Is it permissible to restrict oneself to performing only some of the rak'ahs of the "12 rak'ahs in a day and night" prayer, the virtue of which—building a house in Paradise for whoever performs it completely—has been reported?

Among Allah's favors upon His servants is that He rewards those who pray twelve supererogatory rak'ahs daily by building a house for them in Paradise, as stated in the Hadith (definition): "There is no Muslim servant who prays to Allah twelve supererogatory rak'ahs every day, other than the obligatory prayers, except that Allah will build for him a house in Paradise." These rak'ahs include the regular Sunnah (definition) prayer of 'Isha', and the Hadith detailed them as follows: four rak'ahs before Dhuhr, two rak'ahs after it, two rak'ahs after Maghrib, two rak'ahs after 'Isha', and two rak'ahs before Fajr. The mentioned reward is only attained by performing twelve rak'ahs with perseverance.