Transforming Timber Sustainable Design for Modern Living | Milli Studios Lalor Park CLT Home
Our recent site visit to the Milli Studios CLT Home / Passive House in Lalor Park gave us an insightful look into how modern design principles and sustainable materials, like Cross-Laminated Timber (CLT), are transforming residential architecture. The structure, designed to Passive House standards, is an excellent example of using CLT for its structural integrity and sustainability. As the CLT panels were craned into place, we could see how the material not only provided a simplified construction process but also allowed for precise detailing—essential for achieving the energy efficiency demanded by Passive House criteria. The result was a home that marries environmental consciousness with a modern aesthetic, offering both comfort and durability.
During the visit, we explored the home’s clever use of natural light, insulation, and modern materials, with a particular focus on the roof and wall systems. The external cladding and thin, sharp roof eaves created a streamlined, minimalist appearance, while interior skylights and large windows ensured the entire home felt bright and spacious. The CLT panels formed the backbone of the house, and it was impressive to see how they allowed for an airtight, weatherproof shell, cutting down construction time and ensuring long-term durability. By designing the home with such efficiency in mind, Milli Studios created a practical yet beautiful dwelling that demonstrates the future potential of CLT construction in sustainable housing.
Transcript of site visit to Milli studio’s CLT home below:
Streamlined Structure: Exploring Cross-Laminated Timber (CLT Home) and Modern Design Principles
 CLT for those who don’t know is the sense of cross laminated timber and it’s basically a thick panel of plywood . So in this case it’s a 90 mils structural wall panel.
The entire house it’s full timber panels that kind of click into place almost like a lego set. When the CLT gets put in, windows are fixed in quite simply as well directly into the CLT. You get not waterproof but weatherproof kind of shell, which is great because it means that the protection that we provide to it, it’s more or less for long-term durability.
The whole CLT was a substrate, essentially. These battens serve two purposes, one, clamping the insulation in place permanently and also they form the battening system.
These screws they’re, called axial loaded screw fixings, and it’s more common for mass timber construction. The idea is that you alternate angular screw fixings. The other thing that they do is form almost like a mini truss between CLT, which further stabilises and holds the batten together.
So we have a slab, we install the CLT panels, including the roof panels, and then we install the battens and fix them through. After that, we have the cladding and that’s more or less the lure from the inside to out.
 We made a game rule for this house because it kept the size of the house smaller. The other thing is, it’s also part of the strategy to simplify the form. You should design with CLT, which lets you keep detailing simple and keeps the building simple.
We fix our insulation on top of CLT panels per the wall. That differs from a conventional residential building in Australia, you don’t have the normal Bradford blanket thing above your battens. The roofers love that because they don’t have to lay a blanket around and find where the fixing points are.
We wanted to have almost a bit western, Japanese, Japanese-inspired roof detail, where the edge of the roof is very thin and very clean. Even the outriggers they’re not actually structural, they’re fixed back to the CLT. The effect that we want is not quite Japanese, but when you drive past it, you’ll probably get the impression it’s like a very simple, but well-built house.
Exterior Design / Roof Details CLT Home
Can you tell us a bit about the design idea?
The eave, as you can see it’s just a marine ply type of eave with timber outriggers. And the idea is really just to keep the edge of the roof looking quite slim and tidy and sharp.
The way we did that was a roof sheeting detail that stops on the inside face of the facade, and then we will have our downpipes running straight down. It’s our version of a simple, honest, timber house and, I think the carpenters did a great job with it.
Stairwell / Natural Light Opportunities
It’s good to have a bit of natural light coming into the stairwell. So all the bedrooms, north, are facing the street behind the camera.The way we did it was to have all the bedrooms get access to Northern light or windows with a northern orientation.
One of the really fun things I would say about designing with timber and with CLT specifically, is, that you’ll never be running out of opportunities to create little moments like this. I think so.
Creating Light Wells and Framing Views
All the windows including the skylights are fixed to CLT. We are creating a bit of a light well with vertical standoff walls of panels of CLT. And they’re just to get the plane of the glass above the roof. This is a little bit of an indulgence on our part, but the idea is you’ll be able to sit here, take a bath and just look up and out to the view. So that’d be quite a nice part of the house. Very nice.
Designing Our Own CLT Home Passive House: A Personal Build Journey
So this house is a three bedroom house, more or less about 150 square metres. Downstairs are the public realms. So we’ve got two spare bedrooms, we got a bathroom, we have a thoroughfare here, which is an entry for where the cars are going to go, and then also a more pedestrian one. And so we can essentially have landscaping on the side of the house and a garden, a little stepping stone path to the street.
