There are specific rules for 1031 exchanges including:The replacement property must be identified within 45 days of transferring the relinquished property.The replacement property must be received within 180 days after the transfer of the relinquished property or the due date of the taxpayer's tax return, whichever is earlier.Special rules apply for exchanges between related parties (defined in § 267(b) or 707(b)(1)).Real property located in the United States and real property located outside the United States are not considered property of like kind.Cost Segregation StudiesA Cost Segregation study is an IRS approved federal income tax tool that increases near term cash flow by utilizing shorter recovery periods for depreciation to accelerate return on investment.

This is for mid-range quality and minimal assembly items- what you save in purchase price you will lose in replacement and assembly costs!

I haven't built much equity in it in just one year but I considering replacing my current mortgage with a first lien heloc.

Have you ever purchased a property and replaced all the systems like a total gut job, new electrical plumbing ect?   

That doesn't give them what they need.If it needs a stamp by a licensed Architect or Engineer, that cost would be additional.

Is the house a small two story with 800 sq ft of composite shingle roofing that needs to be replaced, or a large one story with tile roofing?.  

It demanded to replace full flooring, scrape walls and repaint costing entire year worth of rent from that unit.Question: are there technical solutions inexpensive to remove cat urine instead of replacing all wood , carpet and walls?

They can also be another item that will need maintenance / replacements if they break down. 

I put regular laminate countertops etc in them as they will be cheaper to replace, but the homes are nice section 8 homes.

I would say including architect, engineering and permitting costs, you'd be at about $250,000.