Add a new Mortgage.fs module (or extend the existing mortgage-related calculations) to support three specialist mortgage product structures not currently modelled:
1. Offset mortgages
The interest-bearing balance is reduced by the balances of linked savings or current accounts held with the same lender. The borrower pays interest only on the net balance (mortgage − linked savings), potentially reducing the term or the monthly payment.
2. Equity release / lifetime mortgages
No monthly repayments; interest rolls up (compounds) on the outstanding balance and is settled on property sale or death. Key calculations: projected balance at a given future date; impact of voluntary partial repayments; no-negative-equity guarantee modelling.
3. Shared ownership
The borrower owns a share (e.g. 25%–75%) of the property and pays rent on the remainder. Calculations needed:
- Blended monthly outgoing (mortgage payment + rent).
- Staircasing: cost of buying additional tranches, including updated mortgage and reduced rent.
- Total cost of ownership vs. outright purchase over a given horizon.
Add a new
Mortgage.fsmodule (or extend the existing mortgage-related calculations) to support three specialist mortgage product structures not currently modelled:1. Offset mortgages
The interest-bearing balance is reduced by the balances of linked savings or current accounts held with the same lender. The borrower pays interest only on the net balance (mortgage − linked savings), potentially reducing the term or the monthly payment.
2. Equity release / lifetime mortgages
No monthly repayments; interest rolls up (compounds) on the outstanding balance and is settled on property sale or death. Key calculations: projected balance at a given future date; impact of voluntary partial repayments; no-negative-equity guarantee modelling.
3. Shared ownership
The borrower owns a share (e.g. 25%–75%) of the property and pays rent on the remainder. Calculations needed: