Praise be to Allaah.
We do not know of this hadeeth to which you refer. The one who it is proven will carry things on his back on the Day of Resurrection is the one who took things unlawfully from others in this world, whether by force or by stealth, or stealing booty from the battlefield before the spoils of war were distributed.
It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: The Prophet (peace and blessings of Allaah be upon him) stood before us and spoke about war booty and how serious the matter is. He said,
“I should not like to see anyone amongst you on the Day of Resurrection, carrying on his neck a sheep that will be bleating, or carrying on his neck a horse that will be neighing, saying: ‘O Messenger of Allaah! Help me!’ and I will reply, ‘I cannot do anything for you, for I have conveyed Allaah's Message to you.’ Nor should I like to see a man carrying on his neck, a camel that will be grunting, saying: ‘O Messenger of Allaah! Help me!’ and I will reply, ‘I cannot do anything for you, for I have conveyed Allaah's Message to you.’ Or one carrying on his neck gold and silver, saying: ‘O Messenger of Allaah! Help me!’ and I will reply, ‘I cannot do anything for you, for I have conveyed Allaah's Message to you.’ or one carrying clothes that will be fluttering, saying: ‘O Messenger of Allaah! Help me!’ and I will reply, ‘I cannot do anything for you, for I have conveyed Allaah's Message to you.’”
Narrated by al-Bukhaari, 2908; Muslim, 1831
With regard to a Muslim building a house that is bigger than he and his family need, Ibn Hazm said:
(The scholars) are agreed that it is obligatory for a man to build that which will shelter him and his family from prying eyes and from cold, heat and rain, or to buy a house or dwelling that will cover him in the manner mentioned. And they agreed that it is permissible to seek to earn more money and build a more spacious house so long as that is done by halaal means and he fulfils all his duties towards Allaah, but they differed as to whether that is makrooh or not.”
Maraatib al-Ijmaa’, p. 155
What the Muslim should do is not to go to excess in matters of this world, and to limit himself to what he needs, based on the general meaning of the verses which forbid extravagance, such as the verse in which Allaah says (interpretation of the meaning):
“And those who, when they spend, are neither extravagant nor niggardly, but hold a medium (way) between those (extremes)”
Al-Tirmidhi (4283) narrated from Khabbaab (may Allaah be pleased with him) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “A person will be rewarded for all his spending except what he spends on building.” Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi. Also narrated by al-Bukhaari (5672) from Khabbaab (may Allaah be pleased with him). Ibn Hajar said: This is understood as referring to what exceeds one’s requirements.
This is also indicated by the way the Prophet (peace and blessings of Allaah be upon him) was: he rose above preoccupation with this world, and warned his ummah against indulging in worldly pleasures, as he said in the hadeeth: “By Allaah, I do not fear poverty for you but I fear prosperity in this world as those who came before you became prosperous, and you start to compete with one another in worldly gains, as they did, then you will be destroyed as they were.”
Narrated by al-Bukhaari, 3158; Muslim, 2961.
There is no zakaah due on the houses that a Muslim builds for his family or children, even if their value rises. And houses that he builds to rent them out are not subject to zakaah themselves, rather zakaah is due on the rent if it reaches the nisaab and one whole hijri year has passed. Houses that he builds in order to sell them are subject to zakaah, because they are a kind of trade goods, so after one year has passed he should calculate their value and pay zakaah on them, one-quarter of one-tenth of the total value.
For more details on this issue and the evidence, see the answer to question no. 10823.
And Allaah knows best.