Most European home-equity products force one shape onto every borrower: a lifetime mortgage that compounds for thirty years, or a vanilla amortiser that ignores age entirely. Maisonflex is built on a different premise — that the right product depends on where the borrower sits on the life curve, and that the lender's economics should be paid as you go, not stored up as a tail risk. These are the rules that fall out of that premise.
Incumbents make the borrower choose between a residential mortgage and an equity-release plan. We don't. The borrower's age picks the shape: under 55 it's a conventional amortiser; between 55 and 79 it's a partial amortiser that hands off to the reverse-mortgage market at 80; from 80 it's a true lifetime facility with a no-negative-equity guarantee. One product surface, three engines underneath.
Forcing a 60-year-old onto a 25-year amortiser is what locks European wealth into stone. We size the amortisation so the balance lands at ~20% of the projected home value at age 80 — the level at which today's reverse-mortgage market reliably refinances. The borrower pays less per month, keeps more cash in their life, and the handover is engineered in from day one rather than improvised at the end.
Shared-appreciation mortgages have a deserved bad name in the UK because the lender's slice compounded silently for two decades and then surfaced as a six-figure shock at sale. We settle it every year. The borrower elects a share (0–30% of that year's home-price appreciation) in exchange for a coupon discount (0–250 bps). Nothing accrues, nothing compounds, nothing surprises the heirs.
Because appreciation is already paid each year, the no-negative-equity guarantee only needs to cap the compounding loan balance against the home value at exit. That's a cleaner promise than the market convention of pro-rating the cap across balance and appreciation, and it's why our insurance loading only switches on in lifetime mode — the amortising products simply don't carry the tail.
Borrowers can elect a 1, 2 or 3 year IO period at origination. The monthly payment during IO and after IO are shown side by side, with the same coupon throughout — no IO surcharge, no teaser-rate trick. The post-IO payment re-amortises to the same target balance, so the IO years cost cash flow, not life-of-loan economics.
30% LTV at 55, scaling linearly to a 70% cap by the mid-80s. This isn't a blind generosity curve; it reflects that a 55-year-old typically still carries meaningful mortgage debt as a share of home value, while an 85-year-old usually owns outright and has a shorter horizon over which the lender's compounding risk can run away.
The calculator runs in the browser. Nothing is sent anywhere. Numbers are rounded to round-number realism — not promised — and any cap, deficit, or refinance assumption is surfaced on screen rather than hidden in a footnote. The point is to make the trade-offs legible, not to close a sale.
| Dimension | Typical EU incumbent | Maisonflex |
|---|---|---|
| Product shape | One shape per provider — either lifetime or residential. | Three shapes, switched by age, on a single platform. |
| Appreciation share | Accrues silently to maturity; settled at sale. | Settled annually in cash; never compounds. |
| Amortisation target | €0 (residential) or never (lifetime). | 20% of projected home value at age 80, then refi. |
| Insurance loading | Baked into a single headline rate, often opaque. | Only applied in lifetime mode; age-scaled and shown. |
| Interest-only option | Rarely offered, often at a 10–25 bps surcharge. | 0–3 years, no surcharge, both payments displayed. |
| NNEG cap | Pro-rated across balance and appreciation. | Applied to the loan balance only — appreciation is already paid. |
| Quote experience | Adviser-mediated, multi-week, paper-heavy. | Browser-resident calculator with no data egress. |
The result is a product that looks conventional to a 45-year-old, looks like a partial amortiser to a 65-year-old, and looks like a lifetime mortgage to an 82-year-old — but is the same facility, priced on the same coupon, governed by the same rules. That's the design.