Ludka and Brendan Powell explain the Welsh One Planet Development scheme and how it led them to building an off-grid, straw panel Passivhaus. Check out for more information.

Tom Gwilliam explains what Energy Performance Certificates (EPCs) are, how they are created and why they are unlikely to be a useful measure of how energy efficient a building is. Check out for more

Alan Clarke explains the role of a mechanical services engineer on a low energy house build, in designing a heating and ventilation system that works efficiently and is affordable. Check out for more

Andy Moger, from Tetlow King Planning, explains the role of a planning consultant and the benefits they can bring to a project. Check out for more information.

Beth Williams from Build Collective outlines the role of a structural engineer and explains what tasks might be undertaken on a house build. Check out for more information.

Martin Twamley from Steico explains how to use breathable internal insulation, while avoiding the risks of condensation and mould. Check out for more information.

As someone with no previous interest or skills in DIY, Passivhaus Consultant Es Tresidder explains why he went about changing that for his own deep retrofit project. Check out for more information:

Landscape Architect and Director of HLM Architects, Simon Bell, explains why he decided to upskill when it came to building his own house. Check out for more information.

Mark Siddall explains how thermal bypass or air movement around insulation layers might impact a self-build or retrofit project. Check out for more information.

Alan Budden explains how a phased retrofit might work and what preparation is required. He also shares how he's retrofitted his own home, which includes trialling an innovative roof solution. Check ou