Ah, thanks for that, @bpcyclist But our architect is the best designer and he suggested the gap in-between our properties could have a turret design. That would stylize the property beautifully, and as engineering bricks are so expensive now, he suggested the 'industry standard' engineering brick - Flettons. Curious I looked them up and found a bunch of similar bricks, even Portland Stone, but that stone would cost a fortune. Providing cement covered them (I presume using a lath wire mesh), then the exterior can be painted in the same colour masonry paint. Our architect recommended Farrow&Ball because it's excellent properties are eco-friendly. I never thought of that.

Thank you very much for your suggestion.