Lightweight Bricks

An Autoclaved Aerated Conrete block or lightweight brick, is essentially concrete with lots of little air pockets. According to Wikipedia, AAC was invented in the mid-1920s by the Swedish architect and inventor Johan Axel Eriksson. But it only became a popular building material world-wide in the 1980's. To me, it looks like a rectangular block of hardened meringue.

The wall - notice the size of the normal brick sitting on top of the wall

The wall separating the house and the back-lane is being rebuilt using this material. The reason for using this "brick" over conventional clay bricks is the need to lighten the load on the site. Indeed, these blocks are light - scarily light. The wall swayed when I touched it while it was being built, but thankfully stiffened when the concrete columns were erected later, effectively bracing the ends of the wall.

AAC blocks will also be used for all the walls dividing the rooms. Because they have so much air in them, they are very effective thermal and sound insulators, perfect for hotel room walls.