Simple! When you measure the space in which you'd like to put your shelf, you'll need to take into account any baseboards/skirting boards, where any light switches, fixtures or electrical sockets are located, as well as the location of any other architectural or decorative details. You'll want to make sure you have plenty of space so that your shelf (and its opening doors or drawers) doesn't bang, obstruct or cause any clearance issues.
Next you'll use your measurements to design your shelf in the configurator. Be sure again that you have enough clearance for all doors and drawers to open freely, and not bump anything. Tylko furniture is delivered in flat pack boxes, and you'll assemble your unit while it's lying down and then stand it up in place. Make sure you allow enough room on the floor to assemble your full shelf. Finally, you'll need to leave enough ceiling clearance to lift your Tylko into place. This handy chart shows the maximum shelf height possible for each ceiling height (in cm).