Multifamily Strategy — Where Residential Ends and Commercial Begins
What commercial multifamily actually is, why it's a different game, where investors go wrong, and how to read a multifamily deal through the CDeal analyzer.
There's a line in real estate investing that most new investors don't realize exists. On one side is residential — houses, duplexes, fourplexes, the stuff you can buy with a conventional loan and the knowledge you pick up on BiggerPockets. On the other side is commercial — apartment buildings, office parks, retail centers. Different financing. Different valuation. Different rulebook entirely.
That line is drawn at 5 units. A fourplex is residential. A fiveplex is commercial. Same bricks, same tenants, completely different investment world.
This guide is about commercial multifamily — 5+ unit apartment buildings. If you're looking at a duplex, triplex, or fourplex, use the Rentals guide (or House Hacking module for 2-4 units where you'll live in one). The CDeal Multifamily analyzer and everything in this guide is built for the 5+ unit commercial tier.
What commercial multifamily actually is.
A 5+ unit apartment building is a small business that happens to be a real estate asset. You own the building, you have multiple tenants paying rent, and you operate it — either directly or through a property management company.
The strategy is straightforward: buy a stabilized or under-performing apartment building, operate it well, increase the NOI (Net Operating Income) over time, and either hold it for cash flow or sell it for forced-appreciation gains.
Typical deal sizes:
Small commercial (5-20 units).
Often owned by individual investors or small partnerships. Financing is easier, prices range from $500K to $5M. Entry point for most serious commercial investors.
Mid-market commercial (20-100 units).
Owned by experienced investors, partnerships, or small private equity. Prices $5M-$30M. Requires significant capital and a real team.
Institutional commercial (100+ units).
Owned by private equity, REITs, or institutional funds. Prices $30M+. Not a DIY investor space.
This guide focuses on the small commercial tier (5-50 units) — the range where an individual investor or small partnership can still compete without a full institutional team.
Why commercial multifamily is a different game.
Three things change the moment you cross the 5-unit line.
First, financing changes.
Residential loans (conventional, FHA) are gone. You're now in commercial loan territory. Lenders qualify the property, not you. They want to see the property's NOI cover the debt service with margin (DSCR 1.25+ typically). They don't care about your W-2 the way a Fannie Mae lender does. Loan terms are shorter (5-10 years typical), amortization is often 25-30 years, rates are usually 0.5-1.5% higher than conventional residential. The tradeoff: you can scale past Fannie Mae's 10-property cap. There's no cap on commercial loans.
Second, valuation changes.
Residential properties are valued on comparable sales — what did similar houses sell for recently? Commercial multifamily is valued on NOI ÷ Cap Rate. This is a huge shift. It means you can increase a property's value by increasing its NOI (raising rent, cutting expenses, filling vacancies), independent of what the market is doing. This is called forced appreciation and it's the single biggest wealth-building mechanic in commercial real estate. Learn more →
Third, operations matter more.
A single-family rental can tolerate a lazy landlord for a while. A 20-unit apartment building cannot. You have 20 tenants, 20 leases, 20 maintenance streams, and 20 revenue relationships to manage. Without systems, the building collapses operationally within a year. Most new multifamily investors either hire a property management company (6-10% of gross rent) or they learn operational discipline the hard way.
Financing commercial multifamily — the capital stack.
Commercial multifamily financing is its own world. Here's the menu.
- Agency loans (Fannie Mae / Freddie Mac). The gold standard for stabilized apartment buildings. 10-year fixed rates, 30-year amortization, non-recourse (the building is the collateral, not your personal assets). Competitive rates. Minimum loan size usually $1M-$3M depending on the lender. Requires 25-30% down plus significant reserves. If you can qualify for agency financing, take it.
- CMBS loans (Commercial Mortgage-Backed Securities). 5-10 year fixed rates, similar terms to agency but more flexibility on property condition and borrower requirements. Rates slightly higher. Sold into the securitization market, which makes them inflexible on modifications if something goes wrong.
