This is a difficult situation for sure, one which could be quite complicated, not to mention it has the potential to cause a great deal of turmoil within your family.
When you say that this is a "family" cottage, who is actually on title for the property?
How many family members own and share the property?
Is there a formal agreement between all of the parties with regard to the property, it's usage, individual's obligations etc
The determination of whether it is a permanent structure or not would be difficult. It may be on blocks, however could it be easily moved, removed or relocated? A trailer or portable structure can be towed or dragged from one location and moved to another. This may not be possible with this Bunkie, even though it sits on blocks.
If the entire family has the use of the property, then that would generally extend to all buildings etc on the property.
Was there an agreement with the other family members who have an interest in the property in relation to this Bunkie prior to it being built?
My concern is that if the other family members chose to have the building removed or demolished, they may be completely justified and entitled to do so based on a majority decision. This is the difficulty of jointly owning property. Generally, any decisions on the property, such as adding a structure, must be agreed upon by all parties
If there is no agreement between the parties with regard to the usage of the property, and it is simply understood that the cottage property is for the use of family, however many people that may be, then you as an individual really have no right to deny access to this building to any family members as they have a right to use the property and any structure found thereon.
This building is different from your car, or a private trailer you bring to the property.
It is not readily movable, as a trailer would be
If you built this of your own accord, without the consent of the other interested parties, then they would have no obligation to pay for any portion of it, and could actually insist on the removal of it at your expense.
If you can provide some more background behind the manner in which the property is owned/shared etc, this would be very helpful in providing further guidance
The cottage belonged to my mother and when she passed away in 2011, my two sister and I inherited the property.
There was no formal agreement made up in regards XXXXX XXXXX of the cottage.
It was built before my mother passed away so the consent of my sisters was not needed at the time.
Can I demand expenses for the cost of building it?
Is there any way for me to force the sale of the cottage?
We are tenants in common, each owning one third. I know we are equally responsible for expenses and upkeep but the use is not limited. If I added my children's names to my third, would we be able to make a majority decision regarding the bunkie and make sure it's not torn down, if it came down to that?
If it's the way you're describing, I certainly don't want them to be able to hold anything over our heads.