Why do you think it will look funny. What r u proposing to change them too. Double glazing will help with mould and temp control over old single pane glass

Okay, so you have how many windows on the ground floor? 4 (Four) windows on the second storey. I would be checking why mould has been accumulating . Is it a ventilation issue? What type of windows are you changing to and what material, timber or aluminium? Are you also going to change the front door and it’s side windows? Are the existing windows timber? Yes the windows would look good if they are all the same. But from your photo you can’t really see the ground floor windows anyway, so if these do need replacing, it won’t be a big deal. But if you are replacing the second storey windows, then all 4 second storey windows need replacing at the same time.

Why replace 3 windows on the top storey if there are 4 windows?

And if the ground floor have mould and “not in good shape “ why are you replacing the top floor windows?

sorry, a typo. I meant to say there are 4 on the second storey which need replacing as they hit the sun the most and possibly from moisture/condensation. it is a dated house built in 1970s. The ground floor two windows are larger ones either side of the door are semi hidden, and they are in better condition most likely due to being more hidden from the undercover patio area.

the door will be changed with the two panels on the side.

So hoping to change the top 4 to still panel/white windows but less squares and more modern.

Would it look not as uniform and lessen curb appeal?

thanks in advance

Have you tried seeing if the grids are stuck on strips or separate panes of glass, we had metal window frames with metal strips to give the appearance of a look like yours, we removed the strips to have large clear windows, made a huge difference and they would match your new 4 top ones.

And no AI. :)

Original poster still hasn’t said whether the existing windows are timber or aluminium. And what they are being replaced with. Being a 1970 house, that was the cusp of timber being used less often, and more using aluminium windows.

Yes it is metal. if the strips are removable that would be great, i will look into that!

Looking into replacing with aluminium or uPVC.

I would say your windows are aluminium already. Makes me wonder why they are damaged by mould. With aluminium windows, they would need a good clean to remove mould, not need replacing. Timber windows can get wood rot from condensation, but aluminium windows just need cleaning and wiping down. Is your upstairs timber stud walls, or brick?? Maybe, if timber stud walls, condensation has got into the wall timber, ,not the windows. Therefore the walls would need fixing. Not the windows.

Or, do you have timber window sills? These may have mould damage.

Rust is on the window frame, and will sills have rot as its timber. I will get a carpenter to check if they are fixable and go from there. thank you for all your advice. much appreciated

Yes, I think that would be a better direction to head in. Get the wood rot fixed first. In the mean time if your windows have condensation, wipe them down each morning to remove condensation. The rust can be cleaned off windows. Clean rust (often white, powdery aluminum oxide) from aluminum windows by scrubbing with a paste of lemon juice and baking soda or a 50/50 white vinegar and water mix. For stubborn spots, use fine steel wool, a soft wire brush, or crumpled aluminum foil, followed by a thorough rinse, drying windows after doing this. I would be getting another window person in to see if they really do need replacing.