Deborah and Fliss grill the boss of Barratt Homes about the company's promises to build greener homes. They discover cement is far more interesting than they'd ever imagined. Did you know it's responsible for a staggering 8% of global CO2 emissions? They find out why it is so hard to decarbonise and what progress has been made so far. And if you've ever given the side-eye to someone sat in a parked car with the engine still running, here's your vindication: Deborah and Fliss find out what impact idling engines have on air pollution and what's being done to encourage construction workers on building sites to change their behaviour. They hear about some of the frankly astonishing reasons construction machinery can be left idling, including workers using lorries and digger engines to charge their phones.
With Deborah Meaden and Felicity Hannah.
This is the last show of the series. The Big Green Money Show will be back in October. If you haven't already, please subscribe and then you won't miss us when we return.
Production team: Lexy O'Connor, Luke Wilson, Gareth Jones, Natasha Johansson, Justin Bones
If you'd like to get in touch with the team use #GreenMoneyShow on Twitter or email GreenMoney@bbc.co.uk