The Mathematics of Renovation: Stop Guessing, Start Calculating

One of the biggest challenges in apartment renovation is buying the exact right amount of building materials. Buy too little, and you halt construction while paying for extra delivery. Buy too much, and you waste money on non-refundable items. For a standard 50 sq.m. one-bedroom or compact two-bedroom apartment, precise calculation is key to staying on budget.

1. Calculating Flooring Materials

To calculate laminate, quartz-vinyl, or tiles, you need the exact floor area of each room. However, you cannot just buy 50 sq.m. of flooring for a 50 sq.m. apartment. You must account for waste during cutting. The Rule of Thumb: Add 5% to the total area for straight laying, and 10-15% for diagonal laying. For example, if your living room is 20 sq.m., buy 21 sq.m. of laminate for a standard layout. To avoid manual math errors, Calculate your exact renovation cost for free with Jondeu.

2. Estimating Wall Materials (Plaster, Putty, Paint, Wallpaper)

Wall calculations are based on the perimeter of the room multiplied by the ceiling height, minus the area of doors and windows.

  • Plaster: A 50 sq.m. apartment typically has about 120-140 sq.m. of wall surface. If walls are highly uneven, you might need up to 1.5-2 bags (30kg) of plaster per square meter.
  • Paint: Check the manufacturer's coverage rate (usually 1 liter per 8-10 sq.m.). Always calculate for two coats.
  • Wallpaper: A standard roll is 1.06m wide and 10m long. Divide the room perimeter by 1.06 to find the number of strips, then see how many strips fit in one roll based on your ceiling height.

3. Electrical Cables and Plumbing Pipes

Electrical wiring is notoriously difficult to estimate. A modern 50 sq.m. apartment requires surprisingly long cable runs. On average, expect to use:

  • 150-200 meters of 3x2.5 mm cable for sockets.
  • 100-150 meters of 3x1.5 mm cable for lighting.
For plumbing, measure the linear distance from the risers to each water point (sink, toilet, shower) and add 20% for bends and fittings.

4. The Importance of a Contingency Margin

Even with perfect calculations, materials break, tiles chip, and paint spills. Always keep a 10% financial buffer for material repurchases. If you want a comprehensive, room-by-room breakdown of every screw, bag of cement, and roll of wallpaper needed, Calculate your exact renovation cost for free with Jondeu.

Conclusion

Estimating materials for a 50 sq.m. apartment doesn't have to be a guessing game. By measuring accurately, applying standard waste margins, and using professional calculation tools, you can optimize your purchases and eliminate unnecessary waste.