Opinion by
Mr. Justice Elkin,
The answer to the question involved in this controversy depends upon whether there was proper service of notice of an intention to file a lien by a subcontractor. Section 8 of the Act bf June 4, 1901, P. L. 431, requires a subcontractor, intending to file a claim, to give the owner written notice to that effect. What the notice shall contain and when it shall be served are provided for in the statute, which also contains the following provision: "Service may be made personally on the owner anywhere; but, if. he cannot be served in the county where the structure or other improvement is situate, such notice and statement may be served on his architect or agent, or the party in possession of the structure or other improvement, and if there be no architect, agent or party in possession, it may be posted on the most public part of the structure or other improvement.”
In the present case there was no personal service upon the owner and this question may therefore be eliminated. There was service of notice upon the architect while in the city of Philadelphia outside of the county in which the building is located. In addition to the service upon the architect there was service in the county upon a person alleged to be in possession, and the appellants rely upon one or both of these services of notice as meeting the statutory requirements. The learned court below held *617that service upon the architect must be made in the county where the building is located and that service in Philadelphia was not sufficient. Appellants contend that service upon the architect may be made anywhere just as it can be upon the owner. This is a sharply defined issue and there is no decided case squarely ruling the question. The act does not provide for service upon the architect anywhere as it does in the case of the owner. In such cases it is important to keep in mind the fact that we are dealing with statutory liens against real estate. The proceeding is in rem and not in personam. The records of the county contain the information and data upon which the lien depends. It is true that an exact copy of the notice required by sec. 8 need not be set out in the claim, but such notice is an essential prerequisite to the filing of the lien and may always be inquired into upon the trial: Thirsk v. Evans, 211 Pa. 239. Service of this notice must be made in the manner prescribed by the statute, and failure to do so defeats the right to recover upon the claim filed. Inasmuch, therefore, as the lien is against the structure, the situs of which fixes the jurisdiction in which it becomes operative, it is but reasonable to hold that the legislature intended that the acts and things required to be done should take effect in the county where the building is located unless it is expressly provided that they may be done outside of the county. This is especially true as to the service of notice of an intention to file a lien. The act of 1901 does expressly provide for the service of notice upon the owner anywhere he may be found, but there is no such provision as to the architect, or agent or party in possession. The act provides that the service may be made on the architect, or agent or party in possession, “if he (the owner) cannot be served in the county where the structure or other improvement is situate.” It would do violence to the legislative intention as indicated by the language used to hold that service might be made upon the architect or agent anywhere. The architect, agent and party in possession are *618all coupled together in the same phrase and should be treated in the same way. It could scarcely be .seriously argued that the party in possession could be served outside the county, and, if he could not be so served, why should a different rule be applied to the architect or agent who stand upon the same statutory plane with respect to the service of notice? If the legislature intended to authorize the .service of notice upon the architect or agent outside of the county, it is not too much to require that it be done by language so plain as to leave no doubt about its meaning. We therefore hold that service of notice of an intension to file the lien upon the architect in the city of Philadelphia was not sufficient to meet the requirements of the act in this respect.
It is contended for appellants that there was service of notice upon a person in possession of the building. If such a service was in fact made, it would be sufficient. The proofs show that the notice was served upon a person in the building and the question to be determined is whether the person so served was “a party in possession” within the meaning of the act. This is largely a question of fact for the jury although when all the facts are ascertained it may be that the court would be warranted in saying that the service was not made upon the party in possession. It goes without saying that it is not every person in and around a building who may be regarded as a party in possession. However, in the present case appellants were denied the opportunity to prove the facts upon which they rely to show service upon a party in possession. The trial judge upon objection refused to admit many offers of testimony tending to establish the necessary facts. In this respect we think there was error. These offers were excluded largely on the theory that it was necessary to first establish the fact that the party served was in actual posesssion before proof of service and other incidental matters relied on could be admitted in evidence. Holding to this strict rule many of the offers were excluded. Evidence of this character must of necessity be introduced *619step by step. It might very well be that the testimony excluded in each offer would be insufficient standing alone to show service upon a proper person, but when supplemented by other evidence it might be sufficient to warrant a finding that service was made on a party in possession. At least appellants were entitled to prove all the facts tending to show that notice had been in fact served and that upon a party in possession. As we review the record this opportunity was not given appellants. As the record stands, with so many offers of testimony excluded, we cannot say as a matter of law whether the person served was a party in possession or not. Under these circumstances it will be necessary to reverse the judgment in order that appellants may be afforded an opportunity to prove their case. When the proofs are all in it will then be for the court or the jury, as the ease may be, to say whether the service of notice was made upon a proper person. These observations apply to the fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth and fourteenth assignments of error. In so far as any of these offers relate to service upon the architect, they were properly excluded, but they should have been received as bearing upon the question of service upon the party in possession. When the case is again tried all offers of testimony should be confined to the one question of showing service of notice upon a party in possession. In this connection it is competent to show what efforts were made to serve the owner, and why these efforts were not successful.
Judgment reversed and a venire facias de novo awarded.