Tier 2 General Dependent visa( living arrangements )

Dear Friends

i am in UK as Tier 2 General Migration from 01-Jan-2020, i am applying visa for my wife and Daughter as my dependants, during the application process, it require to below question to be answered, when i was making my application i was using my office address. (But at the moment i am living with my friend, does not have any tenancy agreement)
1- Do you know where you will be staying in the UK?
2-Accommodation details?

Now, for my family, do i have to rent a house before i apply visa? or how can i answer this questions,

apart from above question, my child visa need a consent letter from both parents and the guideline says, letter should contain below points, can any one advise me on this, can't we rent a house after visa granted.

CAN ANY ONE PLEASE CLARIFY THIS

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Letter of consent from your parent(s) or legal guardian(s)
A letter of consent that confirms:
the relationship between you and your parent(s)/legal guardian(s)
consent from your parent(s)/legal guardian(s) to the application
consent from your parent(s)/legal guardian(s) to the living arrangements in the United Kingdom and the address where you will be staying
whether one or both of your parent(s)/legal guardian(s) have responsibility for you
Both parents/legal guardians must sign the letter of consent, except where only one parent/legal guardian has sole responsibility for you.
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I've lived in shared houses where a room was rented by family of 2 and sometimes by family of 3.
In your application where live right now is where you live, it doesn't need to much explanation on it's shared or not or who else is living with you.
About the letter, these are the points you need to mention in the letter.