Dark living room and open staircase: entrance redesign or larger window?

[Mamalicious16]

We have a very dark living room and open staircase. Wondering whether to remove downstairs loo and have larger entrance with one door to living room and one to stairs ( as we don't like open staircases plus hopefully it will be warmer in winter). Then replace doors with glazed ones to make it lighter OR to replace double ( standard?) window with a triple one and just have stairs blocked in. Thoughts and any idea of price points?

Plus - do we need any permissions ( it's ground floor and development was built circa 2010 so all houses same age if that's relevant) AFAIK not in conservation area

Definitely don’t get rid of downstairs toilet. It’s a plus when selling.

A diagram would help @Mamalicious16, but @Fiddlesticks1 is right - definitely don't lose the downstairs loo!

I don't think you're allowed to change a house that currently has a downstairs loo to one that doesn't. So if you want to remove your current loo you're going to have to put one elsewhere downstairs.

Current layout https://www.barratthomes.co.uk/range/the-maidstone/

To this one

https://www.barratthomes.co.uk/range/the-ellerton/ ( ignore the cloakroom/ kitchen I'm just wanting the entrance like this

If you removed the loo you'd have to reinstate it before selling in the future. PP is right there a role I think about not removing a downstairs loo if the house has one. This is costly, so I'd rule out that option. Which way does the front of the house face? If it's north your light will be a bit softer and cooler.
Are you mid terrace or semi detached? If a semi could you add a side window? Even if it's obscured glass for privacy? Or one of those long high slot types?
If you make any changes to the front of the house that normally requires planning permission as it changes the street scene, but if you don't mind that another option would be to add a bay window, full bay, or oriel. This isn't usually very expensive, think of it like adding a miniature conservatory to the front of the house. It's just that the planning permission is a bit of a pain. Alternatively take out a few rows of bricks at the bottom and install a much larger window, again will require planning at the front.
Finally, do you have curtains or blinds? Seems obvious but do they pull all the way up or back, are you blocking any light with them?

Would you be able to add a porch? We had a similar layout to the 2nd. The original open plan staircase was boxed in and a door added so it was enclosed but we had a downstairs loo in the porch.

I've been in a house with a ground floor as per your second link. It worked well.
BUT im certain you won't get permission to remove the downstairs loo.
Im not sure about adding more windows across the front (is there even space to do this?).

I think you may gave to work with what youve got - but im with you about preferring the stairs not being open plan to a room.