1000+ Passive House Apartments in Spain

View the chat transcript.

Clara Lorente:

Okay, so good afternoon, first of all. Thank you for having us here today. We are Clara and Angel, and well, we are from Spain. Anna has introduced us already. Today, we will talk about several topics. First of all, we will briefly explore how Group Lobe works as a company. Then we will talk about how we have tackled certain challenges, achieving Passivhaus quality of buildings, summer performance, and user experience. Then, we will also talk about a challenge that we are trying to solve right now. That is lowering our carbon footprint.

Clara Lorente:

Group Lobe is a construction company with 30 years experience, that has evolved to be more efficient. It has incorporated new professionals, with various qualifications, in order to aggregate all the real estate process under the same roof. We cooperate through B.I.M. Tools, such as hube, our self-developed software, that allows all the agents to work on each project in a collaborative way. And from the beginning to the end, the decision making follows different criteria, the design commercial, energy efficiency, and so on, with a common goal of offering the best possible homes.

Clara Lorente:

Since 2018, Lobe builds only multifamily residential buildings that are Passivhaus certified. They're located in three regions, in Zaragoza, Madrid, and Valencia. Right now we have 19 Passivhaus certified multi multifamily residential buildings, which make 1,200 units. We recently certified another one this Monday. So, it's now more than 1,000. And 50% of that is social housing, which means that they are becoming more and more available in the Spanish market at an affordable price. Here, you can see several projects that are already certified, under construction, or being designed right now, and well, since they are multifamily residential buildings, each one has a lot of surface area. And this means that our 19 certified buildings make around 70% of all paid certified area in Spain. Now I will talk about how we are going to achieve Passivhaus quality.

Clara Lorente:

One of the first challenges we faced was the thermal enclosure progress. At the beginning, we had to increase the thickness of the insulation layer. So that meant they would become wider. In Spain, the urban regulations limit the amount of build surface you can build in each float of land. So, that means that if your walls are really thick, you're compromising the actual size of each home. We call this surface efficiency ratio and that means that the design is better. The more usable area you have, and the less gross floor area you occupy.

Clara Lorente:

So, here we have a floor plan and a photo of the first multifamily residential that we built Passivhaus. And as you can see, the walls were really thick in comparison to the division between rooms. This is the section, the first one was a section of that building. As you can see, it was pretty thick. It was like 45 centimeters thick. Basically, it was a result of adding 12 centimeters of insulation on a masonry wall that like traditional one. And since then, we have been developing different wall sections in order to achieve the same hydrothermal performance in a more spatially efficient way.

Clara Lorente:

Now, Angel.

Angel Sanchez:

Hi everybody. I'm talking to you about our progress in tightness. On the left, we have a typical detailed section of one of our buildings with thermal graphic diagrams for each thermal bridge. And on the right, you see three details about a tightness solution. In fact, all of them are following the same principles. We solve vertical tightness in red with prefabricated insulation panels while [inaudible 00:05:01] tightness is solved taking advantage of the concrete structure in blue. So this way we create an individual enclosure for every apartment, which is very useful for us because we have an individual mechanical ventilation with heat recovery. At the very beginning, we used to seal every joint with liquid membrane, vertical joints between panels, structure and installations, and so on. While windows were sealed with pre compressed tape and foam. I'd love to show you a very interesting detail on the top, right picture.

Angel Sanchez:

We plan all installations pieces, and prepare block of installation with holes in them so we can seal every pipe one by one. After many projects, we decided to improve our solution, making it easier, cleaner, and faster. And I honestly think it was a great idea. Now we seal everything with air tightness tapes, except installation and other system uses. While we seal windows only with pre compress tape, with [inaudible 00:06:05] real layers. And it was worth it, in my opinion, it's working quite well. On the right bottom picture, we have a typical apartment with zero point 15 renovation per hour.

Angel Sanchez:

All this progress means to get better in terms of quality, but also to get faster testing. By this, we can feed into production schedule, not delaying critical tasks. We have our own blower equipment, five in total, and we test every apartment individually at least two times. First test ensures the air tightness is okay. This way we can figure out possible mistakes for missing points. And we can ensure that Passivhaus standards will be met. And then we do another final test with an external server as an auditor, in order to guarantee our clients the fairness of results. In columns, and on the left, we have hours spent per apartments while the line express final blower door value for each project. These are the projects located in Madrid. This means that we have been reducing our testing while we got better results. You can make an idea about the significance of spending half of the time that we spent two years ago. It's also remarkable that we came from 0.6 renovation per hour to 0.35 we are now.

