Subscribe Contribute Advertise Facebook Twitter Instagram Forums Newsletter

Big Agnes Seedhouse SL3 Tent REVIEW

A lightweight double-wall three-person tent with full storm protection and great views - but is it really sized for three?

Print Jump to Reader Comments

by Doug Johnson | 2006-11-21 03:00:00-07

Big Agnes Seedhouse SL3 Tent REVIEW


The Big Agnes Seedhouse SL3 is among the lightest double wall, three-person tents on the market. It offers excellent views with the fly removed, full rain protection, and thoughtful design features. But how is the sizing for three adults?

What’s Good

  • Lightweight for a three-person double wall tent at just over 4 pounds
  • Good separation between inner tent and fly
  • Center pole greatly increases usable space
  • Quick and easy set up
  • Three well-placed interior pockets
  • Fantastic bug-free views with the fly removed

What’s Not So Good

  • Sized more like a 2.5 person tent
  • Lack of a vent leads to condensation inside the fly
  • Small vestibule
  • Rainfly storm flap snags in the zipper and is easily damaged



2006 Big Agnes Seedhouse SL3


Two-person double wall tent


Fly is 20d silnylon ripstop with a 1200 mm waterproof polyurethane coating, body is 20d nylon mesh, floor is 30d ripstop silnylon with a 1200 mm waterproof coating

  Poles and Stakes

DAC Featherlite NSL pole system - GREEN anodized 8.2 mm poles with press-fit connectors and lightweight hubs; 10 aluminum alloy square stakes 7.0 in (18 cm) long, 0.4 oz (11 g) each, 10 guylines with adjusters 0.1 oz (3 g)


Floor length 90 in (229 cm), width 58/73/51 in (147/185/130 cm) height 46 in (117 cm)

  Packed Size

20.5 in x 7 in (52 cm x 18 cm)

  Total Weight
As supplied by manufacturer with all included items

Measured weight 4 lb 8.8 oz (2.06 kg), manufacturer specification 4 lb 8 oz (2.04 kg)

  Trail Weight
Includes minimum number of items needed to erect the tent

Measured weight 4 lb 2.9 oz (1.90 kg), includes tent body, fly, poles and three stakes

  Protected Area

Floor area 36.0 ft2 (3.3 m2)

  Floor Area/Trail Weight Ratio

8.6 ft2/lb based on 36.0 ft2 floor area and trail weight of 4.18 lb




Aluminum poles $35, 9.6 oz (272 g); footprint $32, 8.8 oz (249 g)


The Big Agnes Seedhouse SL3 is the larger version of the Big Agnes Seedhouse SL2. It is a double wall tent with a full mesh inner tent and a lightweight silnylon rainfly. Like the SL2, the SL3 features a single shock-corded ridge pole with dual hubs. In addition, the SL3 includes a second pole that crosses the middle for increased usable space and separation between the inner and outer tents.

At 4 pounds 2.9 ounces (trail weight), the Big Agnes Seedhouse SL3 is one of the lightest double wall, three-person tents on the market. However, at only 36 square feet of floor space, it is tight for a three-person tent. Fitting three full-size adults in the SL3 requires that one person be facing the rear of the tent and that full-length sleeping pads overlap at some point. The vestibule is also too small to store three packs and still be able to enter and exit the tent. With this in mind, I would call the Big Agnes SL3 a “2.5-person tent”; it would be fine for a family of three that includes a young child and is very comfortable for two adults and gear.

Big Agnes Seedhouse SL3 Tent REVIEW - 1
The Big Agnes SL3 is tight for three full-size adults.

Setting up the SL3 is very quick and can easily be done in just a few minutes. The main pole is deployed first and inserted into grommets at the corners of the inner tent and then attached with plastic clips. The middle pole is then attached to mid-point grommets and attached with plastic clips. The two poles do not connect at their intersection. On its own, the inner tent is freestanding and requires no stakes.

Big Agnes Seedhouse SL3 Tent REVIEW - 2
An attachment to link the poles at the center junction would help with wind stability and snow loading.

The rainfly is pitched by attaching six snapping buckles at the base of the tent and then adjusting for equal tension. Two stakes at the front and one at the rear are all that are needed for a minimal setup with the fly. There are a total of six stakeout points on the inner tent and eleven on the fly for a grand total of seventeen.

Big Agnes Seedhouse SL3 Tent REVIEW - 3
The rainfly is attached with six snapping buckles and secures with three stakes.

The inner tent of the SL3 is made entirely of 20 denier nylon mesh with a 7.5 inch high bathtub floor. With the rainfly off, this tent offers complete 360 degree views, one of the best views I’ve ever seen in a tent. This was especially nice during nights with heavy bug pressure; after using mainly single wall tents for quite a while, the expansive views while hiding from mosquitoes was a wonderful change. While the mesh of the inner tent gives the impression of being fragile, no damage occurred during field testing.

