The first thing to know about any rooftop tent annex is that it is model-locked. An annex clips or zips into a specific channel or rail on one specific tent, and it will not cross over to a rival brand no matter how similar the two tents look from the road. That single fact decides which of the best annex rooms for rooftop tents you can actually buy, so every entry below names the exact tent it fits before it names anything else.
What is a rooftop tent annex? A rooftop tent annex is a fabric room that attaches to the underside of your rooftop tent, usually into a rainfly channel or base rail, enclosing the ground-level space beneath the ladder. It adds three things to a camp: a weatherproof changing room, a dry place for muddy gear, and floor space for an extra sleeper.
Changing room: get dressed and dressed down out of the weather, which matters most in the first ten minutes of rain at 6am.
Gear storage: boots, a recovery board, a duffel and a dog all stay off the tent floor and out of the downpour.
Overflow sleeping: with a floor in place, a family of three or four can sleep under the tent instead of beside the vehicle.
We spent weeks reading spec sheets, owner reviews and forum threads across r/rooftoptents, r/overlanding, the Bronco 6G forum, ih8mud and expeditionportal, and we compared every unit below against the one thing buyers most often get wrong: fit. This roundup is written for people who already own a tent and want to add a room underneath it, and it is updated for 2026. We do not publish prices in this guide because they move with every sale in this category; the buttons below carry the current figure for each item.
If you are still choosing the tent itself rather than the annex, start with our guides to the best rooftop tents for overlanding and the best rooftop tents for trucks, then come back here once you know the model on your rack.
Table of Contents
- Top 3 Picks for Best Annex Rooms for Rooftop Tents (October 2026)
- All 10 Best Annex Rooms for Rooftop Tents in 2026
- Annex vs Awning vs Standalone Tent
- Why Wedge and Hardshell Owners Have So Few Options
- 1. ARB 804100 Simpson III Annex for Brown Roof Top Tent
- 2. Smittybilt Gen2 Overlander Annex SB2588
- 3. Overland Vehicle Systems TMBK Annex Room
- 4. Overland Vehicle Systems HD Bushveld 2 Annex Room
- 5. Naturnest Sirius 1 Plus Annex Room
- 6. Tuff Stuff Roof Top Tent Annex Room for Delta Overland and Trailhead
- 7. Overland Vehicle Systems XD Sherpa S4S Annex Room with Floor
- 8. Ironman 4×4 Cross 1200 Annex Room
- 9. Body Armor 4×4 Sky Ridge Pike 3 Annex Room
- 10. Thule Approach Annex for Hardshell Rooftop Tents
- How to Choose a Rooftop Tent Annex
- Frequently Asked Questions
- Final Verdict
Top 3 Picks for Best Annex Rooms for Rooftop Tents (October 2026)
The ARB 804100 Simpson III annex takes the top slot because it is the only unit in this roundup with both a meaningful owner review history and a two-year warranty behind it. The Smittybilt Gen2 annex is the one to buy if you want a removable floor and full waterproof rating in a package that sets up fast. The Overland Vehicle Systems TMBK annex earns its spot with the heaviest fabric spec in the group and a four-year warranty.
Smittybilt Gen2 Overlander Annex
- 2000mm fabric
- Removable zippered floor
- Fits part 2583 only
All 10 Best Annex Rooms for Rooftop Tents in 2026
Every row below is a room that fits one named tent. There is no universal-fit option in this category, and the fits column is the reason to read the table before the specs. We have listed the fabric rating and floor detail first because those two specs decide whether the room is a dry changing space or a leaky one.
| Product | Specifications | Action |
|---|---|---|
 ARB 804100 Simpson III Annex |
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Check Latest Price |
| Smittybilt Gen2 Overlander Annex |
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Check Latest Price |
 OVS TMBK Annex Room |
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Check Latest Price |
 OVS HD Bushveld 2 Annex Room |
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Check Latest Price |
 Naturnest Sirius 1 Plus Annex |
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Check Latest Price |
 Tuff Stuff Delta and Trailhead Annex |
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Check Latest Price |
 OVS XD Sherpa S4S Annex Room |
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Check Latest Price |
 Ironman 4×4 Cross 1200 Annex |
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Check Latest Price |
 Body Armor 4×4 Sky Ridge Pike 3 Annex |
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Check Latest Price |
 Thule Approach Annex |
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Check Latest Price |
Annex vs Awning vs Standalone Tent
The most common confusion we see in forums is people describing a walled side awning as an annex. In the r/overlanding thread on sleeping four, a camper explains using an ARB awning with four walls and a floor as ground-level living space under the tent. That is a legitimate setup, but it is a different product from everything on this list.
