Performance / Space implications when ordering SQL Server columns?

Question

Are there any considerations that should be taken into account when designing a new table with regards to the order in which columns should be declared? I tend to put the pr

Answer 1

SQL Server stores the data on disk in set and fixed fashion.

The order in sys.columns and key columns has no relevance to this on-disk order.

See "Anatomy of a record" (Paul Randal) and my answer here: How do you get to limits of 8060 bytes per row and 8000 per (varchar, nvarchar) value?