I know of many experienced tortoise keepers whose opinion, with all tortoise and turtle species, is that the best place for them is outside. I'm one to agree with this opinion (for the most part--I can get a bit paranoid when it comes to my tiny little Leopard!), and agree that, YES, building an outdoor enclosure for your redfoot is a very good idea!
You shouldn't need UVB lighting if you have him outside most/all the time, though I'd take a close look at the screen like Tiki suggested. Screening can block out a lot of that precious UVB, so you may even consider making the tort a pen out in the yard itself, with a wide-guage netting for the top. You don't need it to be so small to keep the tortoise in, considering it won't be climbing, just small enough to keep potential predators--dogs, cats, raccoons--out... The last outdoor enclosure I built, I just used a sturdy, inexpensive garden fencing. Flexible plastic material, with holes maybe 2" wide. Small enough to keep my beardies from squeezing out and the local stray cats from getting in, but not nearly a tight enough weave to keep that precious UVB out.
You may want to take the time to put a lip on top of the enclosure walls, just in case your little guy is adventurous and figures out how to climb! Also, things like plant pots make fantastic hides... I've never had a Redfoot, but with my Russians, they LOVE artificial burrows. Dig up a patch of dirt, put a plastic flower pot cut in half (lengthwise) in the hole at an angle, and bury it so just the top (entrance) is exposed. You get a nice, tight hiding place they can dig into, and if you get it in deep enough, they can still use the space on top, giving you maximum use of square footage. I'm using this hide method with my Russian group (planning on a few of them when it comes time to build the outdoor enclosure), and they love it... It's a little comical, watching all 4 try to squeeze in at once. :P
You can feed your tort for free, too, by housing him outside--get some good, edible plants to put in the enclosure (Hibiscus is a favorite!), plus the nice, edible weeds like Dandelion and Plantain, which you should already be able to find free in your own yard.
I don't know if you've come across Tortoise Forum at all, but they have an Enclosures forum where you can get some great ideas for your build. The address is http://tortoiseforum.org if you want to check it out.
As far as the beardie concern: As was said, parasites are a very real concern, and if you're going to have her outside, regular parasite checks are a must... Granted, many people would say the same thing even if she's indoors 100% of the time, considering crickets and the like can still carry parasites, too.
With temp, the ground can get pretty hot in direct sunlight, and you can temp gun the ground before taking him out to make sure it's warm enough. Throw a piece of slate down where it gets direct light, and keeping temps up should be non-issue... Even in the PNW, my last summer up there was my first with tortoises and one of the most mild summers I'd ever experienced, even so close to the coast, but, on that rare occasion when the planets aligned, and the sun came out and the temps managed to get above 70-ish, the slate paving stones I used in my tortoises' enclosures did a pretty good job of getting up above 90. Even on the grass, with air temps in the low 70s, temps could be as high as 85. From my understanding, just about everywhere else in the US regularly gets into the 80s during the summer, so, with the right provisions and regular monitoring, I don't think temps would be a big problem..
With the beardie, though, I'd have the same UVB concerns as the tortoise as far as the screened-in porch is concerned. But, even if you build just a basic little enclosure and put her out in the yard for a couple hours each day, or maybe one full day each week, something along those lines, it would still be very healthy for her and enough UVB exposure that you shouldn't need a UVB bulb on her indoor enclosure during the summer months.
(On a side note, I don't know about you, Aimee, but none of the beardies (granted, all adults) I've ever had will touch a 110 basking spot... They'll sit off to the side where it's a little cooler, but they seem to believe 110 is too hot. 100-105 seems to be the preference I've seen. The hottest I've temp-gunned any of them at before they felt the need to move to a cooler spot was about 100 which can be attained at cooler temps--they just have to bask longer... I've attained Beardie-friendly basking temps temps on light-colored bricks in air temps of 80-90, and on dark-colored slate in air temps of 70-80, so really not so hard to achieve outside. It takes some work and observation, sure, but so does anything with reptiles. Anyway, that's just my opinion, based on what I've observed with the 3 adults I've had.)