I’d like to build or buy hutches that give each of my rabbits 25 square feet or so. Do you know of anywhere I could buy these for not crazy prices or find plans to build them myself?

As the title says, have an admittedly overweight doe with a peanut sized mass on her side. It moves with her skin and is relarively firm and roughly spherical. Does not appear to be fluid filled or have any associated wound. Fur is on it like the surrounding skin. Does not appear to be painful for her. Would post pictures but not much to see under the fur and is not noticeable unless you feel.

Is this a cause for a vet visit? Or is it a threat to the rest of the colony? She is cohoused with three other Does. ​​

My plan is to take 12"x12"x2" concrete blocks, and 2/3 bury them for a perimeter, so I'll have 4" above and 8" below ground to stop things from digging in our out. 10'x10' area with rabbit wire fencing around it. The back will be a lifted platform of pallets I have, and 3 upside down totes for homes for the 2 does and the buck. Each corner will have 8 foot post (buried two feet) about 1 foot out diagonal from the corner. Will string a 12x12 tarp over the whole thing (with about 1 foot of overhang to try and help keep out more water as it rains a lot). It's on a hill with a moderate slope (maybe 18" over the 10 foot run) so the rain should naturally run down and away from the rabbits. Due to city ordinances I can't have more than 10 rabbits at a time so I'll cull the litters to make sure I stick to that. If the buck gets to be a problem I considered building a wall within the fence and sectioning him off to like a 3'x7' area, but hopefully they'll have enough room to get along.