An annex is zipped or clipped to the underside of the tent itself, which means it moves with the tent, takes the same footprint as the tent above it, and disappears entirely when you fold the tent away. An awning bolts or clamps to the rack or the tent base and stands on its own legs, so you can position it away from the vehicle and leave it pitched while the tent is closed. A standalone tent sits on the ground beside the vehicle with no attachment at all, which makes it the cheapest option per night of use and the least integrated.
The practical differences come down to four things:
Footprint: an annex uses the space under the tent, an awning needs clear ground beside the vehicle, a standalone tent needs the most room of all.
Pack-down: an annex folds with the tent, an awning collapses to a bag you still have to stow, a standalone tent is a separate load.
Flexibility: only an awning can be moved to shade a different part of the camp, or left standing in wind while the tent is packed.
Best use: annex for a dry changing room attached to your bed, awning for cooking and shade, standalone tent for a second sleeping area away from the vehicle.
Owners of softshell setups have been moving away from annex rooms toward wedge tents with awnings, and one camper in a desert overlanding group described the switch as trading a room for a lighter, more modular setup. Both answers are valid; they just solve different problems.
Why Wedge and Hardshell Owners Have So Few Options
The top-ranking result for this query is a Reddit thread on r/rooftoptents asking why nobody makes annexes for wedge tents, and the honest answer is that the shape works against it. A wedge shell tapers to a narrow base and has no flat rail or channel running along the underside, which is exactly the feature an annex needs to hang from. Softshell Overlander-style tents have a rectangular base with a fabric perimeter, so the attachment problem solves itself.
Yakima’s SkyPeak HD annex is the option most wedge and hardshell owners are pointed toward, and for many of them it is the only one. Hardshell models from Thule, iKamper’s BDV and Roofnest fall into the same trap, with a small or inconsistent accessory catalogue. If you own a hardshell and nothing below matches your tent, the realistic options are to run a side awning as a walled room, commission a custom fabric job, or accept a standalone tent beside the vehicle.
Fitment is also where premium builds disappoint. A Bronco 6G forum owner of the iKamper BDV annex reported that the directions were poor and that it only mounted to one side of the tent, which is the kind of defect worth checking for before you rely on it in weather. Ask the seller for a photo of the annex zipped to your exact model before you commit.
1. ARB 804100 Simpson III Annex for Brown Roof Top Tent
ARB 804100 Simpson III Brown Rooftop Tent Annex/Changing Room
Fits ARB Simpson III
1200mm polyester
Two rooms for 4 people
13 lb packed
51 inch peak height
Pros
- Build quality owners report lasting for years
- Heavy-duty zippers stay smooth
- Weathered storms with no rain penetration
- Two-room layout for 4 people
Cons
- Vague instructions and two people needed to lift it
- Supplied pegs spin in the ground and let walls flap
- No floor included
This is the annex with the deepest owner history in the category, and that is why it leads the list. Owners on the ARB Simpson III talk about zippers still running smoothly after seasons of use and about the room holding its shape through wind-driven rain. At 13 pounds packed it is also one of the lighter rooms here, which matters when you are already carrying a tent, a ladder and a mattress.
What you get is a two-room, four-person build in polyester rated to 1200mm of water resistance, with aluminium poles and a 51 inch peak. The two-room split is genuinely useful: one half is a changing and gear space, the other can hold boots and a camp kitchen without the smell migrating into your sleeping bag. The overall 3.6-star average is honest and worth reading as a mixed report rather than a failure.
The recurring criticisms are all fixable. Instructions are vague enough that owners recommend having the manual open on a phone while a second person holds the other side, and the included pegs have a round cross-section that spins in soil and lets the walls flap. A pack of proper forked or Y-section stakes makes a measurable difference on a windy night.
The one spec that would change our recommendation is the missing floor. This room ships without one, so a separate groundsheet is needed before anyone sleeps in it or stores gear on the ground. The good news is that a floor is cheap and easy to add.
Will the 804100 fit your Simpson III, and does it need a floor?
