I agree with @Aaron Zimmerman—setting up your chart of accounts to align with Schedule E/1040 or 1065, depending on your type of entity, will again take some of the heavy lifting come tax time.

What I am saying is the tax bill for you could be wildly different depending on how long your partner has owned this property and how much depreciation they have taken.  

It really depends on your bigger picture and also what you are hoping to accomplish in the future.

Since I'm not a lawyer, there might be a specific reason, depending on your situation, why that might be useful.On the other hand, I've seen crazy large structures for small portfolios, and there are many attorneys willing to charge you for the help of setting them up. 

@Jonathan LudizacaIt really depends on the market.

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.

I personally think it really depends on how much value will it add to the property and if the town will allow it. 

It can get pretty expensive what would anyone suggest or should I write the lease so that the next tenant depending on time of year should I do not include a specific utility and adjust my rent because of it ? 

Lenders typically require at least 15-20% down for multifamily properties, depending on the specifics of the deal.

As a CPA, it's very client dependent.