The hon. Gentleman is making a very good speech, and I am nervous about intervening again, but will he accept this point? He talks about the noise pollution from living over a railway, and we know that private rented accommodation is a real problem. On the other side of the equation, very modern and expensive housing that is totally hermetically sealed could be as
dangerous, because it traps all the gases and pollutants within the home—not only carbon monoxide, but many other emissions.