It has been decided by this court in several cases that, if a man builds a house on land which is not his own, by consent of the owner, the house is personal property. Wells v. Banister, 4 Mass. 514. Doty v. Gorham, 5 Pick. 487. Ashmun v. Williams, 8 Pick. 402. First Parish in Sudbury v. Jones, 8 Cush. 190. Belding v. Cushing, 1 Gray, 578. It remains separate from the freehold by virtue of the agreement between the parties. As the agreement relates to personal property, it may be made by paroi.

Assuming, then, that the dwelling-house in question was personal property when it was first erected, the defendant contends that it did not remain so, because Connor, the owner, authorized the defendant by paroi to mortgage it to Williams with the land, to secure money which Williams had advanced to Connor towards building it; and because a mortgage was made in pursuance of this agreement.

There is no reason why a paroi agreement of Connor to this effect should not be equally valid with a verbal agreement that he should have the house as personal property. The effect of it would be to affix the house to the land and make it a part of the realty, so far as the mortgage was concerned, and Williams would hold it accordingly.

To this the plaintiff replies that the defendant is a stranger to the title of Williams; that Williams is not a party to this suit, and may never set up his title, and the defendant cannot set it up in his behalf. If it were true that the defendant had no connection with the title of Williams, it would follow that *188he could not set it up in defence of this suit. But the mortgage was made by the defendant, and contains covenants of warranty, so that the defendant is bound to Williams to defend his title, and he has given his own note for the amount due to Williams. He cannot, therefore, be regarded as a stranger to the title, and may avail himself of it. The jury should have been instructed that if they were satisfied, upon the evidence in the case, that Connor agreed that the defendant might make the mortgage to Williams and that the house should be included in the mortgage and pass by it with the land, the house would by virtue of such agreement pass with the land, as a part of the realty, and the defendant might in this action avail himself of the agreement.

We have regarded the fraudulent sale of the house by Connor to Riddle as an immaterial fact. It would pass no title to Riddle as against Connor’s creditors; but on the other hand it would not prevent the house from passing to Williams by the mortgage. The two transactions were independent of each other.

Exceptions sustained.