Even if you do not have permanent residence, you may be able to borrow a housing loan, but the fact is very difficult.
Bank basic requirement
If you do not have permanent residence, you have to apply the following contents.
1.Employment form is only regular employees "seishain." ※not contract employee "keiyaku shain" and temporay " haken shain, of course not self employed "jiei"
2. You have been worked for over 3 years in the same company.
3. You have been lived in the same house for over 3 years.
4. You have been in Japan for over 5 years.
5. Also Japanese ability is more than 70% ※included Kanji,Katakana,Hiragana
No.1-No.4 is very important factor.
If you do not apply to all contents of No.1-No.4, you can not make a bank examination.
If you do not apply above contents ,you will wait untill you apply these contents (at least No.1-No.4) or I think you may start your house planning after getting permanent residence.