Angel Sanchez:

And just to give you a brief comment about how we try to improve building processes, I think you would like to know Lobe's workflow. At the same time, we designed a building and its production process, in a lean project delivery system. We work together, divided in groups, into the same B.I.M. model. Lobe has created his own software based in a construction 4.0 philosophy, call it hube. Images on right, are capsules made for every month that shows the progress on construction sites. Site managers have follow-up meetings weekly, where they can discuss their projects while they are seeing the real thing, the real building I'm in. By the way, we have cameras installed in every building. So it's just like a construction [inaudible 00:08:24].

Clara Lorente:

Here in this slide, we can see the result of all this process. We built isometric building a few years ago. The first phase met the national building code, and the other phase was Passivhaus. Each phase has 63 units. In terms of materials of components, going for Passivhaus meant an increase of 3000 Euro per unit. But improving construction services and using industrialized solutions meant that we managed to reduce around 1000 Euro per unit in terms of construction services. That way, the total construction increase cost in the second phase, in the Passivhaus one, was only 2% more.

Clara Lorente:

And now I will talk about another challenge, summer performance. In Zaragoza, and Madrid, and Valencia, we have climates similar to California. So cooling is our main energy demand. Here we have an example of an energy consumption of an apartment during 2021 that we are currently monitoring. As you can see, they have only consumed domestic hot water, that is pictured in orange, and cooling, that is pictured in blue. The apartment is in Zaragoza and has good orientation, and it's running by neighbors. And here you can see where it's located for you to picture better the location.

Clara Lorente:

This example does not mean that we never have heating demand, but I think it shows how, more or less, it works. So, shading, it's really important. So we need to think about overhangs, terraces, and roller blinds to essentially avoid overheating. We have developed some details in order to limit the thermal bridges that appear when building terraces. Here you can see we include high resistant elements embedded in the floor slabs. The blocks are located around the perimeter of the thermal enclosure in each home. Our goal is that terraces keep shaded the facade walls during the hottest times of the year.

Clara Lorente:

This is a picture of Arcus, a whole block with 171 units that we have recently certified in Zaragoza. The photo was taken of June 2021 and all the facades were shaded at the midday. Shading also reduces a lot the amount of solar radiation that is absorbed by the walls. And, therefore, means that there can be like 50% less cooling demand as a result.

Clara Lorente:

Exterior shading of the windows is also important to limit solar gains in the hot months. But the fact that could be removed is useful in winter to reduce heating demand. So, in Spain, roller blinds are common. They provide not only light control, but also safety, and privacy. However, traditional roller blinds have two handicaps. They are a huge thermal rates, and they're not air tight. So we've been working with various local manufacturers in order to improve the products that were available in Spanish market. And we have redesigned insulation, and joint, in order to make them airtight and reduce thermal bridges.

Clara Lorente:

Here, you can see a data sheet, and lab essay, of one of the models we have co-designed with one manufacturer. These kind of roller blinds come as a block with the rest of the window. So, they are easy to install and they come with like a half moon of insulation inside a PVC box.

Clara Lorente:

Finally, we can see an example of thermal bridge caused by roller blind. As you can see, there's still some heat loss through them, but shading is much more important in our climate.

Clara Lorente:

To end, I'm sure you can imagine that more than 1,000 units mean that more than 1,000 different families are already living in our buildings. So, this has been a challenge in terms of finding a way to easily explain how everything works, provide the support service whenever they need it, and make sure everyone thinks living in a Passivhaus home is something new, but not necessarily something difficult. So, here you can see some info, and documents, that we have developed, and we find really useful. An easy maintenance manual and videos that we produce for each building and where everything is explained.

Angel Sanchez:

Well, and last but not least at all, one of the challenges we are facing now, is how to reduce our carbon footprint? We are following European regulation to quantify it, and we are carrying out Real Building evaluation to compare the results to different improvement scenarios.

Angel Sanchez:

In first case, in blue, we adjust the building to compulsory energy efficiency regulations, just changing the thermal enclosure. And in the other case, in orange, we propose a cross laminated timber structure instead of the reinforced concrete we have. We generate lists of elements through us build hube project and our energy simulations, and associate their impacts from reliable databases. Since we know our carbon footprint, or global warming potential per systems, we can compare different alternatives. Comparing with regular buildings, let us know how much contribute industrialization and Passivhaus, why we are going to study new opportunities and scope of improvement with new solutions. And I think that's all. Thank you for your attention. Thank to this wonderful platform for having us here today. And I hope you found it interesting.

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