What is house flipping and how to calculate if it's profitable
House flipping means buying a property below its market value, renovating or improving it, and selling it at a higher price for a profit. It is an active strategy and it can pay well, but only after a rigorous analysis of every cost before you buy.
- Net profit = sale price minus ALL costs, including taxes
- Renovation overruns are the most common risk: always add a 10–15% contingency
- Capital gains tax must be in the calculation from day one
- A minimum gross margin of 20–25% on total investment is recommended to absorb the risks
- Study recent comparable sales in the area before estimating your target sale price
- Time is also cost: every month the deal drags on reduces the return
The house flipping process: three phases
Phase 1 — Buy: find an undervalued property (poor condition, inherited, urgent seller, or transitioning neighborhood) at a price significantly below its post-renovation market value. Phase 2 — Renovate: execute the improvements needed for the property to reach its target value. Phase 3 — Sell: bring the renovated property to market at the target price. Your profit is the difference between the sale price and the total of all costs invested.
Every cost you must include in the calculation
Most failed flips fail because costs were underestimated. Key costs: purchase price, transfer taxes or VAT (depending on whether it's a resale or new property), notary and registry fees for both purchase and sale, total renovation cost (materials, labor, plus a 10–15% contingency buffer), financing costs if using a mortgage or bridging loan, real estate agent commission if selling through an agent, and capital gains tax on the profit (typically 19–26% depending on the amount and holding period). Ignoring any of these can turn an estimated profit into a real loss.
Worked example
Purchase price: €120,000. Taxes and closing costs: €12,000. Full renovation: €25,000. Total invested: €157,000. Sale price: €185,000. Gross profit: €185,000 − €157,000 = €28,000. From that, deduct capital gains tax (approximately 19–21% on €28,000 ≈ €5,300–€5,900) and any agent commission. Net profit: approximately €21,000–€22,000, roughly a 13–14% return on total capital invested.
Risks that can eliminate your profit
Construction delays are common: each extra month adds financing costs and delays the sale. Renovation overruns are nearly inevitable without a detailed project and contingency margin. Market changes can make your target sale price unachievable by the time the property is ready. Tax costs, particularly capital gains, often surprise first-time flippers who didn't include them in the original calculation. The general rule: estimated gross margin should be at least 20–25% of total investment for the deal to make sense given all the risks.
The BRRRR strategy: beyond the classic flip
Some investors do not sell after renovating. They rent the property and then refinance. This is known internationally as BRRRR: Buy, Rehab, Rent, Refinance, Repeat. The idea is to recover part of the invested capital through a mortgage refinancing based on the new post-renovation appraised value — without selling — and use that released capital as a down payment for the next purchase. It's more complex than a classic flip as it combines rental management with mortgage debt management, but it can allow portfolio expansion with less initial capital.
Frequently asked questions
What is house flipping?
Buying a property below market value, renovating it and selling it for a profit in a short period.
What costs should I include?
Purchase taxes and fees, renovation, financing, holding costs, selling costs and taxes on the gain.
What margin should a flip have?
Enough to absorb overruns and delays. Many investors aim for a net margin of at least 15–20% on total cost.
What are the main risks?
Renovation overruns, delays, a falling market and overestimating the sale price.