Inquiry into ‘Low carbon housing: the challenge’ – first evidence session

Jan 24, 2018 | Articles, Assembly Business, Cardiff, Cardiff Housing Issues | 0 comments

Plenary 24th January 2018

09:32
Watch on Senedd TV
Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Thanks. Could the panel actually just clear up exactly what a passive house is?

Chris Jofeh

It’s—

David Thorpe

Sorry—do want me to give you the technical specification?

Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Well, possibly not that, but it’s a new concept for me. I just want us to all be clear that we know what it is.

David Thorpe

It’s about the overall energy use per square metre, to bring it right down, and it’s also about airtightness, which is measured by the number of air changes per hour. So, you need a blower door test to measure that. That means that, in practice, you have to do things like control thermal bridging very rigidly; there’s no thermal bridging allowed where heat can travel from the inside to the outside or vice versa. It has to be very airtight and ventilation is, therefore, controlled. All aspects of energy use are also minimised as far as possible and the heat is captured from things that happen inside the house—the occupancy, the technology inside the house and any solar energy that’s captured—but mainly it’s about superinsulation.

Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Right. So, you seem to have differing views on whether or not we need to adopt Passivhaus standards. You were more enthusiastic—

Chris Jofeh

Enthusiastic about what it achieves. I don’t think it’s the only way of achieving it. I’m sorry if I wasn’t clear about that.

Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Right, okay. So, what does the panel think are the standards Wales should actually be aiming for, and why, from the variety of different options like near-zero carbon, Passivhaus, near Passivhaus, energy positive? What should we actually be aiming for as the standard in Wales?

Chris Jofeh

I think zero carbon, in operation, is a reasonable and achievable goal. It may, in certain circumstances—depending on location, orientation and surrounding buildings and so on—be possible to be energy positive and that should be encouraged, but I don’t think that should be required.

Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Okay, thanks. Would you like to give your view?

Dr Joanne Patterson

I would agree with that, yes. I think the context can certainly have an impact. If a house is in a close valley and the climate is not positive, then that can really impact, and make it virtually impossible to achieve Passivhaus.

Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Okay. Thanks for that. And David, what do you think?

David Thorpe

I think trying to get zero carbon over the entire life cycle of the building is the way to go. I mean, in one planet development, the planning guidance says that that’s exactly what these buildings have to be. So, you look at the entire life cycle, from the materials, the construction process, the occupation process and taking it down at the end. So, there has to be a plan for the building in that context. That is a planning requirement for one planet developments.

Gareth Bennett AM

Gareth Bennett AM

Party: United Kingdom Independence Party (UKIP)

Thanks.