This is the pick for ARB Simpson III owners who camp more than a couple of nights and change in the rain. Owners on the ih8mud forum pair the Simpson III with the FrontRunner annex for the same function at a lower outlay, describing it as light duty next to an Eezi-Awn, so the FrontRunner is the budget route and this is the warranty-backed one.
When the missing floor and vague instructions should stop you
Skip it if you plan to sleep two people inside. There is no floor in the box, and adding one is an extra step most people skip. Anyone wanting a guaranteed dry floor or a lightweight pack will find the Smittybilt and Tuff Stuff options in this list better aligned.
2. Smittybilt Gen2 Overlander Annex SB2588
SmittyBilt OVRLND GEN2 TENT ANNEX – SB2588
Fits GEN2 Overlander 2583 only
2000mm waterproof
Removable zippered floor
12 lb packed
Pros
- Precise fit on the matching Gen2 tent
- Quick setup and pack-down
- Removable floor keeps out mud and insects
- Four pockets and four guylines included
Cons
- Fits only part number 2583 and not the XL
- Listing video misleads buyers about XL fit
- 3.5 stars with a share of 1-star ratings
This is the annex most owners of the second-generation Overlander will find in their search, and for them it does one thing well: it adds a private room under the ladder that zips on and comes off quickly. Owners report a precise fit, smooth heavy-duty zippers and a setup that is noticeably faster than pitching a ground tent of the same size.
The spec sheet is the strongest in the value tier. The fabric is polyurethane-impregnated polyester rated to 2000mm, which is well above what most of this list claims, and the heavy-duty removable floor is zipped in rather than laid loose. That floor is the detail that turns this from a privacy screen into usable sleeping space for a third person.
The catch is stated plainly on the product itself: it only works with the GEN2 Overlander, part number 2583. It does not fit the XL, and the listing video has caused real confusion on that point, which is where a share of the 1-star ratings comes from. Check your part number before anything else.
Does the SB2588 fit your Overlander, and is part 2583 yours?
Overlander Gen2 owners who want a floor, a weatherproof rating and a fast pitch. The inner door flap gives direct access to the vehicle, which makes it work as a wet-weather gear room as much as a bedroom.
What the 2000mm rating and removable floor actually change
Anyone with the XL model, or anyone hoping for a room that fits more than one tent. The four-person rating is a floor-area rating rather than four comfortable sleepers, and the 3.5-star average tells you some buyers were disappointed on fitment rather than build.
3. Overland Vehicle Systems TMBK Annex Room
Overland Vehicle Systems LD TMBK Roof Top Tent Annex Green Base with Black Floor & Travel Cover – 420D Polyester Oxford Waterproof Material -1000g PVC Based Floor
Fits OVS TMBK
420D Oxford body
1000g PVC removable floor
4-season
4-year warranty
Pros
- Heaviest fabric spec in the group
- Removable PVC floor wipes clean easily
- Roll-up windows and doors for airflow
- Four-year warranty from the manufacturer
Cons
- Made only for the TMBK tent
- Just one rating on record so far
The TMBK annex is the most thoroughly specified room in this roundup, and the build reads like a two-year-old rather than a weekend project. The body is 420D polyester Oxford waterproof material, the windows and doors are 120g fadeless breathable mesh, and the floor is a 1000g PVC-based panel that zips in and lifts out for cleaning.
Those roll-up windows and doors are the part we would highlight. They let you strip the room back to airflow in summer without unhooking anything, and the hook-and-lock roll covers keep the mesh shut when you want privacy or blackout. Storage bag and travel cover are included, so the whole thing collapses into the same bag as the tent.
We are rating this on a very thin evidence base. It carries a single owner rating of five stars, and while that owner liked the fabric and the removable floor, one review tells you almost nothing about how the seams and zippers hold up after a season of wind. The four-year warranty is the strongest safety net any annex in this list carries.
What the removable PVC floor and mesh panels give you
TMBK owners who camp hard and want a wipe-clean floor and a long warranty. The four-season rating and mesh ventilation make it the most balanced room for mixed summer and shoulder-season trips.
What one five-star review cannot tell you
Skip it if you want verified long-term feedback, because there is almost none on record. It also has no value outside the TMBK, so confirm the model on your rack before you fall for the spec sheet.
