Change Image Heights

I have seen this question asked a few times now and not answered. There doesn’t seem to be a way of setting the image height (to suit a specific aspect ratio).

I tried this in CSS but it made the rows overlap as their heights seem to be calculated during the grid build.

I also tried doubling a row in the grid builder, but that just made the images too large in height.

There needs to be a way of setting the height of each row to preserve certain aspect ratios. Does anyone have a solution?

The page I need help with: [log in to see the link]