The podium and the walkways are surfaced with bricks. According to Chamberlain, Powell & Bon, bricks are “a material, technologically and historically intermediate between wholly natural (the ground) and wholly man-made (the towers)”.

I have to say that I personally find this pseudo-philosophical explanation peculiarly satisfying. But I suspect you would be just as entitled to laugh out loud.

But I am for it. The consistent use of the Barbican’s brown bricks does mark out the podium – in fact, all the various pieces of the whole estate – as belonging to one group. It’s like a school uniform. I like the theory of the earth of the gardens at one end of our Barbican spectrum and industrial concrete at the other end, linked by bricks traditionally moulded from earth, and transformed by fire into something quite different and technological. In fact, I believe they are called “technical bricks”. If you like, there is also a visual transition in colour and texture between the natural colours of the gardens and the grey of the buildings.

Of course, it would have been so much easier for the City to have covered the whole area in a ‘cake icing’ covering of tarmac or concrete. Imagine the labour of laying all those bricks. They are not all just flat bricks. If you look at the edges round the lake, or where they become ventilation shafts on Beech Place, you will see that the edges are moulded into special curved shapes. This is even more pronounced when you look at the edges of the flower beds inserted into the North Barbican area in the shape of fried eggs. What an absolute labour of love the Barbican was to construct, not just on the part of the architects, but clearly on the part of the City itself. Over the years, many areas have had to be repaired or replaced. They have not been able to exactly replicate the original bricks. In fact, in many areas they have switched to bricks with a scored surface to avoid people slipping or sliding in the wet. They have had to do a lot of work round the lake. One day the accountants may strike and repairs will be made with tarmac. I desperately hope not.