Episode 08: Assessing the performance of your home

Get ready for a massive deep talk into the ins and outs of how the people behind the scenes calculate the performance of a home.

We sat down with Emilia Iacovino from Detail Green, who is not only a thermal assessor, but also a PHPP pro and an engineer with a passion for sustainability.

We spoke about the differences in assessing a house under the national energy rating scheme, and using the passive house planning package, as well as her insights on how these systems can – and should be – improved.

Spoiler alert – she is also currently getting her accreditation to become a passive house certifier, so I am sure this is not the last you will have heard from her on our podcast.

Episode Transcript

Sandra Redlich  00:00

Alright, so to be completely transparent, we have recorded an episode with our guest today before, but we figured we were losing out on the opportunity to have a real expert of this topic on and really drill her about the details of this and have this unique knowledge. So thank you so much, Emilia, again, to be on our podcast. First time for our listeners, second time for us, but very enjoyable to talk to you again. We wanted to take this opportunity and talk a little bit about the process of identifying the performance of a home because you have the unique skill set that you are both a thermal assessor and a certified passive house designer as well. And we want to get into today what the difference is, what that means and why that is important to homeowners. So yeah, could you maybe explain to our listeners quickly what it is exactly you do? I’ve kind of taken it away now but in simple terms or with more… Yeah. I mean, you know better what you do for a living than me. What is it that you do?

Emilia Iacovino  02:26

So I’m an energy efficiency consultant really, is the best description that is all encompassing of everything I do. So I, as well as what you mentioned, doing the NatHERS assessments for new builds and extensions, renovations and passive house design. I also do energy auditing for existing buildings. Which is, to me, just important to how to retrofit step by step for existing houses that are undergoing or existing commercial facilities that are going under for retrofits.

Sandra Redlich  03:04

Yeah. What does that exactly mean? So the energy audits and retrofit, for people who don’t know what these terms are?

Emilia Iacovino  03:09

Okay, so the energy auditing is where you review the electricity and gas usage of a site. And as you work out where the main source of energy usage is, and how you can reduce that usage, how much it’s going to cost to do that and the payback periods for them. A lot of grants to put in solar on buildings or to upgrade heating and cooling require an energy audit to be done first to gain access to funds. So some of it is for that, others is a part of a lot of businesses do it as a general way to look at costs cutting. So particularly for industrial and commercial, you know that it’s a big portion of their costs.

Sandra Redlich  04:03

Yeah. How did you get into that area? What’s your kind of professional background?

Emilia Iacovino  04:10

Yeah, so I originally studied electrical engineering. And I actually majored in high voltage power and control theory. And then I went to… I applied for a whole lot of manufacturing facilities, because I’ve just really liked the concept of taking something and turning it into something else. And robotics was what I was really interested in. So I ended up on the Ford Motor Company graduate program, and that was fantastic. So I actually ended up not working initially in manufacturing, I did end up in the design sector and working on low voltage and electronics. And that was great. And I did do some work in manufacturing as well, but not robotics, more on the actual assembly process. So more about process controls rather than actual control theory. So that was fine. So, I was with Ford for 10 years. And I was doing a house renovation and was very disillusioned with the information available on the energy of things. So electricity usage, etc. So, a friend was doing a master’s of energy efficiency and renewable energy at the time. And she said, You’d love this course, you’ve got to do it. And I had a look into it. And I thought, This sounds fantastic. So I did the course. And then I moved into some policy work, and then into energy efficiency work. So that’s how I got there. And for me, I feel that energy efficiency is almost more important, probably more important than renewable energy. Because the less you use, the easier it is to generate how much you need. And there’s obviously a whole lot of embedded carbon in renewable energy and in battery storage. So the less we need of it, the less resources we use to create it.

Emilia Iacovino  06:09

Yeah. So, I definitely feel that’s where my passion is. And so that’s why I kept… why I’ve worked in that field and continued in that field. So I originally started working with Luke doing energy auditing.

Sandra Redlich  06:23

Luke is your boss?

Emilia Iacovino  06:25

Yes. So Luke Plowman of Detail Green? And Luke’s the one who said, Would you like to get into doing thermal building thermal assessments? And I said, Okay. Because it’s another energy efficiency area that I haven’t been involved in.

Sandra Redlich  06:46

He ran in open doors it sounds like?

