Jake White from Ecotecture shares the story of The Curly House, an award-winning project that was built using insulated concrete forms (ICF). He explains what an ICF is, why there are benefits in terms of speed of construction and durability, and why most concrete structures have the potential to be extremely airtight.

Rory Bergin from HTA Design LLP explains why building standards are devised, the pros and cons, and why people adopt voluntary standards. He also gives an overview of the Active House standard.

Dusty Gedge, founder of Livingroofs.org, explains the benefits of installing a green roof, how it can be simple and why lots of people get swayed by commercial systems.

Graham Hunter from Parity Projects explains how data collected from one of their energy assessments is then turned into a report of options for the homeowner. This follows on from episode 60 which trailed Graham as he conducted an assessment.

Stephen Gurney from Ecological Building Systems explains the main causes of poor airtightness test results.

Alan Budden from Eco Design Consultants explains how simple design decisions can drastically alter the energy performance of a house and why this means your designer needs to be using a tool like the Passive House Planning Package (PHPP) to better inform these decisions.

Ken Levenson from 475 High Performance Building Supply explains what overheating is, why it happens and how to deal with it.

Doug King explains what smart energy systems are, how they work and whether we should be embracing them in our new homes.

Building services engineer Alan Clarke explains what factors should be considered when choosing a heating system for a low energy home.

If the idea of going 'off-grid' excites you, then perhaps now is a great time to be doing it. We live in an era where the cost of items such as solar panels is continually dropping and this is juxtaposed with fossil fuel reserves that deplete day by day.

While you may even be forced off-grid if you move to a remote location, does it make sense going off-grid if you have perfectly good access (for example, in a town or village)? And with different grids -transport, gas, water - which is the easiest to unplug from?!

In this discussion (which was one of our Google+ Hangouts) we discuss some of the issues surrounding going off-grid.

The Panel

Mike Coe, who lives in the Cropthorne Autonomous House (and was our guest in episode 54).

Paul Scheckel, author of The Home Energy Diet and The Homeowner's Energy Handbook.

Ken Silverstein, an business journalist who specialises in writing about energy