JUDGMENT Pankaj Mithal,J. Notice upon the respondent was directed to be issued by registered post AD as well as personally. The personal notice was not accepted by the respondent and was returned as is evident from the affidavit of service. The registered notice sent to the respondent was returned with the postal remark that on inquiry no person with the name of the respondent was found living in the said house. Notice as such was directed to be published in the daily newspaper Dainik Jagran. 2. Petitioner has filed affidavit of service annexing the copy of the Dainik Jagran dated 14.12.2010 wherein the notice of this petition was published fixing 3rd Jauntily 2011 as the next date. The original of the said newspaper has been produced by the counsel for the petitioner and is taken as part of the record. Inspite of steps taken by the petitioner for serving respondent by all the three modes as referred to above, no one till date has put in appearance on behalf of the respondent and filed counter affidavit. 3. In view of the above, deeming the service of notice to be sufficient upon respondent by publication, the court proceeded to hear the petition as ex-parte, having no other option. List has been revised. No one appears for the respondent. 4. I have heard Sri P.K. Mishra assisted by Sri Amit Singh, learned counsel for the petitioner. The challenge in the petition is to the revisional order dated 23.1.2010 passed by the Additional District Judge allowing rent revision no. 29 of 2009 ( Shiv Lal Gupta Vs. Nathu Lal Jaiswal). The dispute is about house no. 10/12 E-1 Khalasi Line, Kanpur Nagar. Petitioner is the owner and landlord of the said house which was let out to late Satya Narain Gupta, the father of the respondent. On the death of Satya Narain Gupta the tenancy was inherited by the respondent. The wife of the respondent acquired house no. 2/283 Nawabganj within the municipal limits of Kanpur city. At the same time, petitioner landlord acquired house no. 7/12Ambedkar Nagar Kidwai Nagar, Kanpur which was allotted to him by the U.P. Awas Evam Vikas Parishad, Lucknow. 5. In view of acquisition of the above two houses by the respondent and his wife, it was contended that the house in dispute is deemed to be vacant under Section 12 (3) of the Act. 6. 7/12Ambedkar Nagar Kidwai Nagar, Kanpur which was allotted to him by the U.P. Awas Evam Vikas Parishad, Lucknow. 5. In view of acquisition of the above two houses by the respondent and his wife, it was contended that the house in dispute is deemed to be vacant under Section 12 (3) of the Act. 6. Accordingly, house in dispute was declared to be vacant vide order dated 10.2.2009 and was ultimately released in favour of the petitioner on 22.6.2009. 7. Aggrieved by the above, respondent preferred a revision under Section 18 of the Act. The revision has been allowed by the impugned order dated 23.1.2010 on the ground that the release application under Section 16 (1) (b) of the Act can not be maintained simultaneously with the release application under Section 21 (1) (a) of the Act and that the house in dispute is partly in commercial use which aspect has not been considered by the authority below while allowing the release application. 8. The submission of Sri P.K. Mishra, learned counsel for the petitioner is that the house in dispute is of residential use and merely for the reason that a small part of it is being used as a sweet shop its nature would not change. There is no legal bar in simultaneously pursuing applications for release under Section 21 (1) (a) and Section 16 (1) (b) of the Act. 9. Section 12 of the Act provides for the deemed vacancy of building in certain cases. It provides that in case of a residential building if the tenant or any member of the family builds or otherwise acquires a residential building in a vacant state, the tenanted accommodation in his possession shall be deemed to be vacant. 10. Section 12 is a deeming provision. Therefore, a legal fiction has been created by it that despite tenant continuing to be in actual possession of the tenanted premises, if he or any member of his family acquires any residential building in vacant state in the same city, he shall be deemed to have ceased to occupy the building in his tenancy. In the instance case admittedly the respondent as well as his wife have acquired separate houses within the municipal limits of the city, in a vacant state and as such have ceased to have occupied the house in dispute. In the instance case admittedly the respondent as well as his wife have acquired separate houses within the municipal limits of the city, in a vacant state and as such have ceased to have occupied the house in dispute. In view of the above, the house in dispute is deemed to be vacant under Section 12 (3) of the Act. The revisional court has not set aside the order of vacancy but has only set aside the order of release on technical ground that the release application under Section 16 (1) (b) of the Act can not be maintained simultaneously with the release application under Section 21 (1) (a) of the Act. 11. There is no provision under the Act which bars the landlord from maintaining the release application both under Section 16 (1) (b) as well as Section 21 (1) (a) of the Act simultaneously. 12. The scheme of the Act permits filing of release application under Section 16 (1) (b) of the Act where the premises has been declared to be vacant for any reason, may be on account of its occupation by unauthorized person. The application under Section 21 (1) of the Act can be maintained by the landlord against the tenant, if the premises is bonafidely required by him for his own use or by any member of his family. The application under Section 21 (1) (a) of the Act is not maintainable against a person other than a tenant ie. an unauthorized occupant. Therefore, where the vacancy has been declared due to unauthorized occupation of the premises, a release application under Section 21 (1) (a) of the Act would not be maintainable but this would not debar the landlord from initiating proceedings under Section 21 (1) (a) of the Act where the occupant is not unauthorized and continues to be the tenant and the premises is deemed to be vacant as he has acquired an alternative residential accommodation in a vacant state within the city. In such a situation not only release application under Section 16 (1) (b) but also under Section 21 (1) of the Act would be maintainable. 13. Sri P.K. Mishra in this regard has placed reliance upon Sarla Devi (Smt.) Vs. Pushpa Agnihotri (Smt.) 2008 (2) ARC 725 . In such a situation not only release application under Section 16 (1) (b) but also under Section 21 (1) of the Act would be maintainable. 13. Sri P.K. Mishra in this regard has placed reliance upon Sarla Devi (Smt.) Vs. Pushpa Agnihotri (Smt.) 2008 (2) ARC 725 . In the said case also a vacancy was declared under Section 12 (3) of the Act and a release application under Section 16 of the Act was filed. The land lord had availed the remedy of Section 21 (1) (a) of the Act also. This Court refused to accept the contention of the tenant that release application under Section 16 (1) (b) of the Act is not maintainable and it was held that the landlord has a right to file application both under Section 21 (1) (a) of the Act and to get the premises declared vacant under Section 12 (3) of the Act. 14. In view of the above, it is held that petitioner is entitle to maintain release application both under Section 21 (1) (a) of the Act as well as under Section 16 (1) (b) under the facts and circumstances of the present case. 15. The nature of the use of the house in dispute is not of much relevance. It is admitted to the parties that house in dispute was let out to the father of the petitioner for the residential purpose. In case the outer room of the said house is used by the tenant without permission of the landlord as a shop for selling sweets, it can not alter the nature of the house in dispute. 16. Moreover it is settled that the dominant purpose of the use of the building has to be considered in determining the nature of its use. Since the house in dispute was let out for residential purpose and is admittedly being used in part for residential purpose, it will continue to be of residential use. In view of the aforesaid facts and circumstances, the revisional order dated 23.01.2010 is unsustainable and is hereby quashed. The writ petition is allowed.