Hans wrote:

quick and dirty:

\setuphead[chapter][before=\vbox to 10cm\bgroup,after=\vss\egroup]

\starttext

\chapter{test} \input tufte \chapter{test\endgraf test} \input tufte

\stoptext

there are other solutions (synchronizing stuff) but that's more complex

Great! This solution worked for me. I have added it to Sample Macros in the Wiki. Thanks, Duncan