4. Overland Vehicle Systems HD Bushveld 2 Annex Room
Overland Vehicle Systems 18189902: Hd Bushveld 2 – Annex Room, Window & Doors, Green Body & Grey Trim
Fits Bushveld II
No drilling or modification
420D Oxford
120g mesh window
17 lb packed
Pros
- Installs without drilling or modifying the tent
- 420D Oxford waterproof body
- Breathable mesh window for ventilation
- Green body with grey trim to match the tent
Cons
- No owner ratings on record
- Only fits the Bushveld II and nothing else
If you own a Bushveld II and you are worried about drilling holes in an expensive tent, this is the annex built for that exact concern. The manufacturer states no drilling or modification is required, and the room attaches with heavy-duty grommets and quick-release zips rather than fixed hardware.
The fabric matches the rest of the Overland Vehicle Systems range, which is worth something. A 420D polyester Oxford body and a 120g environmental fadeless mesh window mean the material should age at the same rate as the tent above it, and the green body with grey trim lines up visually rather than looking like an add-on.
At 17 pounds packed this is one of the heavier rooms here, and the listing is classified as an awning rather than a tent, which is a clue about how it is shaped. There is no owner rating at all, so every claim above comes from the manufacturer’s specification sheet rather than from people who have used it.
Will this annex mount without drilling your Bushveld II?
Bushveld II owners who refuse to drill their tent and want matching fabric and colour. It is a clean, low-risk install compared with hardware-mounted alternatives.
What 17 pounds and zero owner reviews mean for your decision
Anyone who wants to see how it performs after a year of use, and anyone without a Bushveld II. With no ratings and no floor specification, you are buying on the strength of the material spec alone.
5. Naturnest Sirius 1 Plus Annex Room
Naturnest Sirius 1 Plus Annex Room for Naturnest Sirius 1 Plus Rooftop Tent Only, Not Include Rooftop Tent
Fits Sirius 1 Plus only
420D blackout
143.7 x 83.5 x 71 inch
10-minute setup
35 lb
Pros
- Kept one owner warm and dry through a rainstorm
- Very fast setup and breakdown
- Blackout fabric with a switchable mesh window
- Large footprint for a ground-level room
Cons
- 35 lb is the heaviest pack in this roundup
- Condensation is inevitable in wet weather
- Only pairs with the Sirius 1 Plus and the tent is not included
At 143.7 by 83.5 by 71 inches this is the largest ground-level footprint in the roundup, and it is the one to look at if you want to actually sleep two people underneath the tent rather than sit in a small changing room. The fabric is 420D tear-resistant material in a blackout build with a breathable mesh window for when you want light and air.
Setup is the standout. The room connects to the rail under the tent with hook-and-loop, then a support pole, wind ropes and ground nails finish it. The manufacturer quotes roughly ten minutes, and the one detailed owner review backs that up, describing a week-long road trip where the annex was used as a home and pitched and packed faster than any ground tent the owner had used.
Two cautions. The 35-pound pack weight is the heaviest in this list by a wide margin, and that bulk has to live somewhere in your vehicle. The owner also reports that condensation is inevitable and that every zipper must be closed in wet weather, which is true of any enclosed fabric room.
Can two people actually sleep inside this annex?
Sirius 1 Plus owners who want a real second room for two sleepers and value a blackout build. The mesh window gives you privacy or ventilation without taking the whole wall down.
Where the 35-pound pack weight becomes a problem
Skip it for short trips or if packed bulk matters, and skip it if you want the tent bundled with the room. The tent is sold separately, and the room is strictly for the Sirius 1 Plus.
6. Tuff Stuff Roof Top Tent Annex Room for Delta Overland and Trailhead
Tuff Stuff Roof Top Tent Annex Room, W/Floor, Delta Overland & Trailhead TS-ANX-DLT-TH
Fits Delta Overland and Trailhead
Floor included
Tan colourway
1-year warranty
Pros
- Covers two rooftop tent models with one room
- Floor is supplied in the box
- Tan colourway that suits most vehicle setups
- Backed by a 1-year manufacturer warranty
Cons
- No owner ratings or measurements published
- Limited specification detail in the listing
This is the rare annex that covers two tents in the same brand, the Tuff Stuff Delta Overland and the Trailhead, which means one purchase can follow you across a rig change. It is a straightforward tan room that ships with a floor already included, which removes the most common upgrade step.
