RowHeight Property
Returns or sets the height (in points) of all rows in the specified range. Returns Null if the rows are not all the same height. Use the IsNull function to determine whether the return value is Null. Read/write Variant.
expression.RowHeight
expression Required. An expression that returns a Range object.
Example
This example sets the row height to 15 points for rows 1 through 10.
Spreadsheet1.Range("a1:a10").RowHeight = 15