Possessory protection against erection of a wall and visual screening between neighbours: co-possession, lack of delimitability of possessory spheres and lack of excessiveness of the immission; appeal dismissed

Facts

The parties are owners or neighbours of two plots of land situated on a slope in U. (Aargau), each built upon with a terraced house. The upper plot (originally owned by D.) holds, to the detriment of the plot of the respondent C., a right to build over: the roof of the lower residential house serves the upper residential house as a terrace. This is enclosed by a half-height wall (so-called Aufmauerung), which structurally appears as an extension of the external facade of the lower residential house beyond the roof edge.

Under the easement agreement of 30 August 1978, the owner of the upper plot was to place immovable planters on the terrace so that the view onto the lower seating area was blocked (Clause VIII). D. removed the dense, up to 2.5 m high evergreen bushes and replaced them with planters around 40 cm high, either unplanted or loosely planted. C. thereby lost the visual screening; moreover, there was a risk of falling.

In 2014 C. had green metal posts installed on the external wall of her residential storey, projecting about 100 cm above the floor of the upper terrace, in order to erect a fall guard and visual screen. The District Court of Baden provisionally prohibited C. from continuing the construction work and set D. a deadline to initiate main proceedings. D. sued for an injunction and removal, as well as restoration of the terrace. The proceedings were stayed pending a building law procedure. The Municipal Council of U. by decision of 2 November 2015 obliged D. to install a fall protection and prohibited him, until then, from using the terrace; the legal remedies were dismissed up to the Administrative Court. On 3 July 2017 the Municipal Council found that the fall protection had been properly installed.

The District Court of Baden fully granted D.'s action on 16 November 2017. It examined who is the possessor of the building facade to which the posts were attached. C. lodged an appeal with the Cantonal Court of Aargau. Between the judgment and its notification, D. sold the plot on 13 December 2017 to A.A. and B.A., who entered the proceedings. The Cantonal Court granted the appeal on 11 December 2018 and dismissed the action (ZVE.2018.44).

A.A. and B.A. filed a subsidiary constitutional complaint and a civil law appeal with the Federal Supreme Court by submission of 18 February 2019, requesting that their action be granted in accordance with the first-instance decision, or alternatively that the matter be remitted. The Federal Supreme Court did not obtain any responses; the application for suspensive effect was dismissed.

The subject matter of the dispute is possessory protection (Art. 926 ff. CC) and neighbour law (Art. 684 CC).

Considerations

1. Admissibility The threshold amount in dispute of CHF 30,000.-- (Art. 74 para. 1 lit. b FSCA) is not reached, as the amount in dispute is CHF 20,000.--. The exception for a legal question of fundamental importance (Art. 74 para. 2 lit. a FSCA) does not apply, since possessory protection judgments are only provisional regulations and count as provisional measures (Art. 98 FSCA). The submission is treated as a subsidiary constitutional complaint, by which only the violation of constitutional rights may be asserted (Art. 116 FSCA), under the strict principle of complaints (Art. 106 para. 2 FSCA). Arbitrariness in the establishment of facts and in the application of law is only assumed where there is manifest untenability.

2. Violation of the right to be heard The duty to give reasons (Art. 29 para. 2 Cst.) has not been violated. The Cantonal Court did not have to refute every argument; it proceeded from co-possession, which excludes sole possession, and gave its decision a detailed statement of reasons, so that the appellants could contest it appropriately.

3. Possessory protection versus right in the thing In possessory protection proceedings, only the actual control is decided, not the lawfulness of the condition or the right in the thing (Art. 927 f. CC). The holder of an easement may also claim possessory protection; what is decisive is the previous actual exercise and not the content of the easement. Arguments of the appellants based on the right to build over, co-ownership (Art. 670 CC) or ownership of the Aufmauerung are inadmissible or miss the point.

4. Co-possession of the Aufmauerung Co-possession in the narrower sense exists where several persons can each individually exercise factual control without the cooperation of the others; simultaneous exercise is not required. The Cantonal Court was entitled, without arbitrariness, to assume that the Aufmauerung serves to delimit the appellants' terrace and at the same time forms the closure of the respondent's external facade, which is why both parties have co-possession. New facts (on the function of the Aufmauerung without use as a terrace) are disregarded (Art. 99 para. 1 FSCA).

5. Delimitability of possessory spheres Possessory remedies against co-possessors in the narrower sense are only admissible if the possessory spheres can be clearly delimited and the legal relationship between the co-possessors is not to be resolved. The appellants have not shown any use of the external wall of the Aufmauerung that excludes the respondent; their submissions rest on legal arguments or on an incorrect assumption of sole possession.…