Sustainable and speedy: Prex Co. achieves construction goals with support from Leica iCON solutions

Headquartered in Kobe, Japan,Prex Co.，Ltd.(Prex) is dedicated to low cost, short duration construction and environmentally friendly housing. As part of this mission, the company developed a unique precast foundation that has reduced foundation installation to just two hours.

TheLeica iCR70robotic total andLeica iCON buildsoftware for construction are integral components in Prex’s high-precision, fast installation of the precast foundation. This total solution enables Prex to achieve an extra short construction period – with only three days from the start of construction to topping out of the building and total projects completed in less than 30 days.

奉献创新，可持续住房

Prex is dedicated to attaining sustainable development goals, including offering zero-emission houses that reduce CO2 emissions to zero over the home’s life cycle, minimal houses that are compact and inexpensive and even off-grid housing that combines solar power generation and storage batteries for self-sufficient electricity. Prex’s methods are rooted in finding innovative ways to solve current challenges. For example, Japan's population has been declining for several years and, along with it, the working-age population. This has resulted in labour shortages for the construction industry. At the same time, Prex sees the need to develop more accessible and sustainable housing, helping people experience an increased standard of living, especially families. To address both these issues at once, Prex developed and now deploys precast foundations, which can be constructed in a short period of time with fewer workers at a low cost.

The precast foundation installation only takes two hours. Prex workers use a Leica iCON iCR70 robotic total station, which supports an easy one-person operation, for layout.

Precast foundations installed in just two hours

Prex的预制基金会彻底改变了施工过程。

Prex的主席Shogo Arai解释说：“到目前为止，为房屋建立基础，需要工匠的技能，用于土方工人，钢筋和模板阶段，建筑期花费了大约两个星期。”“但是，借助我们最初开发的预制基础，它可以在短短两个小时内就安装，而无需现场专家。”

该公司于2019年开发的预制基础是在工厂制造的，具有高强度和质量，以毫米精度制造。结果，预制基础的寿命约为150年，可以反复使用。

建筑的大约70个汉堡are meters, the foundation work can be completed simply by installing the precast foundation at the four corners of the building and then stacking the factory-produced housing materials.

Before: Conventional on-site casting foundation method. This method requires many construction workers and about two weeks to assemble the formwork and reinforcing steel and to place the fresh concrete.

之后：对于约70平方米的建筑物，预制基础方法仅需大约两个小时即可在四个角落安装基础块。

High accuracy and easy operation with a robotic total station

Since there is almost no need to cut and adjust the length of components on site, it is important that all layout accurately meets the design tolerances to ensure a perfect fit. For this reason, Prex carefully selected the construction equipment used for marking out sites. “The position of the precast foundation and the bolts installed in the foundation effect the accuracy of the entire house, so high accuracy within a tolerance of 1 millimetre is often required," says Arai. To achieve this high accuracy, Prex chose the Leica iCON iCR70 robotic total station with iCON build software – both designed especially for construction.

“We tested and compared many different types of total stations," reflects Arai on Prex’s decision to invest in the iCR70. “The iCR70 is very accurate, and even when a vehicle or worker crosses the road during the layout process and the total station loses sight of the prism, it recovers quickly. Our working environment is very dynamic and therefore we had to evaluate the ability of the total station to quickly recover from possible line-of-sight interruptions, keeping downtime to a minimum. We are very pleased with the performance of the iCR70 in this regard.”

“我们还选择了ICR70，因为它可以在有或没有棱镜的情况下使用。当我们需要1毫米级的准确性时，我们可以使用棱镜，并在难以使用棱镜的情况下继续使用非反射目标有效地工作。”for marking out coordinates, they can be used according to the scale and purpose of the site. Importantly for Prex’s goal of fast and inexpensive construction, the iCR70 also allows a single person to perform layout work, increasing layout productivity by up to 80%. “Before, we used to measure the distance between precast foundations with a measuring tape and check the height with a level, which required two or three workers to layout. However, with the iCR70, we only need one person to do the layout," Arai continues.

Smooth guidance with construction-tailored software

In combination with the iCON total station, Prex uses Leica iCON build construction software on theLeica iCON CC80控制器平板电脑数字化和简化布局过程。使用AutoCAD创建并以DXF格式保存的建筑物的3D模型，第一步是加载DXF文件，并将要在运行ICON构建的字段控制器构建中列出。

The screen then displays a 3D model of the foundation and other parts of the building, the points to be laid out and the current position. iCON build provides easy-to-follow navigation to the desired point, so anyone can reach points quickly without making mistakes. Additionally, with the CC80’s 7-inch touchscreen, Prex crews can easily see the layout points and navigation even in direct sunlight. With clear visuals and intuitive features, one-person layout is easily and quickly completed, allowing the rest of the installation process to proceed.

Layout points and current position on the 3D model in Leica iCON build. The software provides easy-to-follow navigation in terms of direction and distance to the target point.

如今，由于Leica Geosystems Icon Construction Solutions的技术，Prex正在将其可持续性的业务目标和更好的明天变成现实，从而验证了他们的公司哲学和使命。