Praise be to Allah.
This message contains fabrication about Allaah and claims to know that which is known only by Allaah. How does he know that the house that is built in Paradise for its owner will be overlooking the Throne of the Most Merciful, the palace of the Messenger (blessings and peace of Allaah be upon him) and the river of al-Kawthar?
The Throne of the Most Merciful is the roof of all creation and is above all creation, so how can this house be overlooking it?
The Prophet (blessings and peace of Allaah be upon him) encouraged some deeds and promised houses in Paradise to those who do them, but he did not give details of their location or what they overlook.
Moreover, this kind of message is a kind of foolishness which the scholars have pointed out and warned against being tempted to publish them, such as that message which describes the number of rak’ahs of the prayers as a phone number to contact Allaah, may He be exalted -- Allaah forbid -- or that in which they liken the Hereafter to a journey on an airline with tickets, seats and other foolish things; and the pamphlet in which there is information about the Prophet (blessings and peace of Allaah be upon him) and they call it the passport of the Prophet or the ID card of the Prophet! All of that is a waste of time and money, and may also be a kind of mockery and making fun. The aim of those who do that may be bad or it may be good; we do not know the truth of the matter, but whatever the case it is not permissible to publish such messages; rather we must beware of them and warn others about them.
The number of rak’ahs mentioned in the question refers to the regular Sunnah rak’ahs. For more information on that, please see the answer to question number 1048.
And Allaah knows best.