane furnace, and the trailer holds interior temperature with less work from the heating and cooling systems.
The shell is two hand-laid fiberglass hulls bonded into one piece, with insulation and an air gap between them, sitting on an aircraft-grade aluminum frame with a galvanized steel sub-assembly. The holding tanks, plumbing and drain lines are enclosed inside the shell instead of hanging underneath it. Dual pane windows, a ducted propane furnace and roof air conditioning are standard on every 2027 build, so the four-season equipment comes with the trailer.
Owners post trip reports from Alaska, the upper Midwest and the desert Southwest in the Oliver owner forums, covering sub-zero nights and summer heat. Those reports are public, and they are the most direct account available of how the trailers behave in the field. The four-season equipment described above is standard on every build, so it is the same equipment in every trailer those owners are towing.
Cold-weather capability is often sold as an optional package: heated tank pads, added insulation, aftermarket weatherproofing. Oliver builds the protection into the structure. The insulation sits between the two bonded fiberglass hulls, and the holding tanks, plumbing and drain lines are enclosed inside the shell instead of hanging underneath and depending on a heating element to stay above freezing.
It depends on whether you are camping or storing. While you are camping in freezing weather there is nothing extra to buy: the holding tanks, plumbing and drain lines sit enclosed inside the shell rather than hanging underneath, so running the furnace keeps them inside the heated envelope. People get this wrong on every brand, Oliver included: the heat has to be running, and a trailer left cold for a few days in a hard freeze will freeze its enclosed plumbing like any other. For storing it unheated through winter, yes, winterize it, the same as any RV with water in its lines. Oliver publishes a step-by-step winterization guide for exactly that.
The right answer depends on what winter camping means for you. For sustained below-zero temperatures, remote sites, or shoulder-season camping without hookups, you want enclosed plumbing, a ducted propane furnace, and a shell that holds heat. In the 2027 Oliver lineup, the Legacy Elite II and the Apex X23 carry that equipment as standard on every build. The Legacy Elite is fully booked for 2026 production.
A few things make a difference on long cold-weather stays. Every Legacy Elite II and Apex X23 comes with lithium batteries, which handle low temperatures better than AGM, and solar is standard on the Apex X23 and on the Legacy Elite II from the Premium trim up. Run the propane furnace at a lower, steady setting instead of cycling it on and off, which wastes fuel. If you skirt the trailer in sustained freezing temperatures, keep the furnace intake and exhaust vents clear and check them again after any snowfall: a blocked vent risks carbon monoxide entering the trailer. Watch your propane level closely, because consumption climbs sharply in the cold and running out overnight in sub-zero conditions is dangerous.
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