Insulation Council Handbook A handbook, available at the link, which gives calculations for various parts of a house with combinations of insulation materials.
An On Line calculator to work out what size water tank you need – Provided By Stratco
There are several downloadable span tables for decks, pergolas etc at Thora Timbers so if you live close to Brisbane check them out
Timber Retaining Walls
Queensland Design Guide
Windows (Double Glazing)
You can check the performance of various manufacturer’s units at WERS (Window Energy Rating Scheme)
Stratco Guide to Estimating Wind Speed