Including the floor is what puts it ahead of the ARB in this roundup for anyone whose priority is sleeping rather than standing. You can pitch it, put a sleeping mat in and use it the same night, and you do not have to work out how a separate groundsheet fits the footprint.
What we cannot tell you is anything about weight, dimensions or fabric, because the listing publishes none of it. There are no owner ratings either. The 1-year manufacturer warranty is the shortest in this roundup, so treat it as a straightforward accessory rather than a long-term build.
Does one room really cover both the Delta Overland and Trailhead?
Owners of either the Delta Overland or the Trailhead who want a room with the floor already solved. It is the simplest path from bare tent to usable extra space.
What to confirm yourself before ordering with no specs published
Buyers who need published specifications or verified owner feedback before committing. If you care about waterproof rating, packed weight or ventilation, this listing will not give you those answers.
7. Overland Vehicle Systems XD Sherpa S4S Annex Room with Floor
Overland Vehicle Systems 18009811: Xd Sherpa S4S – Annex Room with Floor, Black Body & Grey Trim
Fits XD Sherpa S4S
Floor included
Easy-setup attachment
4-season
Black with grey trim
Pros
- Floor is part of the room rather than an add-on
- Marketed as an easy-setup fit for the S4S
- 4-season rated
- Black body with grey trim
Cons
- The only recorded review is 1 star
- Very little review history to judge from
The Sherpa S4S annex comes with a floor in the box and is described as an easy setup, which is a simple combination for a first-time annex owner. It is a rectangular room rated for four-season use in a black and grey colourway that sits quietly against most racks.
We are including it because a floor-inclusive, easy-setup option for a specific tent is a real gap in this list, and because we would rather show you the weak evidence than hide it. The single recorded customer review is one star, with no written detail explaining what went wrong. That is not enough to conclude the product is faulty.
It is enough to say that you would be buying this one on the manufacturer’s description rather than on owner experience. Check the fitment for the S4S against your tent before ordering, and keep your own groundsheet in mind in case the supplied floor is not the coverage you want.
Is a floor included, and how long does setup take?
XD Sherpa S4S owners who want the floor included and the shortest possible setup. The 4-season rating suits anyone running trips that span more than summer.
What a single 1-star review should and should not tell you
Anyone who wants proven owner feedback. With one 1-star rating and no review text, there is no evidence here about how the zips or seams wear in, and that is the part that decides whether a room stays dry.
8. Ironman 4×4 Cross 1200 Annex Room
Cross Roof Top Annex Room Tent 1200 by Ironman 4×4 AUS
120 x 80 x 120 inch
4-person capacity
Weather-resistant fabric
20 lb packed
Spring to fall
Pros
- Large enclosed space for four people
- Zippered access panels for weather cover
- Attaches to the rooftop tent without a separate frame
- Wipe-clean care and compact storage
Cons
- Listed as water resistant rather than fully waterproof
- No owner ratings on record
- Rated for spring summer and fall only
The Cross 1200 is the biggest room by published dimension in this roundup at 120 by 80 by 120 inches, and it is rated for four people. That size makes it a dining and living room rather than a changing cubby, which is a different use case from most of the other rooms here.
Construction is described as weather-resistant fabric with zippered access panels, and the manufacturer suggests it for dining, changing, additional sleeping or a private lounge. Care is straightforward: wipe with a damp cloth and store it dry, which is one of the easier maintenance routines in this list.
Two honest limits. The listing states water resistant rather than fully waterproof, so in sustained rain you would be relying on the host tent above as the primary weather barrier. It is also rated for spring, summer and fall, which rules it out of winter basecamps. At 20 pounds packed it is the second-heaviest room here.
Is the Cross 1200 big enough to use as a living room?
Families or groups who want one ground-level room for eating, drying gear and sitting, rather than a small changing room. The dimensions and 4-person rating suit that use.
Where water resistance and the three-season rating fall short
Cold-weather campers and anyone who needs a guaranteed waterproof floor. The three-season rating and water-resistant construction are the wrong tools for winter or exposed-season travel.
