[PersonalFinance] Develop a tool for first-time home buyers to evaluate affordability

34M / 31F, no kids yet but planning in the next few years. Combined income is about $240k/year. We currently have about $90k in retirement accounts and additional savings that we’ve been building toward a house. This would be our first home purchase. Right now we rent a \~1500 sq ft place that we really like. It’s close to my work, my wife works from home, and it’s in a lively downtown/midtown area with lots to do. Our rent is about $2,200/month and overall our living situation is pretty comfortable. The thing is, we’re thinking about the next stage of life. We’d like a quieter environment and a place that would work better for raising kids in the next few years, possibly in a nearby university town that we really like. We recently found a house we’re considering for about $645,000. The house itself is smaller (around 1,000 sq ft) but it has a nice backyard and is right next to a hiking trail, which we love. The financial jump is what’s giving us pause. Our estimated all-in monthly housing cost (mortgage + interest + property tax + PMI) would be roughly $4,500/month, before utilities and maintenance. That’s basically double what we pay in rent today. We’re considering putting about 13% down instead of 20%. The main reason is that we’d like to keep around $40k in savings for closing costs, emergency fund, and general cushion instead of draining our liquidity completely. If we did a full 20% down payment we’d essentially wipe out most of our liquid savings, which feels risky. So the tradeoff looks something like this: Current situation • $2,200/month rent • Larger space (1500 sq ft) • Walkable, lively neighborhood • Very comfortable financially Potential home purchase • \~$4,500/month housing cost • Smaller house (\~1000 sq ft) but with yard • Quiet town environment • Better long-term for starting a family We can technically afford the payment based on income, but the doubling of housing cost and the idea of draining savings is what’s making us hesitate. For those who’ve gone through something similar: • Does this seem financially reasonable given our income? • Is putting 13% down to preserve cash a bad idea? • Are we underestimating the jump in total homeownership costs? Any insight would be appreciated. It feels like one of those decisions where I might kick myself later for either buying or not buying.