Create an additional column, say H, with from H4 on:

=SUM(D4:G4)

and invoke:

=SUMPRODUCT(--('Planned Kilometres'!$A$4:$A$109=1),--('Planned
Kilometres'!$B$4:$B$109="P"),'Planned Kilometres'!H4:H109)

Steved wrote:
Hello from Steved

Below is fine for D4:D109 but if I change it to D4:G109 it shows #VALUE!
My objective is to sum the extra 3 columns.
What is required please to have it working.

=SUMPRODUCT(--('Planned Kilometres'!$A$4:$A$109=1),--('Planned
Kilometres'!$B$4:$B$109="P"),'Planned Kilometres'!D4:D109)

Thankyou.

--

[1] The SumProduct function should implicitly coerce the truth values to
their Excel numeric equivalents.
[2] The lookup functions should have an optional argument for the return
value, defaulting to #N/A in its absence.