Multifamily real estate presents tremendous opportunities for investors to make money. Rental rates and operating expenses determine the Net Operating Income (NOI), which is total rent collected minus expenses. Savvy investors have the ability to improve both of these variables by identifying value add opportunities. The best value add opportunities arise from relatively small problems or shortcomings that investors can fix in a short amount of time. 
Increase Cash Flow
Cash flow derives primarily from rent. When analyzing a property prior to a purchase, an investor looks for a location where rents lag behind current market rates. This situation creates an immediate opportunity to increase cash flow by raising rents.
Property owners and managers measure the local rental market by using online tools like Zillow, Trulia, or RentBits to study data about current rents. When the market shows that people will pay more for a comparable unit, then landlords can write new leases that reflect these market rates and thereby boost revenue. 
Even when rents match the current market, investors may have viable opportunities to raise rents through upgrades. Wiring units with smart technology presents a quick way to attract higher-paying tenants. Schlage and Wakefield Research reported that 86% of Millennials would pay 20% more for a smart apartment. Among Baby Boomers, 65% would consider paying more. 
On other occasions, upgrades, like nicer kitchen appliances or washers and dryers in an apartment that previously lacked a laundry facility, empower landlords to ask for more rent. Expanding amenities at a property attracts more renters as well who may pay a higher rent. Popular amenities that could be cost-effective additions include barbecue areas, playgrounds, or patios. 
Decrease Operating Expenses
Investors serious about upping their NOI apply bean-counting scrutiny to their expenses. The process starts by identifying problem areas that chronically cost money or are likely to cost more money in the future. For example, placing cheap water heaters in units results in more breakdowns, more labor, and more frequent replacement costs. Choosing higher-quality water heaters could cut costs over time despite a larger upfront cost. Similarly, aging heating and cooling equipment creates frequent service calls. Managers either need to invest more in preventative maintenance or modern, efficient equipment. 
Other expenses could be corrected by replacing outdated office administration and record keeping systems that are driving up labor costs. Improving water use efficiency offers another cost-cutting strategy for landlords who pay water bills. The installation of low flow shower heads produces savings. 
At times, landlords need to shop for new service providers. Not all property management companies are created equal. A good one can cut costs. 
Improve the Occupancy Rate
A constrained supply of housing across most of the nation means that properties should have strong occupancy. However, a poor turnover process robs investors of revenue when units stand empty due to slow repair and leasing processes. An efficient property manager gets maintenance done as soon as a unit empties and engages in effective marketing. A strong online advertising strategy that reaches ideal tenants increases the pool of prospective renters. Of course, applicants must be vetted carefully to avoid the revenue killer of non-paying tenants and evictions. 
The application of strategies that increase the NOI allows investors to make more money. Keeping rents in line with the market and efficient spending can transform a modestly profitable property into a highly profitable one with an increasing overall value.
  https://www.visiolending.com/blog/ideas-for-increasing-noi-at-multifamily-properties
   https://www.powellpropertymgt.com/seattle-area-property-management-blog/ways-reduce-apartment-expenses-operating-costs-washington