He rented a floor in his building for an Islamic centre, and they hold Friday prayers there and cause inconvenience to others

Firstly: 

We congratulate you for the deep faith that you possess. 

We offer you advice on two counts: 

-1- 

To the brothers who are running this Islamic centre: 

This conduct on their part is not acceptable and they have to
be fair to the owner of the building by paying attention to the following: 

1.One of the great principles
of Islam is that harm is to be avoided. 

It was narrated from Abu Sa‘eed al-Khudri (may Allah be
pleased with him) that the Prophet (blessings and peace of Allah be upon
him) said: “There should be neither harming nor reciprocating harm.”
Narrated by al-Haakim (2/57-58). He said: Its isnaad is saheeh according to
the conditions of Muslim. It was also narrated by Ibn Maajah (2340) from the
hadeeth of ‘Ubaadah ibn as-Saamit (may Allah be pleased with him). 

A type of harm that must be avoided is causing trouble to
others unlawfully. 

What the hadith means is: a man should not cause harm to his
brother, whether he initiates it or is responding in kind.

Al-Mugharrib fi Tarteeb al-Mu‘arrib [??] (8/2) 

Holding Friday prayers in the manner mentioned by the
questioner may lead to the rented offices being vacated and may be
detrimental to his livelihood and that of his dependents. 

2.It was narrated from Abu
Hurrah ar-Raqaashi, from his paternal uncle, that the Messenger of Allah
(blessings and peace of Allah be upon him) said: “V rily a man’s property is
not permissible unless he gives it willingly.” Narrated by Imam Ahmad in his
Musnad (34/299); classed as saheeh by al-Albaani in Irwa’ al-Ghaleel
(5/279) 

The scholars stated that taking a man’s wealth with the sword
of shyness (by causing embarrassment or taking advantage of his shyness) is
tantamount to consuming his wealth when he has not given it willingly, so it
is regarded as a kind of usurping. 

It says in al-Mawsoo‘ah al-Fiqhiyyah al-Kuwaitiyyah(18/263): 

The Shaafa‘is and Hanbalis stated that taking another
person’s property by means of shyness and embarrassment, such as asking
someone else for wealth in front of others, so that he gives it to him only
because he feels shy or embarrassed, or he gives him a gift out of shyness
or embarrassment, when the recipient knows that the giver gave it to him out
of shyness or embarrassment, does not mean that it becomes his property, and
it is not permissible for him to dispose of it. That which is taken by means
of shyness or embarrassment comes under the same ruling as that which is
usurped, and the one who took it is obliged to return it or offer
compensation for it. End quote. 

The owner of the building has not given approval or consent
for them to block the passageways or entrances which are meant for people to
pass through, or to use them as a place for shoes, and what is preventing
him from stopping them is shyness and feeling uncomfortable because of it
being an Islamic centre and a place where people pray. 

The brothers in charge of this centre have to pay attention
to that, and they should fear Allah with regard to the owner of the
building. 

-2- 

With regard to our advice to the owner of the building: 

You should adhere to the agreement that was made between you
and them with regard to the operation of the centre which was agreed upon,
until the end of the period agreed upon. 

With regard to Friday prayer, it was not mentioned in the
rental contract, so you have no obligation to give permission for it. But we
do not advise you at all to cancel it. Rather we advise you to come to an
agreement with them so that you can avoid the problems that you mentioned.
All of you have to pay attention to the fact that you are living in a
non-Muslim country, so you must be careful to avoid annoying and disturbing
the people, so that you can give a good impression of Islamic manners and
attitude, which will make it easier for you to call people to Allah. You
have to cooperate in righteousness and piety, instead of letting this
behaviour prevent people from making use of this Islamic centre or causing
trouble for the owner of the building and other tenants. We ask Allah, may
He be exalted, to put your affairs straight and to help you to do all that
is good. 

And Allah knows best.