Even if they don’t like to admit it, many trampers are closet hut baggers. Why not fess up, choose a range, and bag every hut? You might like to start with Tongariro or Abel Tasman national parks, both of which have less than 12 public huts each, enabling you to ‘collect’ them all in as few as two or three trips.
Other ranges with a low hut-density include the Kaimanawas (four public huts) and Victoria Forest Park (nine huts). However, even visiting this few huts will require multiday trips.
You could up the ante and take on one of the bigger ranges. The Kaweka Range boasts some 30 huts and bivs; visiting them all will take several trips and some imaginative detours. The Tararua Range has 50 public huts, and some of these (Carkeek for example) are quite remote by North Island standards.
The Holy Grails of the South Island are Fiordland and Kahurangi national parks (both with more than 70 huts) and in the North Island, it’s undoubtedly the Ruahine Range. With almost 70 public huts, this range is sure to occupy even the busiest tramper for several years. Top Gorge, Ikawatea and Taruarau are probably among the least visited.