For those following along, here's some numbers on how this might play out:

**Scenario:** Dual-income couple purchases 'forever home' for $500,000 with a $400k / 30y mortgage @ 4% fixed. Each partner contributed 10% of the downpayment ($50k each) Wishing to rid themselves of the mortgage as quickly as possible they over-pay an extra $2,000/mo - saving nothing else. Under that plan they would pay off the year in 10 years 6 months.

BUT - their marriage falls apart after 7 years. The home appreciates at 3%/year

**The math:**

Mortgage = $1909.

Accelerated payments = $2,000

Taxes (at 1.5%) = $650

**Total monthly payment: $4,535**

At the 7 year mark they've paid off $250k (63%) of the original $400k mortgage.

The house is now worth $615k (due to appreciation)

**Splitting the asset**

Total home equity = $465k ($615k home value - $150k remaining on the mortgage)

Partner A does not want to sell the home, so s/he owes Partner B $232.5k

The lender offers a HELOC of 4.5% APR with a 15y Amortization. HELOC payment = $1,780/mo

Partner A would have monthly payments of $3,689 without bonus mortgage payments. It will now take Partner A an additional 8years, 5 months to pay off the mortgage.

Unfortunately, without Partner B's income s/he cannot afford the $4,315 monthly payments (Minimum Mortgage + HELOC + Taxes).

**However...**

The bank sees this and restricts the HELOC to $100k (the maximum amount they consider Partner A able to pay based on assets and salary)

Newly divorced couple winds up with unorthodox living arrangement.