In cases involving a common wall between shops, the principles derived from this judgment can be applied as follows:

1. Rights of Co-Owners: Each owner of the adjoining shops has an interest in the common wall and is entitled to use it reasonably for support and maintenance purposes. They may also raise the height of the wall or make structural modifications, provided such actions do not cause damage to the other owner’s property and are within the scope of reasonable use (!) .

2. Use and Modification of the Wall: Raising the height of the common wall or making structural changes is permissible if it is done without damaging the adjoining property and with the acknowledgment that the wall remains a joint property. Any such modifications should be reasonable and not amount to ousting or excluding the other owner from the use of the wall (!) (!) .

3. Right of Easement of Light and Air: The existence of a ventilator or openings in the common wall does not automatically confer a right of easement of light and air unless explicitly established through statutory provisions or agreements. The wall is generally considered a solid structure, and the right to open ventilators or windows in it is limited unless such rights are expressly granted or acquired (!) .

4. Damage and Damage Prevention: If a co-owner’s actions, such as raising the wall or constructing on it, do not cause damage to the other owner’s property, such actions are generally permissible. Conversely, any act that causes damage or threatens the structural integrity of the wall or adjoining properties can be challenged (!) (!) .

5. Finality of Findings: The determination of whether the wall is a party wall or an exclusive wall of a particular owner is a question of fact. Such findings are binding in subsequent proceedings unless shown to be perverse or otherwise legally flawed (!) .

In summary, in disputes involving a common wall between shops, each owner has a right to reasonably use and modify the wall for support and structural purposes, provided they do not damage the adjoining property. Rights of easement of light and air are limited unless explicitly established. The court's factual findings regarding the nature of the wall are binding, and actions that do not cause damage are generally permissible.