i'm looking for a evergreen architectural ball type plant

Boxus sempervians is a hardy one and ideal for this purpose. You can buy them already shaped or do it yourself.

I see you didn't want Box - how about a Bay - larger leaved, but can be kept shaped, though admittedly they're usually a standard with a ball at the top. Otherwise, you could try Lonicera nitida - there's a yellow or a green version, small leaved, tolerates constant clipping. Depends how small you want it, really. If you want it really small and not a standard, why not buy Hebe Green Globe - sticks to a globe shape all by itself, evergreen, hardy.

And now I've realised where you live, you might want to check whether the plants I've suggested are hardy enough for where you are.

Pittosporum tenuifolium 'Tom Thumb' is perfect for this.
Its new growth is green and as it matures, over a weeks it slowly changes to a bronze colour.

It's ultimate height is 3' but simple and easy to keep in a shorter/ smaller ball shape.

I have them and they're a great looking little evergreen shrub.

Louise I have a larger version of Pittosporum and they are great lookers with a pyramid shape. The Tom thumb ones must make lovely balls I just want to ask if left to be 3 ft is their shape good?

Very good, Denise !
I don't even have to prune mine, just the odd snip here and there.