Your page layout has a great effect on your website like for example driving loyal audience to your campaign.
Yes its a ranking factor. If you have great page layout, it will help your user experience. It will improve conversions and user engagement with your site. Effective page layout helps Google to understand your site content, information flow and user behavior. So Google will pay you back.
There is a tool in Google analytics that will show you problems with your sites layout and specifically the header section. If your content starts below the accepted threshold because you have a large header or you are displaying too many ads, that could be a major ranking factor.