9. Body Armor 4×4 Sky Ridge Pike 3 Annex Room
Body Armor 4×4 Sky Ridge Pike 3 Annex Room 20016
Adds 52 sq ft
420D ripstop Oxford
550GSM PVC floor
Door plus two windows
Pros
- Adds a large 52 sq ft of downstairs space
- 420D ripstop polyester Oxford body
- 550GSM PVC coated waterproof floor
- Entry door plus two large windows
- 2-year finish with limited lifetime warranty
Cons
- No owner ratings on record
- No UV protection in prolonged sun
- Tent and rack sold separately
This room adds 52 square feet of downstairs living space, which is one of the larger footprints in the roundup, and it arrives with a floor that is heavier than most. The body is 420D ripstop polyester Oxford and the floor is 550GSM PVC-coated waterproof fabric, so both surfaces are specified well above entry-level kit.
An entry door and two large windows give light and airflow, which is what stops a room this size from becoming a dark box in summer. The warranty is a 2-year finish with a limited lifetime manufacturer warranty, and that lifetime element is rare in this category.
It is fitted to the Sky Ridge Pike 3 rooftop tent, and the tent and rack are separate purchases. There are no owner ratings yet and no UV protection in the fabric, which matters if you park in open sun for days at a time. We would add a sun cover on the roof panel for long, exposed stays.
How much usable space does the 52 sq ft actually add?
Sky Ridge Pike 3 owners who want maximum downstairs area with a serious floor. The door-and-two-window layout works well for a gear room the whole family uses.
What to watch without UV protection or owner history
Buyers who want verified owner reports, and anyone who leaves gear in direct sun for long periods. Check your tent model first, since this room is built for one rooftop tent only.
10. Thule Approach Annex for Hardshell Rooftop Tents
Thule Approach Annex for Small Approach Rooftop Tent New, Adjustable Height
Doubles Approach living space
Roll-up doors
215 cm max height
Removable tarpaulin floor
Pros
- Roll-up doors convert the annex into an open awning
- Adjustable height for 63 to 85 inch clearance
- Mesh windows for ventilation
- Removable tarpaulin floor
- Limited lifetime warranty
Cons
- Listed as water resistant rather than waterproof
- 3.2 stars with a large share of 1-star ratings
- Needs a compatible Approach tent and the right vehicle height
The Thule Approach annex is the hardest-shell option in this roundup, and it is the one to look at if you have an Approach tent. The front and side doors roll up, which turns the enclosed room into an open awning on the same frame, so you get two configurations from one piece.
Height is adjustable, and the manufacturer recommends vehicles with a ground-to-tent-base distance between 63 and 85 inches. That measurement matters more than anything else on this list, because if your rack height falls outside the range the room simply will not stand correctly. Maximum interior height is 215 centimeters and it is rated for two people.
Construction is 100% recycled polyester with a removable tarpaulin floor, mesh windows and a limited lifetime warranty, which is the longest warranty in the roundup. The catch is honest: it is listed as water resistant rather than fully waterproof, and the 3.2-star average from two ratings is split roughly evenly between delighted and disappointed owners.
Will your rack height fall inside the 63 to 85 inch range?
Approach tent owners with a compatible rack height who want one product to work as a closed room and an open awning. The recycled polyester and lifetime warranty suit owners planning to keep the tent for years.
What a 3.2-star average across two ratings signals
Anyone outside the 63 to 85 inch clearance window, and anyone who needs a guaranteed waterproof room. The 2-person rating and small vestibule area make it a compact room, not extra sleeping capacity for a family.
How to Choose a Rooftop Tent Annex
Start with fit, every time
Do not read a single feature until you have confirmed the annex is made for your exact tent model. The attachment is a channel or rail on the tent, and each manufacturer uses its own, so fitment is not a matter of size. Check the part number, not just the brand, because several of the rooms above cover one model and explicitly exclude the XL or 2X version of the same tent.
Decide between a changing room and a sleeping room
A removable floor is the single spec that decides this. Without a floor, the room is a vestibule for standing up, storing boots and keeping rain off your kit. With a zipped or removable floor, it becomes floor space for a third person or a child. Rooms that ship without one, like the ARB, need a separate groundsheet before anyone sleeps in them, and a few owners use the annex as a home for a week at a time.
Check headroom and airflow
Peak height ranges widely in this category, from the ARB at 51 inches to rooms published at 71 inches and beyond. If you plan to stand and dress, treat anything under about 50 inches as a crouch. For summer heat, look for roll-up panels or mesh doors that open without unhooking the room, because a sealed fabric box in July is a sauna.