Emilia Iacovino  06:51

Yeah, definitely, definitely. So I would say my career path has not been a particularly planned one. And definitely lots more sideways than upwards. Lots of different experience and lots of people. And I’ve just, I love what I do. So I have done some talks at schools to encourage kids to do engineering. And although I just find, I think engineering is such a flexible career path, and particularly these days is a lot more also flexibility in the actual roles that make it a lot more easier for women and women and families, both partners, anyone who’s got kids. It’s changed quite a bit. And it’s also globally recognised. So I’ve had the opportunity of working in Japan while I was with Ford and, you know, unlike some other professions where you have to retrain, it’s fairly easy. If you have a degree from Australia, you can work as an engineer pretty much anywhere in the world. Yep. So that’s a fantastic opportunity, too. So many different sectors employ engineers, you can move across like I’ve done from one sector to another, the skills are transportable. It’s very important too, because when we have had the situation in Australia, where the manufacturing industry and automotive industry, unfortunately, have both had a decline that, you know, you need to move, you need a job that is flexible and that allows you to move industries.

Anthony Jenkin  08:29

Is this a public service announcement to, to call upon engineers?

Emilia Iacovino  08:34

Definitely, absolutely. And it’s a hard degree. I didn’t find it easy for studying. But I found the work experience was what kept me going because I loved the work. And I thought, if I need that piece of paper to do this work, I’m gonna keep going.

Sandra Redlich  08:56

It’s funny, my partner, who’s also named Luke, but it’s a different Luke, and he’s also an engineer. He keeps referring to what you described as not moving, having a planned career. He just says, I’m following my interests. And that’s what gets me to where I want to go. I just follow what I’m interested in and where my passion is. And yeah, it sounds like you’ve done definitely that. So you’ve talked about that you became a thermal assessor. Can you talk a little bit more about what a thermal assessment is, and how the process works to get an energy rating under the NatHERS scheme and what the NatHERS scheme is, maybe as well?

Emilia Iacovino  09:35

So the NatHERS scheme stands for the National Energy Rating System, and that’s what is commonly also referred to as the star rating system. So lots of people would have heard of six star houses, which is the regulatory minimum, which has been the regulatory minimum for over 10 years now. And if we think about how much technology has changed over the past ten years, it’s to me a shame that we’re still sitting where we were 10 years ago. But anyway, so the six stars is the minimum that you need. And how we do the rating is, you get the drawings from the architect, you need to be supplied, you actually need both the architectural and the structural drawing sets, because you need to actually check how the structure’s been constructed, in terms of how you assess the insulation for the floor. So, anyway, what we do is, there’s some really clever tools out there to do the assessment. But they’re quite manually intensive still. So, we have to import floor plans in, then you have to draw every room. And you have to draw every window and draw every internal door, you have to allocate every type of wall type. If you have differing wall type heights, floor to ceiling heights in different rooms, you have to add the extra walls in, you can only add one window in a wall. So if you have extra walls, you have to go into another tab and add the windows in there. It’s quite time consuming to draw this all up. There are unfortunately, at present no tools that automatically drag in CAD models into the system. And it’s not a 3D model, it’s just a flat model. So you’re also having to envisage how this looks in 3D on a flat model. So that’s one of its shortcomings, the labor intensity needed to do it. And so then, once you’ve allocated all the walls and window types, etc, the software then calculates how much energy is required to heat and cool every room individually. So there is some counting for airflow, natural airflow between rooms. There are some odd, in my opinion, things such as bathrooms, if they come off a hallway, or not conditioned, considered to be a conditioned space, even if you have heating in that room.

Sandra Redlich  12:34

What is a conditioned space?

Emilia Iacovino  12:36

A conditioned space is a space that is heated and cooled. So like being in living areas, bedrooms, etc. So it has, it’s very specific in the usage of each room. So you can’t just draw the rooms and say, these are all living rooms, you know, and these are all bedrooms, there’s different types of rooms, there is a living space, there is also just daytime spaces, and then bedrooms are considered only nighttime spaces. And so the amount of energy that’s considered to be used to heat and cool the rooms differs on how you allocate the room. So if the room has a built in robe, it can be considered as a bedroom, even if it’s going to be used as study. So, this is the thing, a lot of houses are built as a three bedroom or four bedroom house. But some of the bedrooms are used as studies and particularly recently, you know, since COVID, since the pandemic, more and more bedrooms are used as studies. So they’ve been heated and cooled all day. So there’s a bit of a… it doesn’t really consider the flexible use of a building or a room, it considers that the room has a specified use and that that usage will never change over the life of the building. So that’s one thing that I feel is unrealistic, particularly now. It was probably always unrealistic, but even more so now. And the other one is having bathrooms not heated or cooled. Because even if you’re building to six stars and still achieving six stars, you’re likely in colder climates in Australia, definitely going to have some heating source in the bathrooms. Also, when we’re talking about the heating and the cooling, it doesn’t actually consider what type of heating and cooling you’re using. So if you’re using the most inefficient gas ducted system on the market, or you’re using the most efficient reverse cycle system on the market, it doesn’t make a difference to the rating. So it’s not a whole of home. It’s only the actual thermal envelope. There’s no appliances considered and the same with the hot water system. You’re using the most inefficient gas storage system, or the most efficient electric heat pump system, there is again, no difference in your rating. So when people get their electricity bills, they’ll move into this brand new six star house and they’ll say, fantastic, I’m hardly going to use any energy. But if they’ve got a gas ducted system, they’re still going to have really high gas bills. And that is something that probably shocked people, and they might not be able to afford that. And I think that’s the real issue with NatHERS as it stands, and that’s one of the planned changes, is to make it into a whole of home. And that’s been something they’ve been trying to do for a while. And initially, the thought was, we’re not going to include appliances, because they get changed regularly, but heating and cooling and hot water services can last 20 years. And you know, that might be as long as people live in the house before they sell it. So to me that is really important. And heating and cooling is like 40% of the home energy use. So what system you use can influence your costs. So you are making the shell of the house as efficient as possible, but then using the most efficient appliances as well. That’s how you get true energy efficiency. It’s not one or the other. It’s the combination of  the entire system.

