Summarize Multiple Worksheets Based on Criteria

Can someone suggest some code for me please as I have virtually no knowledge of VBA and I've been advised that a macro would be the best solution for my problem.

I want a summary list of data from all columns of worksheets that contain the target data and only where the value in col D is 1. So, in the attached example, the data to be checked is on Sheet1 and Sheet2 and the result should be shown on Summary sheet. There will be some tabs that don't need to be checked for the data so it's not a case of check all other tabs except for Summary.