The biggest levers
First come energy and staff. Both are fixed at the design stage and can only be influenced to a limited extent in operation: through the choice of equipment, through the length of the routes, and through how many pairs of hands a workflow requires. Second comes avoiding food waste.
How much is actually available here is shown by a study from Weihenstephan-Triesdorf University of Applied Sciences, which measured a real staff restaurant over 17 weeks. After the rebuild, energy consumption per meal was around a quarter lower and water consumption per meal was almost halved. Orders of magnitude, not a guarantee — but they show what is being decided at the design stage.
The study was carried out in cooperation with an equipment manufacturer. We therefore read such figures as an indication rather than a promise — and test them against the actual workflows in each project.
The cost driver nobody expects
Costs arise in particular from a kitchen or servery planned too large. That sounds counter-intuitive at first — more area feels like more possibilities. In fact every additional square metre has to be heated, ventilated, cleaned and served by staff journeys, for decades. Generosity in the wrong place is a permanent burden.
The same applies to the services
It is not only areas that are specified too large, but connected loads as well. The same study found that the measured peak demand after the rebuild fell by around a fifth — despite more powerful equipment. The reason: modern appliances only draw their full rating when they actually need it.
As a result the diversity factor — the share of the theoretical total connected load that is actually drawn at the same time — turns out lower than rough estimates suggest. That is not an academic detail: an overstated connected load means larger cable cross-sections, larger protection, more material. Costs that arise during construction and benefit nobody in operation.
That is why we calculate this figure for each project rather than by rule of thumb. It is one of the places where nothing can be corrected afterwards.
Why saving sometimes costs more
When cuts are made at the design stage, experience shows they hit the equipment nobody sees first. The result is regularly a deterioration in viability: appliances with higher consumption, workflows that tie up more staff, solutions that have to be replaced sooner. A saving in the investment that permanently raises the cost of operation is not a saving.
We therefore calculate what proposed savings mean in operation — so that the decision rests on a sound basis and not on the capital sum alone.