Parisian Building – Watercolour and Inktense

After my recent post, which has contributed towards a lively discussion, I include a further “building”. Its from a photo, taken in 2006, of one of the building visible from the cruise barges on the Seine. I was going to comment on its structure but will leave that to others but, perhaps, someone might recognise it and allow me to put a label on it. Its near Notre Dame Cathedral and is on the same side of the river. Can anyone tell me why the buildings have such high pointed roofs? Is this the same principal as building a cupola for cooling the insides? Surely its not for aesthetic purposes only?