The central legal point established in the judgment is that the breach of a legal duty, whether arising from contract or other factors, can justify the grant of a perpetual injunction under Section 54 of the Specific Relief Act.

( 1 ) IN 1938, the appellant Parul Bala Roy Choudhury purchased from the Calcutta Improvement Trust a plot of land No. 881 of Scheme No. 33 covering an area of 5 cottas 13 chataks and 25 sq. ft. While she was the owner of the whole of the plot, she submitted a building plan for sanction by the Calcutta Corporation. The plan was sanctioned by the Corporation on 15-5-1939, This plot viz: 381 is a corner plot abutting on two 40ft. wide streets made by the Calcutta Improvement Trust. The greater length of the plot is north to south. One face of the plot, namely, the northern one, abuts on one 40 ft. road and west face of the plot on the other 40ft. road. The plan which was submitted for sanction and which was sanctioned by the Corporation showed for the purpose of the building the frontage of the plot to be on the northern road. An open space was left at the farthest end opposite to this road and at the back of the proposed building, that is to say, the open land was shown to be the southern part of plot No. 381. This open space was 87ft. and odd wide from north to south.

( 2 ) AFTER obtaining this sanction, the appellant sold the southern portion of plot No. 381 to the respondents. The area so sold was 2 cottas 2 chattaks 8 sq. ft. and it was 33 ft. north to south, with the result that the open back space which was retained by the vendor at the back of her proposed building on her own site was 4 ft. wide. We are using these figures for the purpose of convenience, for in fact the open space so retained by the vendor was 4 ft. wide, at some places and 4ft. 6 inches in others and the plot sold to the respondents was 33 ft. wide at some places and 33 ft. 5 inches at other places. But that is not very material. We only mention these details in order to be more accurate.

( 3 ) AFTER the sale, the respondents submitted a plan for building upon the site so purchased by them. The Corporation refused to sanction that plan, one of the grounds being that the building proposed by the respondents had utilised a portion of the open ground, a portion of which had been shown in the plan sanctioned in favour of the appellant on 15 5-1939, to be the back space of her proposed building.

( 4 ) FOR the purposes of understanding the position, we will have to notice some of the Rules mentioned in Sch- XVII of the Calcutta Municipal Act in [3] of 1923. Section 319 of the said Act enacts that no piece of land shall be used as a site for the erection of a new building, and no new building shall be erected, otherwise than in accordance with the provisions of that Chapter and of Sch. XVII and any orders, rules or by-laws made under the Act, relating to the use of building sites or the erection of new building, as the case may be. Schedule XVII is a part of the Act itself. The relevant rules for regulating "domestic houses", as defined in Section 3 of the Act are Rules 30, 32 and 36. We may say that both the building plans, the plan of the appellant which had already been sanctioned, the plan submitted by the respondents, the sanction of which has been refused by the Corporation, are for raising dwelling houses, that is to say, a species of domestic houses.

( 5 ) RULE 32 relates to open side spaces. It says that certain amount of open space must be kept at the sides of buildings. Ordinarily, it ought to be 6 ft. wide for each building, but if there is an open space within the site of the neighboring building, 2 or more ft. in width adjoining to that relevant side of the proposed building, then the open space can be reduced to 4ft. wide. According to this rule, if there had not been anything else in this case, the respondents would have had to keep on the facts of this case, an open side space of only 4ft. wide on the northern part of their site.

( 6 ) RULE 30 deals with the open back space. First of all, a back space is defined to be the space within the site of the proposed building opposite to the street on which the side abuts,