Anthony Jenkin  16:24

Sustainability Victoria have just released an online tool. So for anyone interested, you can track it down on the Sustainability Victoria’s website, and it allows you to import all of the appliances that are sort of in your home and get more of a realistic understanding of what those costs might be. I think that recent ABC article that was published this last week said up to 85% of Australians are experiencing bill shock. Or a term, Emilia, that you’ve also mentioned before that kind of translates to me is energy poverty. So it’s serious. It’s not just, you know, a thing that’s happening to a few, it’s 85% of this country, so is the approximate estimation.

Emilia Iacovino  17:11

Absolutely. And you’re looking at, you know, fuel poverty. We have a big issue in Australia in the cost of living with everything and fuel poverty, both vehicles and cars is the biggest issue I think we’re coming up to and you can actually also look on the CSIRO website, you can actually go and have a look at where all the NatHERS ratings are, you can actually go by suburbs, and see, you know, what percentage in one suburb are rated six star, seven star, eight star or five, four star as well, because you can get an exemption from a six star if you’re doing a renovation or extension.

Sandra Redlich  17:50

The Sustainability Australia website link, as well as the CSIRO that you just mentioned, we’ll put those into the show notes on our website. So people can can find those there. And yeah, maybe make use of these resources

Emilia Iacovino  18:05

Yeah, because it’s very interesting to see if you look, by suburbs, the wealthier suburbs have a high proportion of houses that are built at seven or eight, than the poorest suburbs. So you’re ending up in a situation with the people who can least afford more higher energy bills, or the people who are likely to be having higher energy bills.

Sandra Redlich  18:28

Energy poverty, right there.

Emilia Iacovino  18:29

Exactly. And the other main change that is on the cards is going from six to seven stars. And there’s a huge benefit to going from six to seven stars in terms of the reduced annual costs. And there has been some reports out there that saying it’s around $450 a year. I believe if you had airtightness, it could even get… that number would be an even greater saving. But the thing that I’ve seen in all the assessments I’ve done… Some of our assessments are just pure six stars, people just want to know what they need to do to do success. But the majority of assessments we actually do is how do I take this from a six star house to a seven star house, because there are a lot of people who are interested in having a more energy efficient house, particularly again after COVID, after being locked down, particularly Victorians after having spent so much time in locked down in our houses, and we’ve realised how freezing cold they are and how horribly hot they are. We definitely have that as the majority of the work we do now. And what we’ve really found is that the fundamental difference between a six star and a seven star house is the orientation of the house.

