Shelter for broilers on pasture with electric net

I am considering buying 6 freedom ranger chicks in several batches throughout summer and fall for freezer.  I have an electric fence for poultry that makes a circle and I want to move them around my acreage.  I also have 4 layer hens that are in a barnyard and coop and I think it best to keep the broilers separate.  If I have the electric netting on all the time, any suggestions on a house to keep them safe?  I want as simple as possible bearing in mind we have owls around here and I believe there have been raccoons down the road.  I want it easy to move and not that big as there will only be 6 birds in it.  Maybe it should be off the ground so they can go under it although they will have shade alot of time because of trees around property.  

I raise 100 freedom rangers at a time, so my scale is a bit different.  There are certainly racoons and owls in my area too.  My property is perimeter fenced, but even before that I didn't have issues with ground predators as long as the electric net was charged.  In spite of plenty of owls, hawks and eagles in the area I've only lost broilers to ravens.  Once I started keeping turkeys with the broilers that mostly stopped being a problem (I did lose 2 CRX to ravens this year, but they were also about to be culled anyway due to being unable/unwilling to move for almost any reason).  

For shelter I made an 8'x8' frame I think 18" tall that is covered with metal roofing panels.  It's all 2x2 lumber for the frame, so it's pretty light considering the size.  You could make something much smaller for just 6 birds.  2'x2' would be big enough for just 6 birds and pretty light weight.  You could certainly go a little larger if you wanted to and still be pretty light.  That will let them get out of the rain or sun when they want to, or hide from aerial predators.  Put a board in for a low roost of sorts and then they can get off the ground for sleeping if desired.  Move that 1-2 times per day and the manure will be nicely spread around.