Purchasing a house through taking a loan on interest

Q: We live in a country, where it is impossible to buy a house on a full amount, it is more expensive than Europe. My husband is religious and wonts take a mortgage. We have been married for 2 decades and wasted lots on rental property, and the headaches that come with it. Buying ones own house is a basic necessity and advised by scholars, elders, alike if possible.

1. Is buying a house in installments permissible in Islam? From a real estate developer?

2. Can one use an installment plan which is jaiz, from a bank such as Al Rajhi bank?

Waseelah

Q: Dua me waseelah de kar mangna kaise he? Jaaiz ya najaaiz? Khas tor par Nabi Paak (sallallahu alaihi wasallam) ka waseelah dena. Mazeed ye keh Sahaabah kiram (radhiyallahu anhu) or Ummahat ul Muminin ka waseelah dena kaisa he?