Big Agnes Seedhouse SL3 Tent REVIEW - 4
The SL3 without fly offers excellent views and a great refuge from bugs.

Internal storage of the Big Agnes tent is excellent. There is a wide pocket above the door and another pocket on either side of the door. The use of mesh makes it very easy to see individual items and there is plenty of room for cameras, headlamps, sunglasses, etc. Despite stuffing the pockets, we never experienced any snags or tears in the mesh fabric.

Big Agnes Seedhouse SL3 Tent REVIEW - 5
A large upper pocket (shown) and two lower pockets are great for organization.

The silnylon rainfly and generous bathtub floor offer full rain protection during downpours. While I didn’t experience snow loading with this tent, when we reviewed the Seedhouse SL2, it held up nicely to several inches of snow. With the middle pole in addition to the ridge pole, I would expect that the SL3 would have similar, if not better results than the SL2.

When camping in moderate winds at the treeline, the SL3 showed solid wind stability. By using the guylines that are midway up the fly, the tent experiences very little side to side movement. However, the rainfly does not attach to the poles at these points so the fly pulls away from the tent structure. While this is common in three-season tents, attachment points like this help a great deal with wind stability. Further, the middle and ridgeline poles do not attach at their intersection, instead they “float” independently of each other. In heavy winds, it would be nice to have the option of locking those together (although it would be very easy with a Velcro strap). With its generous guyouts, steeply-sloped front and rear, and good pole structure, the SL3 handles moderate winds very well. With some modifications (Velcro strap at the intersection and sewn-in Velcro attachments at the upper guyout points), it would be able to handle very high winds.

Headroom in the SL3 is very good - especially in the middle of the tent. I’m 6 feet 1 inch tall and I have plenty of room to sit up and stretch out, even with another hiker in the tent. The door area is much lower however, and requires bending over to enter the tent. With the rainfly attached, entry into the tent is even harder. A larger entryway or a second door would be a welcome addition, especially in a three-person tent.

Big Agnes Seedhouse SL3 Tent REVIEW - 6
While the height in the middle of the tent (left) is comfortable for a tall hiker to sit up, the entry (right) is much more cramped.

With the mesh inner tent and good separation between the inner and outer tents, I never experienced condensation inside the inner tent during field testing. However, I experienced quite a bit of condensation on the inside of the rainfly. This is due to restricted airflow.

The best ventilation systems in tents tend to use a “high/low” system of venting in which air flows from a lower vent through a vent up high, creating a chimney effect. While an overhang at the rear of the SL3 allows for the low part of that system, the lack of an upper vent traps air under the fly. While this is not a huge problem due to the double wall design (and the ability to carry the rainfly separately from the inner tent), a high vent on the rainfly would significantly increase airflow, ventilation, and condensation resistance.

Big Agnes Seedhouse SL3 Tent REVIEW - 7
An overhang at the rear of the fly helps with airflow and ventilation.

While I didn’t experience any durability problems with the inner tent, the rainfly was damaged by an overzealous hiker. The storm flap of the rainfly tends to get caught in the zipper. This is definitely annoying and makes it difficult to quickly close the rainfly. With practice, though it isn’t too hard to separate the two when zipping. One night, however, a hiking buddy experienced this problem and forced the stuck zipper along, tearing the fly. While this was obviously hiker error, I took this as an opportunity to look at Big Agnes’ customer service. They were wonderful and had a completely new fly out to me within a week. While you shouldn’t experience a similar problem, it is nice to know that Big Agnes stands behind their products with integrity.

Big Agnes Seedhouse SL3 Tent REVIEW - 8
The front storm flap snags easily in the zipper and was damaged by an overzealous hiker during testing. Although this was due to user error, Big Agnes quickly replaced the entire rainfly.


The Big Agnes Seedhouse SL3 is an excellent double wall tent. However, the small door, small vestibule, and limited interior space make it pretty cramped for three adults. But if you think of it as a 2.5 person tent (two adults plus gear), it quickly moves to the head of its class. This is a great tent for a family of three or two hikers looking for extra room.

What’s Unique

The full mesh inner tent makes for excellent views during heavy bug pressure.

Recommendations for Improvement

The biggest improvement to the Big Agnes Seedhouse SL3 would be a name change to the SL2.5. To be a great three-person tent it would need:

  • Several more inches of width
  • A larger door (or a second one)
  • A larger vestibule

Beyond that, my recommendations are minor:

  • For increased wind stability, pole attachments at the upper guyline attachments and a connection at the pole junction would be nice, but are probably beyond the scope of this three-season tent.
  • A reinforcement of the storm flap on the rainfly would also be nice - if only to avoid damage caused by heavy-handed hikers.
  • An upper vent on the fly would really help with ventilation.


"Big Agnes Seedhouse SL3 Tent REVIEW," by Doug Johnson. (ISSN 1537-0364)., 2006-11-21 03:00:00-07.


