I doubt your profit margin per ticket includes over head costs. Is sounds like it’s mostly direct costs that are included. If your shop truly had a 70% profit margin the owner would be loaded, for every 100k you charge customers they would be taking home 70k in profit.

Not sure if you are being sarcastic and think 8% is huge or you are being sincere and think 8% is poor. 8% is average compared to other industries.

I see you got as far as supply and demand in your economics course before you zoned out. Competition specifically 3 competitors has been shown to apply sufficient pressure to stop price gouging. Airlines profit margins are at 8% which indicates sufficient completion.

You can back out R values based on insulation thickness, that table may be old… It didn’t have a date on it.

The values you provided equate to freedom R values of R40.5, R28, and R22.5 for the roof, walls, and floor. Those are inline or behind the US minimum requirements R60, R30, R20.

I was using freedom units for both. The R values were determined based on insulation thickness. Because you Europeans use energy consumption for your requirements it’s impossible to compare with US requirements. I did find this table giving recommendations for insulation.

https://www.new-learn.info/packages/clear/thermal/buildings/building_fabric/properties/insulation/images/slide4.gif

The insulation requirements in the US are higher than many European areas with similar climates. Germany for instance would fall in region 4 and 5 of the US climate wise. R-30 is required for walls, R60 for ceilings, and R20 for floors for homes in the US. Germany recommends 6cm of wall insulation ~R8, 14cm for ceiling ~R19, and 6cm for the floor R8.___