Believe me, they’re much better clean. The limestone ones, when the sun shines “just so”, seem to be made of gold - which is probably on purpose, considering when they were built Manchester was the centre of the world, richer than London or most other places on Earth.

Better architects of the period understood the effects of soot and played to them. Because houses were heated with coal it was a problem even before the industrial revolution. As such, some architectural historians believe that buildings shouldn’t be cleaned for that reason.

Here is a painting of how the Cologne cathedral looked shortly after its completion: http://www.altertuemliches.at/files/langl_dom_352613_01_kl_0...

During the WWII bombings, the cathedral was damaged at the front, which was repaired only recently. The original color can also be seen there: http://in0.bilderbuch-koeln.de/bilder/k%C3%B6ln_altstadt_nor...

As you can see, the repaired area is already blackening again. AFAIK, this is inevitable with this kind of stone.

10 Downing Street in London was similarly yellow darkened by soot. During the refurbishment they decided to paint the yellow bricks to maintain the classic look of the building.

See https://en.wikipedia.org/wiki/10_Downing_Street#Rebuilding:_...

As do I. I always like old industrial cities in the north of the UK for the unusual character they have due to the black buildings. I’m sure some buildings look better cleaned, but I hope they don’t get carried away and remove the unique character of these cities.

Do you actually live here? Black buildings under a dark sky most of the year -- it gets really depressing. I am grateful for the red-stones, old limestone buildings getting cleaned, and new ones adding some color (quite a bit of yellows and whites recently, among the inevitable onslaught of glass and steel).

Yes, without going into too specific details to maintain privacy I have spent most of my life in northern industrial towns. I can see the argument for it being depressing, and I dont think they shouldn’t be cleaned at all. What I am saying is that I hope some particularly impressive buildings are kept black to maintain that character. Cleaning some would provide some variety and I have no problem with that.

I grew up thinking most of them were intended to be black, like St Peter's Square and the town hall. Seeing them cleaned was initially quite odd.

Considering the industrial heritage I'd also like to see a few preserved that way. I'm just glad I grew up after the clean air act!

They are slowly cleaning Cologne Cathedral.

Try the Hold Saviour Church in Gyumri, Armenia, which is built from black and orange stone. It's close to the Cathedral of the Holy Mother of God, also black.

https://commons.wikimedia.org/wiki/File:Holy_Saviour_Church_...

https://commons.wikimedia.org/wiki/File:2014_Prowincja_Szira...