- Bank loans (portfolio lenders). Local and regional banks that hold multifamily loans on their own books. Usually 5-7 year terms with 20-25 year amortization, often with a balloon at maturity. More flexible than agency/CMBS but shorter terms create refinance risk. Often the only option on smaller buildings (under $1M).
- Bridge loans. Short-term (1-3 year) loans for value-add deals where you're buying a distressed or under-performing property, repositioning it, and refinancing into permanent debt. Higher rates (8-12%), origination fees, interest-only payments. Used when the property can't qualify for permanent financing today but will after improvements.
- Seller financing. The seller acts as the bank. More common in commercial than residential because sellers often have significant equity and want to defer taxes on the sale. Terms are negotiated — below-market rates, flexible down payments, creative structures. Rare but powerful when it shows up.
- Syndication equity. Instead of (or in addition to) debt, you raise equity from other investors. You're the sponsor managing the deal, they're limited partners providing capital. Common structure: 20-30% of the purchase in equity, 70-80% in debt. Requires SEC compliance and is a full separate topic — but it's how most large commercial deals actually get done.
For most individual investors starting out, the stack looks like: agency or bank loan (70-75%) + your own equity (25-30%) + cash reserves (6 months of operating expenses minimum).
The honest pros.
- Forced appreciation through NOI. The single biggest advantage. Increase the rent by $50/unit/month across 20 units, and at a 6% cap rate, you just added $200,000 in property value. No market appreciation required. Learn more →
- Scale without personal qualification limits. Commercial loans qualify the property. You can own $20M in apartment buildings without the personal income or the 10-property cap that chokes residential investors.
- Professional-grade cash flow. A stabilized 20-unit building typically generates $15K-$40K/month in gross rent, which after expenses and debt service can deliver $3K-$10K/month in net cash flow. Real income, not hypothetical.
- Operational efficiency through scale. One property manager handles 20 units at roughly the same cost as 4 separate single-family rentals. Economies of scale are real in multifamily. The more units, the better the per-unit economics.
- Tax advantages compound. Cost segregation studies on commercial buildings can accelerate depreciation dramatically, creating significant paper losses that offset rental income. Talk to a CPA who specializes in commercial real estate — the tax strategy here is more sophisticated and more rewarding than residential.
The cons — where commercial multifamily goes wrong.
- Capital requirements are real. A $2M apartment building requires $500K-$600K down plus reserves. This is not a "start with $30K" strategy. Without substantial capital or a syndication structure, you can't play in this tier.
- Operating complexity is underestimated. Twenty tenants means twenty relationships, twenty maintenance streams, twenty turnover cycles, twenty potential eviction headaches. Without a property management company or serious operational skills, the building spirals fast.
- Cap rate expansion risk. You bought the property at a 6% cap rate. Two years later, interest rates rose and the market is now pricing similar properties at 7%. Same NOI, but your property just lost 14% of its value through cap rate expansion alone. 2022-2024 saw this happen across the entire commercial real estate market.
- Shorter loan terms create refinance risk. Most commercial loans are 5-10 year terms. When the balloon hits, you refinance — but at whatever rates are available then. If rates are dramatically higher or the property's NOI has slipped, the refinance can fail or require major capital injections.
- Tenant quality volatility. Apartment buildings in slower markets attract lower-income tenants, which means higher delinquency, more turnover, more property damage, and more legal costs. High-yield cap rates often come with tenant bases that make those yields very hard to actually capture.
- Operational surprises scale with unit count. A roof replacement on a fourplex is $15K. On a 20-unit building it's $60K. A boiler on a 40-unit building is $40K. CapEx on commercial buildings is a different order of magnitude than residential, and it hits in big chunks.
- Harder to exit. Selling a commercial multifamily building takes 60-180 days, requires institutional-quality financials, and is heavily dependent on market cap rates at exit. You can't just drop a sign in the yard.
Who commercial multifamily is for — and who it isn't.
Multifamily is for you if:
You have $200K+ in liquid capital (or access to syndication partners), you've already built operational muscle on smaller properties, you're comfortable with longer hold periods (5-10 years minimum), and you want to build real wealth at commercial scale.