Weigh fabric and waterproofing against your seasons
Fabric ratings in this category run from 1200mm on the ARB to 2000mm on the Smittybilt, with several rooms described only as water resistant. For shoulder-season and wet-climate trips, pick the highest rating you can get. For genuine cold-weather use, remember that an annex inherits the thermal limits of the tent above it; campers on expeditionportal credit an insulated roof and double canvas walls for heat retention, and ducted heaters get used inside enclosed rooms when the host tent is not enough.
Understand weight and packed bulk
Because the annex sits on the ground, its weight adds nothing to your rack’s dynamic load. The 20 pounds of the Ironman room and the 35 pounds of the Sirius 1 Plus annex are carried in the vehicle, not on the bars, though both add real bulk to a packed kit. Layout of your rack and crossbar spacing still matters for the tent itself, and you should confirm your bar spacing supports the ladder angle and load for the tent you own.
Anchor it properly in wind
The anchor points are what owners consistently warn newcomers about. Replace round-cross-section pegs with forked or Y-section stakes, use every guyline and stake supplied, and expect aluminium poles to flex in a gust rather than treat it as a failure. On rocky ground, look for extra guy-out points before you pitch, not after the first strong night.
Dry it before you store it
An enclosed room that is packed damp will grow mildew in the fabric and the floor, and mildew in a sealed bag is permanent. Wipe the floor down, air the room for a day in the shade, and only then stuff it into its bag. The Ironman and Body Armor floors are both easy to wipe clean, which makes that habit quicker on those two.
Still working out what the rest of your setup needs? Our picks for the best rooftop cargo bags cover the other half of the problem, and our best rooftop tents for SUVs guide covers the platforms most annex buyers are fitting out.
Frequently Asked Questions
What is an annex for a roof top tent?
A rooftop tent annex is a fabric room that clips or zips to the underside of your rooftop tent, usually into a rainfly channel or base rail, enclosing the ground-level space beneath the ladder. It adds a weatherproof changing room, dry gear storage, and floor space for an extra sleeper without putting any weight on your roof rack.
Do rooftop tent annexes fit any tent?
No. An annex is model-specific and does not fit across brands, because it attaches to a channel or rail unique to one tent design. Check the exact model and part number before buying, and note that several annexes exclude the XL or 2X version of the same tent.
Can you sleep in a rooftop tent annex?
Yes, if it has a floor. A removable or zipped floor is the spec that turns a changing room into usable sleeping space for a third person or a child. Rooms shipped without a floor, such as the ARB 804100, need a separate groundsheet, and most owners treat sleeping inside as fair-weather use only.
How much weight does a rooftop tent annex add to my setup?
Nothing to your roof rack. The annex stands on the ground, so its packed weight, which ranges from about 12 pounds on the Smittybilt Gen2 to 35 pounds on the Naturnest Sirius 1 Plus, is carried in the vehicle rather than on the crossbars. It does add bulk to a packed kit.
Why are there so few annexes for wedge tents?
Wedge shells taper to a narrow base with no flat rail or channel underneath, which is exactly what an annex needs to attach to. The Yakima SkyPeak HD annex is the most commonly cited option, and hardshell models have a smaller accessory catalogue still. If nothing matches, a walled side awning or a standalone tent beside the vehicle are the practical alternatives.
What is the difference between an annex and an awning?
An annex zips to the underside of the tent and folds away with it, using the space directly under the tent. An awning attaches to the rack or tent base and stands on its own legs, so you can position it away from the vehicle and leave it pitched while the tent is closed. Forum users frequently describe a walled awning as an annex.
Final Verdict
For most owners, the annex is the single best annex-room upgrade available to a rooftop tent setup, and the decision comes down to your tent model rather than your budget. If you own an ARB Simpson III, the 804100 wins on owner history and warranty. If you own a Gen2 Overlander, the Smittybilt SB2588 is the strongest all-round pick with its 2000mm fabric and removable floor. TMBK, Bushveld II, Sirius 1 Plus, Delta Overland, Trailhead, XD Sherpa S4S, Cross 1200, Sky Ridge Pike 3 and Approach owners should match their entry above and ignore the rest.
Wedge and hardshell owners should expect a thinner shortlist than everyone else, and should plan around a side awning rather than wait for an annex that may never be made. Check your part number before you click, replace the supplied pegs, and let the room dry before it goes back in the bag. That is all the advice this category really needs, and it applies for 2026 and every year after.