You only needed an egress window if there is a bedroom. If there is no bedroom you don't need one but some people make windows larger to get more light in... As the look goes if the foundation surface is exposed enough above ground it is easy to make a larger window, if the ground level comes up high you need to make a well in order to have a large window. They make nice wells now that come as kits, or you can create a masonry well with a drain connected to it, some wells come with sealed well covers that can be opened or permanently sealed depending on the preference and how much you will willing to spend.

To give you an example, I'm designing a project right now for a customer, they did larger windows with a masonry well surround, but now they think to go for the whole "shebang" here is an example of before and after to give you an idea.

Before

After the window under the deck was also added it was a solid wall.

This is in the design stage

If you are building a new house then a basement requires at least (1) emergency escape and rescue window in addition to the egress route up the stairs.

If you have sleeping rooms in the basement, then each room requires an emergency escape and rescue window within the bedroom.

If you are remodeling an existing basement without an emergency escape and rescue window, then usually the existing small windows can remain grandfathered, unless you are adding a sleeping room, which would then require an emergency escape and rescue window. However it can vary per locale, as if you are finishing an unfinished basement (defined as storage), a locale may interpret code as a change of occupancy (to a habitable space) and require one installed.

@GN Builders L.L.C for your ^^ example house digging a lower patio along the existing back foundation wall, typically houses are built with the footing depth based on designed grade elevations and no deeper. So in your example, all the footings along the back wall, save for the corner of the sunroom, would now be exposed to frost heave in NJ.

@3onthetree I know that and I made the homeowner and his contractor aware of that, I'm just doing the design and a 3D visualization for them, they will have an engineer to design retaining walls, drainage, etc. As a matter a fact I think they found out the total cost of everything they are looking to make some changes, will meet them this week.

frost heave

Retrofitted exterior basement doors are not uncommon in old downtown portions of our cold climate city where every extra space becomes an expensive rental. When, as a licensed renovator, I advised clients of the risks, they inevitably moved onto less "negative" expertise.