We're in a time machine. For some reason best known to us, we go to Ancient Rome and kidnap a builder. It's cruel. He's terrified of our world. Horseless chariots, giant metal birds and children tied to moving-picture writing tablets. What Tartarus is this?

Then it gets better. It's Monday morning. We take him to a building site. He picks up some bricks, mixes some concrete (which he invented) and starts work straight away. There is something wrong with an industry still recognisable to the ancient world. It's time we changed it.

Modular building technology gives us the chance to do so. It means you can factory build complete houses with computerised machines. You can build a semi-detached house to last a hundred years, in 14 days.

If the government focuses on modular solutions and joint ventures with the private sector, we can build over our housing gap in five years. We can also send home our Roman builder, because construction will have finally emerged from the ancient world.