Emilia Iacovino  19:52

Yeah, that’s, you know, you can do a lot on the thermal side in terms of how much more money do you want to spend. If you want to reduce the amount of money to go from a six to seven star house, then you focus on the orientation in the design stage. That adds minimal amount of cost. So minimal amount of costs. I mean, today with all the CAD tools that are available, it’s so easy to change the angle of a house to make it suit better. And, you know, this whole fixation of having to have the house follow the line of the property. Now you’ve got a rectangular property and you build a rectangular house, and it’s exactly in the property. It’s parallel, everything’s parallel. And we need to get out of that. We need to get out. If that site doesn’t point North, don’t point the house that same way as the site. Angle the house, you know, you can do that, you know, and it’s not… It’s a lot less costly than when you’re trying to build a seven star house that’s been poorly oriented, because then you do need to put a lot more insulation. And you do need high performance windows. And this is what, you know, the people who have been arguing against seven stars have been saying, well, there’s all these incremental costs in the construction side. And that is only the case, if you don’t spend the time upfront in the design stage. Yes, you can say there are always site limitations, but there’s site limitations that put cost into the construction as well, that doesn’t stop people building on those sites. And a lot of the new housing estates, particularly in Victoria, are in flat Flatland. There’s nothing to do, there’s nothing that’s going to be a construction issue. It’s just spending that time rotating those plans. And to me, that’s the most frustrating thing, because I can do that. Like, I can see how easy it is if I get a plan. And I’m like, Why? Why is that bedroom facing North and the kitchen, the lounge rooms facing South? Like there’s no, there’s no constraint, there’s so many times where there’s no constraint on the property, yet the orientation is totally wrong. And understandably, if there’s a view, you want one window to have that view. But if the view is all to the South, and you face everything to the south, then yes, you’re going to have a really cold home unless you spend a lot of money on good windows and good insulation.

Anthony Jenkin  22:29

You’re coming off the back foot already. And I think that’s exactly why we’re talking about this, right? Because there are people who probably don’t understand the importance of orientating the home to the North.

Sandra Redlich  22:40

You’ve mentioned moving to seven stars. So just to make it clear, for the listeners, there is a planned increase in the National Construction Code to go from six to seven stars. I think it’s by the end of September this year 2022. So we have that coming up. That’s something good to report. But there’s something I wanted to make clear, because I think or I’ve realised in a lot of conversations people are not actually aware of this. You do put in certain performance factors and you do assess the house within the NatHERS software for your thermal assessment, but there is no actual in-person assessment that makes sure that the six stars that you’ve given that particular plan is actually achieved in the building. Is that right? Because that’s still blowing my mind to this day.

Emilia Iacovino  23:31

That is correct. So at no stage during construction, are there any mandatory checks that the correct installation has been put in, the correct window specification has been put in. All that information is contained in the NatHERS report. So my recommendation to homeowners is to ask for a copy of your NatHERS report. And check those items on site during construction if you are able to do that, because that can make a big difference to the actual performance of the house. There are also some other things that can make a difference to the performance of the house that are also not mandatory, which is to do with how the insulation is installed, ensuring there’s no gaps, etc. And also the airtightness of the building. That’s one area where there is the main difference between a passive house building and a standard construction, is that if you want to say yes, this is a passive house, you have to do a blower door test to confirm the airtightness. And that is also something that is not required in the star rating system. Even though it does make a huge difference to the performance and there is an optional requirement in NCC for airtightness. So you can actually put into a building contract requiring airtightness to be achieved that is in compliance with the NCC. And then you’d need to get a blower door test done to prove that. So and the good thing about it is to achieve the airtightness in the NCC, you’re using standard materials that you wrap houses with anyway. And these are those vapor permeable materials, which are also the best materials to use to prevent condensation issues, which have been in the news recently, again, and if you use materials that aren’t vapor permeable, such as foil backed materials, there are cases of houses of the wood rotting within seven, three to seven years after construction. So, airtightness is another aspect that home owners can option into their house. And it can be achieved using standard wrap material, it just has to be actually taped together and taped to windows and taped to the slab or glued to the slab. So it’s just a difference in construction methodology rather than materials. So obviously, there’s an additional cost in labor. But the material cost is almost identical.

Anthony Jenkin 24:25

We’ve spoken about the NatHERS software, the assessment is carried out for all homes and the requirements of six stars. But there is something else that can be done with passive house. And that is a passive house planning package assessment. Can we get you to just sort of maybe talk about your experience with PHPP, as it’s well known in industry with our nerds listening, and how I suppose… what’s involved in that assessment as opposed to the thermal assessment.