A central stair, which is the solution we came up with, one to keep circulation space tighter, and also it helps draw light into the centre of the floor plate. Having the skylight above the stairwell really brings more feeling of volume when you’re entering a house.
So, always need to figure out what to do with your leftover space, right? And in our case, the stair underneath is going to be our new home for Butter, our little dog here.
And once you enter the house, we have a long service area for laundry and a massive kitchen, cause we love cooking and baking.
Underneath the stairs would be a huge, five-metre-long kitchen island, which is one of the things that we wanted for our design for this house, being a space where we’re going to spend a lot of time in, for either cooking and also eating.
We have a beautiful skylight just above the kitchen area as well, so you can always have a good source of daylight and see the night sky when it’s evening.
The living space is just a very simple open plan, so the kitchen leads to a meals, and dining area, and then the living space where we’ll put a couch, a sofa and a telly.
This little corner is a little leftover space, but we’re gonna make a sitting platform. It’s like a tea room if you go to more Asian-style houses. We love the idea of eventually having a window to look out into a mini garden on the side of the house. We also built a little joinery platform so that you can step up onto a seating area and have a cup of tea and play some chess.
We are the architects for this house, but we’re also the owners and, in this case, we’re also the builders, so we’re doing this as an owner-builder project.
It’s our first build, so we have zero experience building something ourselves. But one thing that we found was the fact that the process is simplified because we get a watertight, waterproof shell with the CLT and Windows done in a couple of weeks.
We knocked down the old house in January, got the slab down, and took us a few months. In May, we did the entire two-story structure and also all the windows installed. And then after that, we’ve just been working through all the different parts of the house, in our spare time.
We did the installation in one go and all the internal stuff framing, then the wrapping of the house and then the battening. In terms of sequencing it’s actually quite good to design and build in this way because it’s almost like one step followed by another. There’s very little crossover between trades. Usually, we have one trade, they come and go, and then everything is neat and tidy in that way.
We’re standing in what is our master suite. It’s a little bit indulgent, but the entire level is one big bedroom with a walk-in wardrobe and en suite. Because we’re building a warm roof, which is insulation on the outside structure, we’re going to express the gable as a cathedral ceiling. The conduits and the routes in the CLT are going to be for a LED lighting strip or a ceiling fan. The idea is to get a really beautiful volume inside while keeping the bulk of the house smaller on the outside.
Inside a CLT Home Passive House Redefining Sustainable Living | Milli Studios Lalor Park Passive House
Embracing CLT and Passive House Standards: A Journey into Sustainable Home Design
 Like about a year of working on the approvals of the CDC for this property. We went through a few options about how to build it in terms of things like brick or rammed earth for one thing because we got quite interested in these low embodied carbon materials.
We decided to land on CLT because It gave us a way to design a building, which was very tactile and quite beautiful to look at. We love working with timber. There are advantages with using one system, for instance, we went through options saying, well, what if we did this space in rammed earth, but the rest of the house in CLT.
We discarded that because the interface between the two systems would have made it a bit more difficult to achieve the passive house standard that we wanted. This project became our first CLT passive house project and our first architectural project. And we worked very closely with the CLT supply installer.
In this case, it was a company called KLH, which is based in Toronto, Europe, but they also do a lot of projects in Australia and around the world. They were a very key part of this because working directly with the fabricators for the house meant that every panel and every penetration that you see, was designed and drawn by us, and then processed and coordinated with KLH. The panels were then made in their facility in Austria and shipped over to Australia, then craned into place and assembled to what you can see here. This way of working, I think that’s driving a lot of the work that we now do with Millie in that almost all of our projects now are targeting past our standards because we have a proof of concept that we bring our clients to. Once they see it and they get it, that’s what they go for. Also working in this way helps us simplify the process for our clients because we’re not trying to work out different details for different systems and different things. The clients that we work with, have quite a defined brief in terms of they want a comfortable, sustainable house, they want it to be built simply. The lessons that we learned with this project have really guided a lot of the work that we do now.
Winnie and I both come from a commercial architecture background. So we’ve worked in fairly medium to large practices in the past. We bought this old house about two years ago and as part of that, we decided to start a little practice.
Our first project was this house and we decided to do this house as a passive house after looking at what the best way is to design and build something in a sustainable way. That’s also something that we can do.
