Hi Berndt - to explain - you take the empty weight of the vessel and multiply it by the cost per kg to get the total cost of materials, ditto for length and build time. i did a quick spreadsheet using some of your designs as an example.
Boat Weight Length Cost per kg. Cost per Meter Materials Cost By Weight Materials Cost by Length Build Time per kg Build Time per Meter Build Time by Weight Build Time by Length
Duo 425 44 4,25 $35,20 $1 476,38 $1 548,80 $6 274,61 3,3 157,48 145 669
Duo 480 180 4,8 $35,20 $1 476,38 $6 336,00 $7 086,61 3,3 157,48 594 756
Eco 5.5 289 5,5 $35,20 $1 476,38 $10 172,80 $8 120,08 3,3 157,48 954 866
Eco 7.5 750 7,5 $35,20 $1 476,38 $26 400,00 $11 072,83 3,3 157,48 2475 1181
Duo 8000 830 8,25 $35,20 $1 476,38 $29 216,00 $12 180,12 3,3 157,48 2739 1299
KD 860 1800 8,6 $35,20 $1 476,38 $63 360,00 $12 696,85 3,3 157,48 5940 1354
KD 122 3100 12 $35,20 $1 476,38 $109 120,00 $17 716,54 3,3 157,48 10230 1890
Harryproa 40 800 12 $35,20 $1 476,38 $28 160,00 $17 716,54 3,3 157,48 2640 1890
Sorry that the table doesn't copy across properly aligned but i have manually aligned the first row to help understand it.
What is clear, I think, is that in general there is a better correlation between weight and materials cost than length and materials cost but that length surprisingly gives a better correlation to build time. Where there is a big variance between build time calculated by weight and build time calculated by length e.g. for the KD 122 by weight build time is calculated as 10230 hrs and by length build time is calculated as 1890 hours I would tend to view the length value as an under estimate and possibly add 50% or more to that value giving a build time of 3000+ hours.