Emilia Iacovino  26:45

So the Passive House planning package PHPP is similar in that you enter walls and windows. But unlike NazHERS, where you have to enter all your internal walls and all your room types etc., passive house requires you only to enter the external walls. And that is because everything inside is considered to be airtight, and therefore it becomes one air volume, one envelope. And because a passive house is mandatory to have vented mechanical ventilation, the system knows that you can actually share the heat around the space. So you only have to enter… So a typical house that is a rectangle. So we’re looking at a house in a housing estate, they’re typically rectangular. So all I would need to do for the single storey house, I could enter four walls, that’s all I have to put into the PHPP. And again, I put the construction, and rather than having to select a specific wall that has assumptions built into it, in the PHPP, you enter the wall exactly as it is intended to be built. So it gives you a lot greater flexibility. And it’s much easier to take into account things such as with a concrete slab, you can’t put insulation underneath the edge beams or internal beams. And you can easily take that into account in the PHPP. It’s a really simple percentage calculation. In NatHERS, there’s nothing in the software to do that. We actually do a completely separate calculation and then adjust the inbuilt already set up system of the slabs to compensate for that. So it actually is more complicated in NatHERS to match what you’re actually constructing, than in PHPP, you can actually put in exactly in the lines, and it’s very easy. It just follows the standard wall build up, so you get the architect’s drawing, and it’s got the wall built up, and you just enter those items in there. And so it’s also really easy, it’s even easier to change the thermal characteristics of the wall or floor or ceiling to quickly see what you need to do to achieve passive house. And I think that’s also one of the downfalls with NatHERS. If I want to change all the windows from a typical aluminium double glazed to a typical uPVC, I have to go into a tab. We have to select all the walls, then I have to select all the windows and I have to… It’s a really complicated process. So every time I want to try a different window, I have to do that. Whereas in the PHPP I can… there’s actually a separate tab where I can actually set up all the different window types. And then I can just review each different type of model and see how the performance changes. So I’m not clicking here and clicking there and saving 100 files. I’ve got it all in one file. So it’s really easy to see how the performance of the building changes so there’s less that I need to input in the first place and it’s easy for me to see what I need to change plus, it shows me for every single window, the PHPP shows me what the solar gain is over the year for that window. So it shows whether it’s a positive overall contribution, or it’s negative. So I can say to a client, well, this window here is actually… you’re losing, you’re not actually gaining any heat over the year, so either make this window smaller or delete it. And that is, to me, the most powerful aspect of PHPP, because windows are so expensive. And yet, they’re so important in the thermal performance of the building. So you really want to optimize your windows, where you have them, what size they are. And PHPP enables me to do that. And the other thing that’s happened more recently is there’s now a design PH, which is a tool that works with a CAD 3D modeling tool called SketchUp, which a lot of architects already use. So architects can send us their SketchUp model, and we do have to redraw it. But it’s very, very quick. It’s like a rectangle, you draw a rectangle. And I’m someone who has not come from a background of using any type of 3D modeling tools. And I’ve managed to pick it up really quickly. Like with no help. I have to say, my colleague, Paul Gray, he picked it up even faster. And the same thing, doesn’t come from a background of using 3D modeling tools. And so SketchUp is a really easy tool for non 3D modelers to learn how to use, very easy to model passive houses in that, and then it exports it into the PHPP for you. So you draw the rectangle, you stick the windows in to the walls, and then you press send, and it fills out most of that PHPP for you. There are some bits that you still have to do manually. But the majority of it, you can actually do in this 3D modeling tool, you can select wall types that are already in the system as well, window types, etc. So also, what that means is if you’ve got this 3D tool, and somebody says, Oh, well, actually, I want to change the size of the house, which often happens in NatHERS, we’ve done this big model, we’ve told them exactly what they need to do to get to six stars, and then that’s during the design phase, or either concept phase or during the detailed design, then they get to their construction level drawing, and it’s completely different.

Anthony Jenkin  32:30

Sorry Emilia, I might just ask you to just outline the stages. So I suppose traditionally, in the industry, we would say that that assessment for a NatHERS assessment is done right at the end, it’s kind of like a tick box. But for us, you would recommend that that begins at the design phase?

Emilia Iacovino  32:47

I would recommend it at concept. Because the concept is the way the orientation is usually determined. And the initial layout of the rooms and adjusting that will have a huge influence on the energy star rating. So when we work with clients, we always do the first assessment at concept stage. Because you know, you can say to the client, well, to get six stars, because of your orientation, you’re going to need triple glazed windows. What are people going to do? They’re going to look back at the design and say, Well, how can we change the design? So rather than get to construction, we’ve already gone out to tender, this is what we’re assuming to use. And actually, what you’re assuming to use is not… You’re not going to comply. And then that will delay the build. So in order to not delay the build, which nobody wants, you’re best off to look at the energy performance of the house at the concept stage.

Anthony Jenkin  33:49

Yeah, so PHPP to me sounds like really design friendly. NatHERS not so much from what I’m listening to. I feel like it’s more important to have a NatHERS assessment done at concept than it would be maybe, then, you know, well, obviously PHPP is obviously very important as well at concept. But you know, it’s a bit more design friendly, or the user interface for PHPP might be a bit more friendly to write some revisions or changes then say NatHERS.

