Bigger is always better when it comes to cage sizes, and C and C cages are best when it comes to cages. Don't try to make a C and C cage to RSPCA cage sizes as C and C metal grids are 35 cm square, not 30 cm. plus they have a gap between them when put together. 4 x 30 = 120. 4 x 35 = 140. Thus you cannot make a C and C cage to the same size as a shop cage, and neither should you. They are never anywhere near big enough for 1 piggie, never mind 2.