Multifamily is not for you if:
You have less than $100K saved (you can't survive the capital demands), you haven't owned rentals before (the operational jump is brutal), you need liquidity (commercial is slow to sell), or you're looking for passive income (a multifamily building requires active or semi-active management even with a property manager).
The best path into commercial multifamily is a progression: start with a house hack, scale to a few rentals, then step up to a small 5-10 unit building. Skipping the progression and starting with commercial is expensive to learn on.
How CDeal's Multifamily Analyzer reads each stage.
Stage 1 — Acquisition + Loan Structure.
You input the purchase price, down payment, commercial loan terms (rate, amortization period, term length), property taxes, and insurance. CDeal calculates your cash-to-close and monthly debt service. Watch the cash-to-close — commercial deals can require $300K-$800K of your own capital, and closing with thin reserves is dangerous.
Stage 2 — Unit Mix + Gross Rent.
You enter the unit count by type (1BR, 2BR, 3BR) and the rent per unit. CDeal calculates gross potential rent and effective gross income (after vacancy allowance). Watch the vacancy assumption — commercial markets typically run 5-10% vacancy, and assuming lower is optimistic.
Stage 3 — Operating Expenses + NOI.
You enter operating expenses (taxes, insurance, utilities, repairs, management, reserves). CDeal calculates NOI. Watch the OpEx ratio — commercial multifamily runs leaner than residential due to scale, typically 35-45% of gross rent, but anything below 30% is underbudgeted. Learn more →
Stage 4 — Cash Flow + DSCR.
CDeal calculates monthly cash flow after debt service and the Debt Service Coverage Ratio. For commercial loans, DSCR is everything. Below 1.25 most lenders walk. 1.30-1.50 is the comfortable zone. Above 1.50 means the deal has real margin. Learn more →
Stage 5 — Cap Rate + Property Value.
CDeal calculates the cap rate based on your purchase price and NOI, and shows the projected property value at exit based on stabilized NOI and assumed exit cap rate. Watch the spread between entry cap and exit cap — you want to buy at higher cap (lower price per NOI) and exit at lower cap (higher price per NOI) when NOI has grown. Learn more →
Stress Test.
CDeal runs the deal against commercial-specific scenarios — cap rate expansion (exit at 100bp higher than entry), vacancy spike (10% vacancy), major CapEx event, and rate shock on refinance. Watch cap rate expansion especially — it's the biggest uncontrollable risk in commercial.
Verdict.
The final card names the weakest number in the deal and tells you where to push on price, unit mix, or financing.
Let's walk through a real 12-unit apartment building deal.
The deal:
- Purchase price: $1,450,000
- Down payment: 30% = $435,000
- Loan: $1,015,000 at 6.75%, 25-year amortization, 10-year term
- Unit mix: 8x 1BR at $1,150/month + 4x 2BR at $1,450/month
- Vacancy assumption: 7%
- Operating expenses: 42% of gross rent
- Market cap rate for this property type/area: 7.0%
The question: Does this deal work? What does the cap rate tell us? Would a commercial lender fund it?
Step 1 — Gross Potential Rent.
8 × $1,150 = $9,200/month
4 × $1,450 = $5,800/month
GPR: $15,000/month = $180,000/year
Step 2 — Effective Gross Income (after vacancy).
$180,000 × (1 − 0.07) = $167,400/year
Step 3 — Operating Expenses.
42% of $180,000 GPR = $75,600/year (use GPR for OpEx, not EGI)
Step 4 — NOI.
$167,400 − $75,600 = $91,800/year
Step 5 — Annual Debt Service.
Monthly P&I on $1,015,000 at 6.75%, 25-yr amortization: ~$7,015/month
Annual: ~$84,180/year
Step 6 — Cash Flow.
$91,800 NOI − $84,180 debt service = $7,620/year ($635/month)
Step 7 — DSCR.