Emilia Iacovino  34:21

Correct. And I do have to say that I did listen, recently, there are some new NatHERS tools available that we haven’t tried, which might make it easier than the particular tool we use. So there’s a few different…So the NatHERS actual software that you put the input in, there’s a few that are licensed. So we use a particular one, and there’s some new ones that have just come onto the market. And from what I’ve heard, they’ve been more designed to make it easier to do these all these changes to optimise the design. So I’d have to put that caveat in that this is me comparing to the particular tool that we use, but I know a lot of assessors use the same tool So, yes, however, saying that I would still do a passive house design assessment at concept as well, because yes, the orientation, to an extent in passive house is important, but to a lesser extent. And that is the benefit, one of the real benefits of passive house is that the solar gain is shared within the building envelope. And what I mean by that is that, if you have a South facing bedroom and a North facing living area, then the warmth that is in the living area will be transferred to the bedroom via the ventilation system. So you’re sharing that heat gain. So the same thing, if you have to have the living room facing South, for whatever reason, because there’s a view to the South or view to the East or the view to the West, wherever the view is, you can then, if you have to have the bedrooms facing North, then you can take the solar gain, from those North facing rooms, whatever they are, even if they, you know, any living space, or even if their bathroom, actually, because the ventilation system moves all the air. And so you’re not having one really hot room, and one really cold room or one room that you have to heat and one room that you have to cool, because you’re spreading that heat around, or you’re spreading the cool around in some way, as well. So you’re ending up with a house that is at constant temperature, the same temperature in each room. And you know that that’s remarkable, really, you know, from my experience of all the houses I’ve lived in, in Australia, that I just, I can’t even imagine it, you know. So that’s the main difference, too, in the way the tools assess the energy usage as well, because the PHPP assumes that all that heat is shared. So you’re getting an assessment for the overall house, you don’t get a room by room heating, cooling load for passive house, you get the overall building, and you get the whole home because you also have to put in what type of heating cooling has been used, what type of hot water has been used. And if you want to get certified, you also need to put in all your other major appliances such as fridges, and ovens and stoves.

Anthony Jenkin  37:23

Yeah. Is there anything further that PHPP assesses or takes into consideration? Photovoltaics?

Emilia Iacovino  37:30

Yes, it does. Again, that’s one of the proposed changes for NatHERS is to take into account solar PV. So PHPP, yes, has a particular tab for that as well. And you can put in whatever system, so you actually have to put the specific system in. So as part of as well as energy efficiency work, I’ve also done work in renewable energy and doing costing and assessment of PV systems. And for clients who are looking at putting a PV system in. And one of the really interesting things is that different suppliers have different performance. So looking at the actual PHPP requires you to put in if you want to be satisfied the exact solar system that you are actually going to put into the house, not just a general five kilowatt system or a 10 kilowatt system or whatever you actually have to put the specifics in, you can just put to start with… That’s the other really good thing with PHPP, when you do the concept design, you don’t need all that information. So at the concept design, you put in generic heating and cooling information, generic hot water. So put in and use the same for PV, you can just put in the generic PV, so it’s got a lot of data in this Excel sheet. It’s amazing that you don’t need to know everything upfront. There’s all these window types already in there. There’s also a whole lot of drop down menus, you can select things from, so at the concept stage, you don’t need to know exactly what’s been built. It’s very much like NatHERS, you’re just selecting what’s already there. But when you get to the construction stage, you put in exactly what’s going to be there. So then the client knows exactly, that’s what exactly is going to be in there. And the builder knows exactly what’s going to be in there. And that’s one of my other issues with NatHERS actually, is that I can’t put in specifically what window is actually going to be put in because I can only put windows in that have a WERS rating. And a lot of windows don’t bother having a WERS rating and the WERS rating is a specific combination of frame and glazing. Now there’s hundreds of different glazing types and there’s thousands of different combinations. So I can have the same fixed window with I don’t know like 50 different types of glazing in there. So in NatHERS, you’d have to have every single one of those 50 combinations have a WERS rating done on them to have them in this system. And then that only gets updated at certain intervals. So the data is like a year old of what the windows are there, and window technology is moving so fast. And that’s the fantastic thing with PHPP. You can put in any different frame with any different glazing, and it works it out, and you can move those changes around. So you can say, well, you know this, and that’s actually what happens in reality, because when we get the quotes from the window suppliers, depending on the size of the window, there might be a particular type of glazing that’s required, or the size of the frame may change, it might change from 68 to an 88. So I can change those easily. And I can put in exact, it’s so much more specific, and so much more detailed.

Anthony Jenkin  40:47

Climate data as well.? So I imagine that PHPP has some very specific climate data, whereas there’s probably a lot of assumptions. And I know that for anyone who has experienced with NatHERS assessment, particularly in our area, there is a bit of frustration that our climate here is assessed, say with Ballarat, which we know in living or experiencing both of those places that that’s not the case.

