The statute (G.L.c. 188, §1) provides that a homestead can be acquired by the owner "or one or all who rightfully possess the presmise (sic) by lease or otherwise." The quoted language would seem to indicate that one holding an estate of possession only (lease or life interest) could be a declarant. But let's see.
The only case that really sheds any light on the subject is Assistant Recorder of the North Registry District of Bristol County v. Spinelli 38 Mass.App.Ct. 655, 651 N.E.2d 411 (1995), wherein Lydia Spinelli held title as trustee and as such declared a homestead on property that she as a beneficiary of the trust possessed as her principal residence. The court said that she was not eligible to declare a homestead as trustee simply because "the homestead statute does not provide for the application of the statute to property held in trust."
Spinelli also raised the argument that she was in possession of the property and as such was eligible to declare the homestead. The court quoted from Thurston v. Maddocks, 6 Allen 427, 428 (1863), where in connection with an earlier homestead statute the court had said that an "estate in which a homestead may exist is such as is conveyed by deed," and noted that "Spinelli's interest in the property arises by virtue of her beneficial interests in the trusts [and] these interests can be transferred without the necessity of any deed."
1 The statute at one point states that the "owner or owners" can acquire the homestead, but in a subsequent sentence states that "only one owner can acquire an estate of homestead." This inconsistency has been interpreted to mean that if there is more than one owner only one of them can be the declarant. Dwyer v. Cempellin 424 Mass. 26, 673 N.E.2d 863 (1996).