Sample IRR for an Owner Occupied House-- 25% down payment
Your new home costs: $150,000
Your downpayment must be: 25.00%
Your equity (downpayment) is: $37,500
Your First Mortgage is: $112,500
Your interest rate is: 6%
Your amortization period is: 20 years
Your imputed rent is: $1,200 per month
Your mortgage cost is: ($9,808.26) per year
Your net imputed rent is: $4,591.74 per year
The annual inflation rate in housing is: 1.50%
You sell your home after five years for:  $    161,592.60
Principal paid on your mortgage is:
Year 1 ($3,058.26)
Year 2 ($3,241.76)
Year 3 ($3,436.26)
Year 4 ($3,642.44)
Year 5 ($3,860.99)
Total ($17,239.71)
Principal remaining after five years $95,260.29
Your cashflow profile is:
Year 0 -37500 1
Year 1 $4,591.74 1.2215
Year 2 $4,591.74 1.492055
Year 3 $4,591.74 1.82254
Year 4 $4,591.74 2.226227
Year 5 $70,924.05 2.719329
Net cash gain  $      51,791.00
Total cash returned  $      89,291.00
Your equity IRR is: 22.1% $0.00 check
One project like this, your cash returned in 5 years is:  $      89,291.00
Leverage implies that with 5% down you get much more cash in five years with five projects than with just one.
The risk of vacancies with five projects is probably lower than with one-- if one tenant moves out, you have a vacancy rate
of 20% in your 5 home portfolio. If you have only one project, your vacancy rate skyrockets to 100%.
However, the risk of a economy wide meltdown, and a default to your bank is probably higher with the 5 unit model.
Project IRR is 
Year 0 -150000
Year 1 $14,400.00
Year 2 $14,400.00
Year 3 $14,400.00
Year 4 $14,400.00
Year 5  $    175,992.60
Net cash gain  $      83,592.60
Total cash returned  $    233,592.60
Your project IRR is: 10.8%
The IRR on the project is made up of the 'weighted average' IRR on your equity (22%) plus the IRR
on your debt (6%).