Reader Comments

You must login to post comments.

New Visitors: Create a new account
Remember my login info.

Big Agnes Seedhouse SL3 Tent REVIEW
Display Avatars
Sort By:
Benjamin Smith
(bugbomb) - F - M

Locale: South Texas
Big Agnes Seedhouse SL3 Tent REVIEW on 11/21/2006 20:14:14 MST Print View

Companion forum thread to:

Big Agnes Seedhouse SL3 Tent REVIEW

Brian James
(bjamesd) - F

Locale: South Coast of BC
space on 11/23/2006 17:55:56 MST Print View

I've been using this tent since the spring... my GF has claustrophobia issues (and camping dislike issues) so I went with the biggest tent I could still carry myself.

For three it's tight, but then again this is an UL tent... The vestibule is tighter than some as well, but I can't help but wonder if the complaint would have been in the other direction?

I find the tent to be "just right" sized for 3 ULers, and "just right" sized in terms of vestibule as well. (Being a Canadian I don't cook in shelters.)

The greatest criticism I have of the tent's air volume. It's cold! Something that hadn't occurred to me when buying it is that there's so much air volume that it's hard to warm up with your body. The space is of course absolutely joyous when changing clothes or in the rain.

But if you use it with 1 or 2 people in sub-freezing temperatures, remember that it's effectively a single-wall tent (being all mesh inside) with a large amount of volume.

Another neat feature is the option of setting it up with the footprint and no inner tent. That makes it a 3-lb 3-person freestanding shelter that's strong enough in shape and material to be used below the treeline in winter. Now that's versatility...


Edited by bjamesd on 11/23/2006 17:57:11 MST.

Brett .
(Brett1234) - F

Locale: CA
re:Big Agnes Seedhouse SL3 Tent REVIEW on 11/23/2006 22:18:09 MST Print View

Thanks for your comments. Have you used the tent in hot/humid or cold/humid conditions? It has no roof peak vent that I can see, and that has been a recipe for uncomfortable heat and humidity and condensation in my experience. Do you notice high levels of humidity which could vent if there was only a roof vent? I am returning my Sierra Designs Lightning to REI for just that reason, and replacing it with a HalfDome2HC.
By the way, please explain, "I am Canadian so don't cook in my tent"??

Brian James
(bjamesd) - F

Locale: South Coast of BC
Re: re:Big Agnes Seedhouse SL3 Tent REVIEW on 11/24/2006 12:52:44 MST Print View

Re: hot/humid, I think that your definition of those terms would depend on your location. Here in south coastal BC (=the same region you call the Pacific Northwest) we get the kind of humidity that can cause condensation in any tent made. Just above-freezing, completely still, utterly moisture-saturated air that alternates between spitting light rain and hanging fog is quite common. In those conditions I've had condensation and I've wished for a peak vent.

I do find it to perform quite well for three reasons:

1) the inner wall is bug netting so any occasional drip from the ceiling would hit the netting and run off

2) (this is the main thing) The fly can be staked very high off the ground on either side -- or all the way around. This allows the lightest of air movements to bring fresh air into the tent. It's airy to the point where I have to be careful to stake it *low* on sub-zero nights because otherwise it becomes a forced-air deepfreeze...

3) The tent's "substitute" for a peak vent is a double-zipped door that zips very close to the high point of the tent. Thus on any night where you don't have a heavy vertical downpour or driven precipitation coming from all sides, you can crack the top of the door and let convective heat carry the condensation out.

I don't want to sound like a fanboy for the tent. I've had condensation in the SL3 but not often, and that's pretty good for the conditions I've used it in so far.

Now that we have (yards of) snow and a nice cold snap I'm looking forward to pitching it in "fast-fly" mode in a snowbank somewhere to see how it performs at -10C or so. I also have a cool Clikstand prototype that I'm reviewing... :D

RE: cooking in tents in Canada, the bear situation is quite a bit different up here. Based on the stories I've read about bears down south, it seems that *in general* our bears are bigger, wilder, and more predatory. I don't know about the east but in Western Canada we lose recreationists, forest service workers, and other professionals who work in bear country every single season. I've personally been hunted by a grizzly while in a group of 4... I've also walked up a cutline all morning, and then turned around in the afternoon to return and found black bear footprints in mine for a long way.

It's not like we're running the gauntlet every time we go hiking, but we are generally *very* careful about bear awareness. Cooking within 100 yards of a campsite would be very embarrassing and offensive to other campers, as is keeping any food or cooking equipment anywhere near your campsite at night. Or at ground level for that matter.

I know guys who've been going outdoors all their lives, and they think I'm an idiot for going hiking without a rifle. Farther North in BC and Alberta the bears stand 12' tall and you supposedly wouldn't want to take a crap without a rifle across your knees... I stick to bear spray and staying alert!

Edited by bjamesd on 11/26/2006 11:21:12 MST.