Emilia Iacovino  41:09

Yes, there is a difference in the climate files that are used between passive house assessments and the NatHERS assessments. And yes, I can’t understand some of the NatHERS assessment climate zones either, like I did a project that was inland Victoria and the climate file was horrible. And I cannot understand how you can use a coastal climate file for an inland site. And yes, using something that is completely different altitude as well. And there is no adjustment for that. So whereas in PHPP, there is a limitation on how far the location can be from the climate file. And there is also an adjustment tool for altitude. And that makes a significant difference to the results. So we’ve, when we have a site that is equally distance between two climate zones for passive house, we’ll actually assess it using both those climate files. And we’ll take the worst case scenario. And that’s what we’ll take to the client. So and also the PHPP has got a new version coming out to version 10. And they’re going to have some exciting stuff in that I can’t give away too much of it. But I’ve been very lucky to be involved in the beta testing of that. And there’s some exciting stuff coming up from climate variation to look at worst case modeling with changes in climate due to climate change.

Anthony Jenkin  42:51

Sneak peak. I love it. Are you saying we might be able to forecast a little bit?

Sandra Redlich  42:59

Heard it here first.

Emilia Iacovino  43:00

Exciting. I’m very excited about it, because it’s actually something that some of our clients have asked us about, and they’re concerned about is particularly the overheating. You know, how are these passive houses going to deal? You know, everyone’s like, Oh, yes, it’s houses from a cold climate, it’s not suitable to Australia, what do you do with overheating? And so the overheating is something that we pay specific attention to in Australia. And because we do, so Detail Green do, because it’s something that we see as a future concern. And even if a house says it doesn’t need any active cooling, we will always tell the clients to install air conditioning to future proof the house.

Anthony Jenkin  43:48

Yeah, I had a client this morning, actually, that I was just responding to and asked the exact question like, is there anything we can do to be able to forecast? You know, with climate change in mind? So good to hear.

Emilia Iacovino  44:00

Yeah, very exciting. And there are some exciting changes happening within NatHERS as well. So, you know, the guys are on that have been working behind the scenes for a long time. So I’m, hopeful, you know, but they’re both of those new upgrades are supposed to happen by the end of this year. So it’s a very exciting year. From those two, from both perspectives. So I think, you know, I think it’s the right time to move to seven stars, we’ve already got over 10% of houses being built currently at seven stars. So it’s, you know, shifting the rest up to that level, and most importantly, shifting the people who are most in need of the higher performance houses up to that level.

Anthony Jenkin  44:46

Absolutely. I mean, I think maybe we might be coming across a bit critical of the NatHERS software, but because to me, I see that it’s still in its infancy, very, you know, has a lot of potential but PHPP has been around for longer is that, right?

Emilia Iacovino  45:00

Yes, correct. So the PHPP and passive house have been around for over 30 years now. And NatHERS has only over 10 years that we’ve had this. So it’s definitely in its infancy. And the good thing is, is that it’s got passive house to learn from and adapt, you know, and take some, you know, and the airtightness is one of the ones that they are looking at having no ability to put in there as well, so that we can see how the performance of the building changes as the airtightness changes. So they’re definitely being influenced by passive house in a good way. And right, you know, and also by changes in technology, you know, it is easier to achieve a seven star house now than it was 12 years ago, there was, you know, the same windows, you know, I really struggled. That’s when I first was… when I was doing my renovations and to find double glaze manufacturers in Australia, there was only people who did timber, and it was very expensive. All the uVPC products were all imported from Germany too, so they weren’t even made in lower cost countries. Now, it’s a completely different world. Now, there’s so many local manufacturers of high quality performance windows, that’s really shifted that market. So the ability to achieve seven stars. Yeah, it’s here.

Anthony Jenkin  46:26

I’m excited about the airtightness factor to be honest, because maybe we just give a quick comparison. So what does NatHERS assume for airtightness? I think it’s 10 air changes at 50 Pascal?

Emilia Iacovino  46:38

10 air changes is only the optional requirement in NCC, so I can’t see how they even assume it. So the standard house is around 30.

Anthony Jenkin  46:48

Wow. I say wow because I’m about to ask you, what is a certified passive house expected to achieve?

Emilia Iacovino  46:56


Anthony Jenkin  46:57

0.6 verse 30. How many times does that go in there? Someone could do the math. But yeah, that just shows you just how little air leakage is occurring and how much heat and cool is being contained.

