Small multifamily owners are going to have to reduce prices quite a bit if they need to sell. 

@Alan Miller Here's a list of things to consider.A single family has a larger market than a double when it comes time to sell.You have more single family properties to choose from.A typical tenant in a single seems to stay longer than in a multi reducing turnover time and costs.A double or small multi will bring in more cashflow.A double is more likely to have neighbor conflicts if it is an over/underAlso consider the condition at the purchase.

Since they want to rent a majority of the property is there a way I can reduce my property taxes?

Weak numbers in the first two years of that five year period reduced their appraisal of the property and required we do a cash-in refi. 

If you included  the cost of a new roof in your net operating statement it would serve to reduce operating income and therefore reduce cap rate and the value of the building all during one period, and the next period that did not have a new roof expense would then have a sharply higher NOI and therefore value of the building.  

We have asked him to reduce the rent if he wants to live at his property or give us due notice that he plans to use his office.

Hey SoBeREI, If you are interested and have CASH to invest, I have a deal right now on a multi-family lot, 3 duplexes, worth 750K to 950K, under renovation, 6 total units, vacant, rents go for $1100 per month in Ceres, California, investor asking $599,000 recently reduced to sell faster.

This will reduce some of your risk by hopefully scoring trustworthy team members from the start. 

You can use a studs or wood nailer strip to reduce the amount of sqft you'lll be losing on the block.

Our local Natural Gas Utility offers this:"Reduced-cost weatherizationAdditionally, Energy Trust of Oregon now offers Savings Within Reach to NW Natural customers with household incomes up to 120 percent of the state median income (SMI).