Buttercup Farm Two Tier Birdhouse (small hole) Birdhouses Two Tier Birdhouse (small hole). 2 Tier Small Hole Birdhouse with shingle Roof for small birds. Dimensions: H48cm x W51cm x D27cm.. 2 Tier Small Hole Birdhouse for small birds. Comes with a shingle Roof.Dimensions: H48cm x W51cm x D27cm. Hole Dimensions Approx 6cm x 9xm. Buttercup Farm. TBBCo2TierSmallHoleBirdhouse. 0046737802807