Is it OK to break consistency in my page margins?

I am a beginner and designing my first UI wireframes for a large website with 80+ screens. My question is we set a margin width for the pages of 100px on each side of the page (the screen sizes are 1920px in total width). Is it good practice to stick to this margin throughout the project? Many of the pages contain a side menu and detailed forms and it would make more sense to reduce the margins on these particular pages for more room regarding the form data. So the question is: is it ok to have different margins on some screens of the website? Thanks