Wa `alaykum as-Salamu wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
2- As for your case, you have not reached the level of necessity (darurah), so you have to avoid this mortgage so as to avoid unlawful (haram) financing which has fatal consequences on the whole family affairs.
In his response to your question, Prof. Dr. Monzer Kahf,Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
Dear noble sister, your husband is 100% right. The necessity concept applies to minorities not to the Muslims of Nigeria. Muslims in Nigeria should have established several Islamic banks by now. Not only one.
Besides, thanks to Allah that an Islamic bank is established there and it’s close to you, just in Abuja. You can use the facility from the Islamic bank. There are also other companies that provide Islamic finance companies which you can contact. One of them is Lotus Capital.
Allah Almighty knows best.