Answered by: Alimah Sofia Mirza
I have some assets and I recently bought a house as well in the UK through a conventional mortgage. It is my understanding that the Zakat is due to be paid net of obligations. When I calculate the zakat next time around do I need to factor in the loan/mortgage that I have on the house (as the house is not considered for the purpose of Zakat computation)?
Many thanks for your guidance. Jazakallahu
In the name of Allah, the Most Gracious, the Most Merciful
The loan/debts a person has which is connected with the rights of other people excuses one from paying Zakat, the loans which have to pay should be deducted from the total wealth and anything which is extra equals to the Nisab of Zakat one will have to pay Zakat for it. If after deducting the loan amount the excess wealth does not equal to the Nisab it will not be Wajib to give Zakat. Furthermore, if a person is paying off the loan in installments he will reduce this amount from his wealth only not the entire amount of the loan at one time and will determine if the excess wealth equals to Nisab he will have to give Zakat. 
In response to your question you will not include the loan/mortgage you have to pay off for the house when calculating Zakat but will subtract the loan and calculate Zakat for the rest of your assets.
Only Allah knows best
Written by Alimah Sofia Mirza
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Hidayah, Al Misbaah, Vol 1, Pg. 186.
 Fatawa Darul Ulum Zakariyyah, Vol 3, Pg. 129-131.