Six apartments, six different beds. One 135 inherited from grandmother's flat, two 150s, a 160 because it was on offer, and two rooms with 90 cm beds that are actually 105. Every purchase made sense on its own. Together they cost money every month, and the extra never shows up on an invoice: it shows up in the cupboard, at the laundry and in your cleaning team's time. This is the sum for what it costs not to standardise, and how to get out of it without throwing anything away.
What multiplies is not the linen in use, it is the reserve
Here is where intuition goes wrong. If you have six beds, you need six sets on them, whatever size they are. Linen in circulation does not change because sizes differ: each bed carries its own.
What changes is the reserve. A spare sheet only fits beds of its own size. With a single double-bed size, one set in the cupboard covers an incident in any apartment. With three sizes, that same set covers a third of your portfolio, and to sleep as soundly you need a reserve for each size.
The rule, in one line:
reserve pieces = the reserve you want available × the number of different sizes
With six apartments and one double size, two spare sets cover six beds. With three sizes, those same two sets per size become six sets in the cupboard to cover exactly the same portfolio. You triple the money standing still without sleeping one extra guest.
And the same happens with every dimension you leave loose
Bed width is the most visible one, but it is not the only thing that fragments stock. Each of these multiplies on its own:
- Mattress depth. Two 150 beds with 20 cm and 30 cm mattresses do not share a fitted sheet: the shallow pocket will not reach, and the deep one bags. It is the fragmentation nobody records, because both appear in the inventory as "150 fitted sheet".
- The pillow. A 45 × 90 case is no use on a 45 × 75 pillow. If you bought pillows in three batches, you probably have three sizes.
- Duvet cover or flat sheet. If some beds are made with a duvet cover and others with a flat sheet and a bedspread, those are two different systems of linen, not two references.
- Towel weight and colour. Two weights coexist happily in a cupboard, but not in the same bathroom: once they mix, the guest sees the difference and the team loses time separating them.
The four costs that come out of it
1. Money standing still
The most direct one, and the one we just calculated: more references, more reserve, more cupboard occupied by linen that is not earning a single night.
2. Running out at the worst moment
With one size, a laundry breakdown in August is solved by moving linen between apartments. With different sizes you can move nothing: the set going spare in apartment A does not fit the bed in apartment B. You have stock and still no bed ready.
3. Time and human error
Every extra size is one more decision for whoever loads the trolley, and one more chance of carrying the wrong fitted sheet up three floors. The cost is not the sheet: it is the trip, and the check-in waiting downstairs.
4. Replacement and continuity
The more references you keep, the likelier it is that one stops being made in the same white or the same finish, and the more often you have to renew a whole batch so the bed still matches. With few references, replacement is boring, which is exactly what you want.
How to find out what it is costing you
The sum takes an afternoon, with a sheet of paper and the inventory in front of you:
- List every bed space and every bathroom in every apartment, with the real bed width, the mattress depth, the pillow size and the towel sizes.
- Count distinct references, not pieces. A "150 fitted sheet for a 30 cm mattress" is one reference; a "150 fitted sheet for a 20 cm mattress" is another.
- Multiply by the reserve you want per reference. That product is your minimum tied-up stock.
- Do it again assuming you cut down to one double size, one single, one pillow and one towel weight. The difference between the two numbers is what the variety is costing you.
If your linen goes out to be washed, ask the laundry whether its rate changes by size or by type of piece: in many per-piece tariffs each format is its own line, and odd sizes tend to sit on the dearest one.
How to standardise without throwing money away
The temptation is to change everything at once. That is the most expensive way to fix it, because it means retiring linen that still works. The order that works:
- Standardise as you renew, not before. When a reference is due for replacement, replace it with the size you want to survive, not the one you had.
- Start with what rotates daily: fitted sheets, flat sheets or duvet covers, pillowcases and towels. Almost all the operating cost is there.
- Unify pillows before beds. Changing a pillow costs a fraction of changing a mattress, and it drags the whole family of pillowcases with it.
- When you do change a mattress, choose the size and depth you already have across the portfolio, even if there is a better offer in another size. The offer is paid once; the extra reference, every season.
- Leave colour and decoration per apartment if it gives you identity: bedspreads, throws, cushions. Those do not rotate daily and do not fragment the operation.
When not to standardise
There are cases where variety is justified and forcing it makes things worse. An attic with a bed built to fit, an apartment with bunks for families, a suite that sells precisely because of the big bed. The sensible rule: standardise everything you can and accept the exceptions deliberately, knowing that each exception carries its own reserve and had better have its own label and its own shelf.
The short version
Linen in use is set by the number of beds. Money standing still is set by the number of different sizes. When you decide which mattress to buy for the apartment you are opening next month, you are not choosing a bed: you are choosing how many references you will carry for the next five years.
If you want to work out the reserve properly before deciding how many sizes to keep, the PAR guide explains how much linen has to be in circulation and how much in the cupboard, item by item.