DSCR = NOI ÷ Debt Service = $91,800 ÷ $84,180 = 1.09
Step 8 — Cap Rate.
Cap Rate = NOI ÷ Purchase Price = $91,800 ÷ $1,450,000 = 6.33%
Step 9 — Cash-on-Cash Return.
$7,620 cash flow ÷ $435,000 invested = 1.75%
Verdict: This deal doesn't work as priced.
- DSCR of 1.09 is below lender minimums. Most commercial lenders require 1.25+. The bank will either deny the loan or demand more equity.
- Cap rate of 6.33% is below the market rate of 7.0%, meaning you're paying a premium for this property. Either the seller's pricing is optimistic or the broker is fishing for a less-sophisticated buyer.
- Cash-on-cash of 1.75% is weak. You'd earn more in a high-yield savings account, with no risk and full liquidity.
The fix:
Negotiate the purchase price down to around $1,310,000 (7.0% cap on $91,800 NOI). At that price, your loan drops to $917,000, debt service falls to $6,345/month ($76,140/year), DSCR jumps to 1.21 (still thin but much closer to workable), and cash-on-cash improves meaningfully. Better: find a deal where NOI can be grown through operational improvements — that's where forced appreciation pays off.
The commercial lesson:
Unlike residential where you're negotiating off comps, in commercial you're negotiating off cap rate. If you know the market cap rate and the property's NOI, you know what the property is worth. Everything above that is the seller's hope.
Run this exact deal in the CDeal Multifamily Analyzer and all seven stages break down with this math.
- Buying at a cap rate below market. The most common expensive mistake in commercial. You got excited about the property, the broker's pitch was compelling, and you paid a 5.5% cap in a 7% market. You're now underwater on day one.
- Assuming residential operating expense ratios apply. Commercial multifamily has its own OpEx profile — typically leaner than residential due to scale, but with bigger CapEx events. Don't apply single-family math to a 20-unit building.
- Ignoring cap rate expansion risk on exit. You bought at a 6% cap and assumed you'd sell at a 6% cap five years later. Rates rose, cap rates expanded to 7%, and your exit value just dropped 14%. Always stress-test exit at +100bp cap rate expansion.
- Underestimating operational complexity. A 15-unit building is not 15x a single-family rental in workload — it's often 5-10x, thanks to scale economies and systems. But if you don't have the systems, it's 20x. Hire a property manager or commit to becoming one yourself.
- Thin cash reserves. A roof replacement, a boiler failure, or 90 days of elevated vacancy can eat $40K-$80K on a 20-unit building. Closing with less than 6 months of operating expenses in reserves is how commercial owners lose properties.
- Skipping the operating history. A seller can show you any trailing-12-month financial they want. Always ask for 36 months of rent rolls, bank statements, and tax returns. Verify the income. Verify the expenses. Every year of missing data is a year the seller doesn't want you to see.
- No exit plan. You bought the building. Great. Now what — are you holding for cash flow forever, refinancing at year 5, or selling at year 7? Commercial deals need a defined exit before you buy. Otherwise you're just hoping.
Multifamily Strategy Quiz — 4 Questions
Get all 4 correct to mark this guide complete.
Commercial multifamily is the most powerful scaling strategy in real estate — and the strategy with the biggest gap between what works on paper and what works in practice. The math is clean. The execution is brutal. The difference between multifamily investors who build real wealth and multifamily investors who lose millions comes down to disciplined underwriting, honest operations, and respect for the commercial rulebook.
Cap rate is the number that tells you what the market thinks. NOI is the number you actually control. DSCR is the number the bank cares about. Operational discipline is the skill that ties them all together.
Run every multifamily deal through the CDeal analyzer before you write an offer. Stress test the exit. Stress test cap rate expansion. Verify the operating history before you close. And if the deal doesn't beat the market cap rate going in, walk away — there will be another deal next month, and the one that requires you to compromise on pricing is almost always the one that burns you.
Multifamily is a business, not a passive investment. Respect the business and it builds generational wealth. Treat it like bigger residential and it eats you alive.