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add year 0 row and Nebenkosten mitfinanzieren toggle

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Johannes
2026-03-20 02:33:17 +01:00
parent 9d735fb10f
commit 183e69f0b7
4 changed files with 106 additions and 11 deletions
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34
calc.js
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@@ -13,7 +13,16 @@ function run_simulation(p) {
const months = p.years * 12;
// --- mortgage setup ---
const loan = p.home_price * (1 - p.down_pct / 100);
const down_payment = p.home_price * (p.down_pct / 100);
const closing_costs = p.home_price * (p.closing_buy_pct / 100);
// if financed: closing costs rolled into loan, buyer only needs down payment upfront
const loan = p.finance_nebenkosten
? p.home_price * (1 - p.down_pct / 100) + closing_costs
: p.home_price * (1 - p.down_pct / 100);
const upfront_buy = p.finance_nebenkosten
? down_payment
: down_payment + closing_costs;
const r_m = p.interest_rate / 100 / 12;
const n = p.loan_years * 12;
let monthly_payment;
@@ -23,9 +32,6 @@ function run_simulation(p) {
monthly_payment = loan * (r_m * Math.pow(1 + r_m, n)) / (Math.pow(1 + r_m, n) - 1);
}
// upfront costs for buyer
const down_payment = p.home_price * (p.down_pct / 100);
const upfront_buy = down_payment + p.home_price * (p.closing_buy_pct / 100);
const start_capital = p.start_capital || 0;
// --- state ---
@@ -53,6 +59,26 @@ function run_simulation(p) {
let breakeven_month = null;
// --- year 0 snapshot (day of purchase) ---
const selling_costs_0 = home_value * (p.closing_sell_pct / 100);
labels.push('Jahr 0');
buyer_nw_arr.push(Math.round(home_value - selling_costs_0 - balance + buyer_portfolio));
renter_nw_arr.push(Math.round(start_capital));
cum_buy_arr.push(Math.round(upfront_buy));
cum_rent_arr.push(0);
detail_arr.push({
house_value: Math.round(home_value),
mortgage_balance: Math.round(balance),
buyer_portfolio: Math.round(buyer_portfolio),
yr_interest: 0,
yr_principal: 0,
yr_upkeep: 0,
yr_rent: 0,
yr_renters_ins: 0,
kaufnebenkosten: Math.round(closing_costs),
finance_nebenkosten: p.finance_nebenkosten,
});
const invest_r_m = p.invest_return / 100 / 12;
const app_r_m = p.appreciation / 100 / 12;
const rent_inc_m = p.rent_increase / 100 / 12;