Designing Practical, Affordable Homes for Young Families: Lessons Learned from CLT Home Passive House Standards
What we’re really learning about this project as a professional couple and a young Australian couple is what house is suitable for our lifestyle, and that’s the lesson that we take away. And that’s what’s really resonating with some of the clients because at the moment, most of our clients are quite similar to us.
So they’re young professionals, they have a young family, they have an older house that they’re looking to knock down and rebuild. And I don’t think at the moment we’re, erving the quote, unquote, luxury housing market. That’s an accident too, because despite the design thinking and the work that’s gone into this house, this house is actually meant to be quite a simple and humble house.
It’s 150 square metres and, material-wise, it’s not going to be extra extravagant. The clients that we’re working with on their projects, they’re after the same thing, something that’s not going to cost them an arm and a leg. It’s going to be built well and by necessity, that means that they also have to be designed quite simply.
We’re not afraid to say that we’ve considered different things for this project, the cladding and, some of the detailing, and we’ve decided to deliberately simplify it , to make it cheaper and it’s only then we’re able to spend more of our budget on a high-quality structure and high quality windows. And I think that’s the direction that we’re heading in at the moment for our current clients. Not to say that’s what we want to do forever, but their projects, they’re really similar to us.
But for us, I think Passive House was the choice because we realised that we actually can’t control a lot of the sites that we have and the orientation in some cases for properties. And that is quite similar to some of the sites that we’re working with.
There’s just no practical way of getting that perfect north, east and northwest orientation for spaces. So I think in that sense, building with passive house standards just lets us make the best use of those particular sites. And that’s not to say that we can’t use other strategies like passive solar because, as mentioned before, we have very nice northern lights for a lot of our rooms and we’re very proactively using natural ventilation wherever we can. I think the baseline of having a well-built passive house structure means that in the very worst cases, we know that we’re going to get a very comfortable house to live in.
Prefabricated Home Redefines Modern Sustainable Living | Milli Studios CLT Lalor Park Passive House
CLT Home / Prefabrication: A Solution for the Housing Crisis and the Future of Construction
My personal feeling about prefabrication is that it is probably going to be one of the solutions for the quote unquote housing crisis that we’re going through. And I think it’s also, generally speaking, a natural, and logical way for construction to develop into.
And I think part of that is also a long term trend, materials are getting more expensive and labour’s getting more expensive. And I don’t think that’s ever going to go backwards. It’s part of what living in a developed country means.
I think prefabrication provides a way for at least part of the construction industry to streamline the product and by streamline, I also mean in terms of the program and in terms of quality but also the other one is it, gives more certainty.
So the thing about prefabrication is you move what is traditionally done on-site, which is an uncontrolled environment. So if it rains, you can’t work. But with prefabrication, whether it rains or shines, you can, because you’re making parts of a structure inside a controlled environment.
You take that part of the uncertainty out of the process. There are its own inherent problems and it’s a different set of problems that you need to find solutions for. For instance, the supply chain is something that I can be very frank about and say we did have some issues with just getting a shipment of materials from Europe . We were delayed in this case because of what’s happening in international waters, but that happens to everything that’s made globally and we were able to work around that.
Where I see this fitting in the Australian context is if, we are really aiming for more densification, if we’re aiming to build more houses than we have ever built before in, the history of Australia.
I think prefabrication probably needs to be part of the solution because there’s just no way of getting enough workers to every possible site that you can think of where houses need to be built. And I don’t think it’s feasible to do it at scale. So at the moment, prefabrication in construction is about 3%.
I’ve read studies where this will probably double in the next couple of years because you are able to take parts of the construction process offsite. And also you can dovetail and overlap parts of the program. You can do site work at the same time as your manufacturing windows and structural systems.
Refining Sequencing and Design Processes for Prefabrication Projects
 So, what we learned from this project is really, just, like a macro understanding of sequencing and a lot of little different steps with Designing for and building this project. So for instance, I think the layout, the materials the detailing and whatnot for different projects might vary. And of course, things like where sites are located might vary but the lessons learned that we are actually currently applying to different sites and different projects and different clients is Just how to sequence and how to manage and coordinate a project of this scale and this nature. And I think that’s going to be something that we will definitely be refining as we go, and developing more capacity for, and hopefully getting better and better.
There’s a saying I really like, don’t try to reinvent the wheel. With every new thing you do. So I think we really want to take that to heart with these projects that we do for all kinds. We don’t have to reinvent the wheel. With develop up our detailing and our design and our processes with every project that we do, which involves, passive house, which involves prefabrication.
And I think the end goal for that is really just to, make it more, make the design more refined, make the product more refined, and also hopefully make it more economical in the long run.
