give me a word for a "nail household"

Might be a squatter.

In your final sentence, the word households in not appropriate. It is plural, and you want the singular, household.

I can think of no such word commonly used in the English language. A disgusted property developer (for whom i would have no sympathy) might call the householder a "hold-out," though.

Give me a word for a householder who/that [or a household that/which] refuses to yield their house to a property developer for a project unless they are paid a very large sum of money [for] as compensation.

A smart business person / a proud homeowner / a greedy [so and so] / a stick in the mud / ...

It all depends on whose perspective it is and what their reasons are, Fansy.