The person that designed the house should be able to answer your question, if they exist.

Are these between the glass? Removable interior grilles?

They are SDL

Internal spacer bar with applied interior and exterior grilles then? Will the windows all be casements? Patio Doors?

Exterior view of house might help

Not an answer, but if that was my view, I’d want it unobstructed.

Casement. Exterior view if this helps!

If you like the treatment on the already-built house, can you visit it and see what they used?

I find grills in a window can have a positive effect on the appearance of a home and have a tendency to 'disappear' when viewing out a window. They can be used to help define the separation between indoors and outdoors.

I agree, whereas without grilles, especially on a traditional or transitional home, the windows wind up looking like black holes.

Carry the grill layout in every window in the house where appropriate. I designed a Prairie Style home with Prairie Style grills throughout the home, but the client only bought windows with grills on the front of the house.

Absolutely all windows should look the same.

BTW: Pretty house.

Yes, definitely a very nice-looking home!

Hopefully the pleasant aesthetics of the house is carried all the way around the house.

Yes, all windows will have grilles! Just can’t decide between 5/8” or 7/8”!!

Again. it is a personal choice. I prefer the 7/8", which is more popular and substantial. I have always referred to the 5/8" as more historical, as that is frequently in 100-year-old homes.

I just measured mine. My house is craftsman style and it's 7/8". I have grilles only on the top half to play off the craftsman look.

For your house it really has a more traditional feel, so I'd go with 7/8" to play it up. I think 5/8" will look too skimpy.

What brand window? Do they have the "internal spacer" to give it the true SDL appearance? I am surprised those are your options. 3/4" is more common from what I recall.

Lincoln with internal spacer.

I would ask if you are sold on Lincoln but I will assume so. Is the 5/8" or 7/8" the exterior/interior grid or the width of the internal spacer? If the interior/exterior grille I would for casements and a modern house go with 5/8".

^^ except her house style leans more traditional with the rafter tails and the overall look

Ok, but still with casements I prefer the thinner grille (or in this case muntin).