Nesting Partner
Nesting is used to describe intimate partners that live (aka nest) together. Nesting partners are not always anchor or primary partners, and nesting partners do not always share funds. There can be more than one nesting partner. Nesting is not a permanent term but is assumed to be long-term.
Why "need"?
For some in the polyamorous community, hearing someone say they need a nesting partner sets off red flags. And while it is valid for them to be concerned - they must be conscientious of their response. Some people may need a live-in partner to help with bills, especially with the cost of living increasing. Some people have disabilities that require extra assistance in the home or will in the future. There are many reasons why someone may need a nesting partner versus want one.
Finances
Sharing a home with partners COULD decrease expenses if everyone is contributing. Those struggling against capitalism may need a nesting partner in the present (or future) to help pay rent. Sharing living expenses may give them a chance at saving money, paying other bills and debt, or simply not being at risk of homelessness. Having affordable housing is, unfortunately, a privilege. Of course, having a roommate could be the same, but an intimate partner may be willing to split expenses like groceries and share resources.
Disabilities
Some people need a nesting partner because of their disabilities. They may require assistance like help with bathing or medication administration. Having a live-in partner can increase accessibility and quality of life within their home. Seeking a partner that can double as a nesting partner may not always translate to assistance with disabilities or being a caretaker. It could lower their living expenses, and they could afford a home care nurse if they could not before. There is nothing wrong with PWD inserting a partner that is willing to help them in-home as a part of their health plan. In-home health care aides and aid are expensive. If a partner(s) is interested in nesting and helping their partner out in the home, it is well within their right to do and their decision should be respected. Some people would prefer any aid they received in-home come from a loved one.
Age
Humans age. Some polyamorists are planning ahead by saying they need a nesting partner. The elderly are often "forgotten" about and having a nesting partner can help with the potential issues attributed to aging. This is inclusive of failing health, falling, and mobility access.
Communal Living
Some polyamorists have been creating communal spaces for their polycule. For them, nesting together to share resources is crucial to keep their space thriving. Some people may be teachers for the children, some farmers; others may handle domestic labor. Their community may not all live together in the same home, but in the same concentrated area, like a compound. Investment in this space may be a requirement to date some people. While need may be a strong word to use, for them it is necessary in order to thrive.
To Each Their Own
Regardless of anyone's reasoning for why they need a nesting partner, it is not your job to change their mind or make them prove their needs to you. If you are unable or uninteresting in nesting with them, say that. It isn't inconsiderate to consider what works best for you. Some of you are already invested in nesting with someone else, don't like sharing spaces, or have different living standards. Nesting is a personal choice and has no direct correlation to commitment or validity of a polyamorous relationship.