Emilia Iacovino  47:08

That’s right. But it’s also really interesting to say how relatively easy it is to improve airtightness and retrofitting windows is actually the best way to do it. And I’ve seen that from experience. So I have a air monitoring system in my house, of course, and the CO2 PPM levels, since I’ve replaced my windows with double glazing, they are so much higher now. I actually have to open a window to ensure that I’m getting enough fresh air, whereas before I could have every single window in my house shut. And the PPM levels were the same as the outside air. So I had so much air leakage, that my house was being ventilated 24/7. You know, this is a 1970s brick veneer. So pretty standard build.

Anthony Jenkin  47:59

Yeah. And all that heat is going out with it.

Emilia Iacovino  48:02

All that heat going out, all that heat coming in, in summer,

Anthony Jenkin  48:06

All the energy required to provide that heat.

Emilia Iacovino  48:09

Exactly, exactly. So that’s right. And it got to the point, you know, where it’s a three bedroom place, and gas bills were $200 a month. And we couldn’t afford that. That was just crazy. And so you know, and that was five years ago. So I can’t imagine, you know, it was actually cheaper for us to get rid of the gas heating and put reverse cycle in. We are now at $100. And that’s through summer and winter. But yeah, so airtightness is not too hard to achieve, particularly in a new build, you know, we’re not talking about getting down to one, but getting down to 10. You can definitely do that in a new build using existing standard construction materials, just slightly modified methodology.

Anthony Jenkin  49:12

I mean, passive house, the name itself is probably a bit misleading because it doesn’t just mean we deal with houses. What are some of the other buildings that you personally believe would benefit from implementing passive house and the certification process?

Emilia Iacovino  49:28

Definitely all education facilities and childcare facilities and hospitals, and offices, basically every single building that has lots of people in it. Because what we’ve seen over the past few years is that, you know, viruses, airborne viruses, are very difficult to control. The measures we’ve had to put in place have had a huge detrimental effect on people’s mental health and our economy. So buildings that are healthy means that we can keep functioning as a society the way that humans love to function in social groups. And our economy can keep moving. And we’re reducing our health costs as well. Because if you’re not having people getting sick at work, because they’re catching something from the person in the office, three floors down, who’s sharing the same air, that’s been recirculated 50 times around, no fresh air. And the same with children getting sick in childcare, or schools, passing it on to people, passing it on to teachers, just ensuring you’ve got natural ventilation reduces the spread of colds, and also any other airborne viruses. Plus, if you’re ensuring sufficient oxygen, then you’re actually getting better performance out of people. So people are happier. And their productivity, which is a word that governments love to use, is improved. So you know, that’s why I think that passive house should be… or passive house principles, yeah, should be applied to all new builds in Australia.

Sandra Redlich  51:19

Just to wrap it up and ask you the one question that we ask everyone on this podcast, all of our guests. If you’ve had one free wish, what would be the number one thing that you would change in the building code?

Emilia Iacovino  51:34

There’s so many things, but I think some you know, some of them have been addressed, obviously, with the upcoming seven stars. And there is already some airtightness requirements in the NCC, I think the mandatory disclosure to me is the most important thing, because I think every homeowner should be given a copy of the NatHERS rating, because if it’s gone into that rating, and it is a really useful tool, it does tell you… It is a useful design tool in regards that it can tell you if you’ve got a room that’s going to have overheating or require lots of heating. So I would like every homeowner to have a copy of the NatHERS rating. And I’m really happy that it’s going to move to a whole-of-house as well, because I think homeowners understanding that their choice of heating and cooling systems and their choice of hot water systems are also going to have any large impact on their energy bills.

Anthony Jenkin  52:42

Yeah, I feel like we might need to have another chat after the whole-of-house is in effect, and you’ve had some time to do a few projects to get your feedback.

Emilia Iacovino  52:52

Absolutely. Absolutely. And by then hopefully I’ll be a passive house certifier as well. So then we can chat about that as well.

Anthony Jenkin  53:10

This is a massive year for you. This is great.

Emilia Iacovino  53:13

Well, thank you so much for giving me the opportunity to chat to you guys.

Sandra Redlich  53:19

Well, thanks for sharing your knowledge, your experience. And yeah, explaining these two systems. And thanks for the work you’re doing. I think, yeah, that can’t be said enough. really doing a big, big, big, big part of making sure that people have better and healthier homes, and we have less polluting houses, actually. And, yeah, more energy efficient homes to live in. So thank you very much for your time. And yeah, we’ll chat to you once you’re a certifier. And that’s a whole new, whole new thing that we can talk about, and maybe who knows, some of your wishes have come through by then and we have some better regulations.

Anthony Jenkin  53:59

Thank you, Emilia. Yeah, I really appreciate your time and your expertise as well and till next time, I guess.

Sandra Redlich  54:05

Thanks for listening, and until next time.