Oui autant pour moi, je n'ai lu qu'après les posts qui étaient plus haut !
Je ne m'étais renseignée que sur le WWOOFing/HELPX en Australie, je pensais serieusement que c'était la même chose en nouvelle-zelande o_O !
Je me demandais si le HELPX nécessitait également un permis de travail en nouvelle-zélande et voici la réponse du site de l'immigration de la nouvelle-zélande (
Can I volunteer once I am in New Zealand? - Immigration NZ Knowledgebase):
Can I volunteer once I am in New Zealand?If you hold a student, visitor, or work visa you can volunteer, providing you will not receive any gain or reward for the activity you volunteer for i.e. a payment or benefit.
Any volunteer activity that work visa holders carry out must be over and above any paid work they undertake.
If you do receive any gain or reward, unless you have open work conditions on your visa, you will be in breach of your visa.
For example:
1. If you were required to wear a uniform as part of your role, and you were provided with that uniform by the organisation, you would not have received any gain or reward and would not be in breach of your visa.
2. If you were given a clothing voucher in exchange for your voluntary activity, then you would have received a reward and you would be in breach of your visa.
If your intention is to receive a gain or reward i.e. any payment or benefit such as board and lodging or goods (e.g. food, clothing and services) that can be valued in terms of money, then you are not considered to be a volunteer. Volunteers generally work for charities or not-for-profit organisations.
Please note that:
1. WWOOFing (Willing Workers on Organic Farms in New Zealand) is considered to be paid work, as WWOOFers receive food and accommodation. WWOOFers must apply for a work visa.
2. Non-paid on-the-job training before commencement of paid employment or non-paid work experience with commercial business is not regarded as voluntary work.
Please contact your nearest Immigration New Zealand branch if you require further information.
This answer was last updated on 4 December, 2012.
Heureusement, que la réalité est tout autre et que les hôtes ne demandent pas systématiquement votre VISA de travail....

, çà laisse un espoir !
Merci SarahLou pour avoir creuser la question