There is a great confusion about what an owner could do in the facade of the building.
Some owners consider that the part of the facade attached to your private property is also private, so you can change the colour of the facade that covers your private property and also you can install whatever you want as satellite dishes, air condition units, wires to dry off the clothes, etc.
Others consider that if your property is premises for comercial purpose you can even change the facade.
Finally, others, would think that you can do nothing without the unanimous consent of the community.
To clarify the situation we should say:
The facade is a common element, so nobody can change its configuration or aesthetic without the agreement of the general assembly.
The only exception is the part of the facade that covers the premises in the low floor, because it is mostly considered by the courts that this part of the facade is not communal, but private unless there are special infrastructure for the whole building.
Being communal the rest of the facade, nobody can do anything without the previous consent of the community. The community could take to court the owner paint the façade in a different colour or who install the air conditioning units or any other stuff in the facade without this consent. The only exception would be when this installation is necessary for the house and there is no other place to locate.
From 28 of June 2013, the new LPH reduces the quorum for this kind of agreements from the unanimity to an special majority ( 60% of the total owner and coefficients that are required now). It would be also necessary the licence from the Town Hall authorizing to do the works.
When we are approving something for all the owners, to get this 60% of the whole community ( Proprietors and coefficients ) the procedure is that the majority of the people in the general assembly agrees to approve and the people that are not in the meeting and do not oppose to the agreement in 30 days from the notification of the agreement will be considered as voting in favour of the agreement.
Let´s explain with an example: In a community with 100 Owners with a quota coefficient of 1% each, you would need 60 votes in favour, so supposing there are 15 people present or represented in the meeting and 10 of them vote in favour and 5 against, and from the 85 Owners that were not in the meeting, only 5 people notify to the community their opposition to the agreement in 30 days time, this means that the other 80 people will be consider to vote in favour. In this example the result of the votation would have been: 90 owners with 90% coefficient in favour ( 10 in the meeting and 80 from the absentees) and 10 against, so the agreement has been approved, with the 60% required.
On the contrary, when the agreement will be for the benefit of only one particular owner, the vote of the absent people could not count, so the 60% of the owners and quota coefficients of the whole community will have to reached in the general assembly. As it is not very common that 60% of the owners and coefficients attend a meeting, to avoid this problem that could make impossible to get the agreement, the solution is to approve the agreement for all the owners to do the same and in this way the agreement could not be considered particular but general, so the vote of the absent people could be taken as in favour after 30 days from the notification.