Documenting Property Performance

[Cassandra Brown]

My wife and I recently purchased our first property, a duplex we are house-hacking.  I want to compile a file of information, either digital or physical, that could potentially be used as a piece of documentation showing past successful investments to a bank or lender in the future. I thought I would track profit and costs, repairs and updates we have completed, some photos, details of purchase and rent history etc.  Are there any tools or templates for this sort of document? What have you all used for this sort of thing? What information is good to include and what is unnecessary?

Thanks for any help or input you can provide!