BIM-to-field during the new construction of the Aarau cantonal hospital
BIM-to-field during the new construction of the Aarau cantonal hospital

BIM-to-field during the new construction of the Aarau cantonal hospital

The new construction of the “Dreiklang” hospital project in Aarau is in full swing. The work on the inner lining will require a total of roughly 18 months. Marti is working completely digitally on this large construction site using the BIM-to-field method.

They currently dominate the cityscape of Aarau – a total of eight cranes stand in a perfect arrange­ment around the large con­struc­tion site in the middle of the hospital grounds. Work on the inner lining of the new Aarau Cantonal Hospital (KSA) is forging ahead. In 2021, the initial pre­para­tions com­menced at the con­struc­tion site, and Marti Zurich also carried out the first special civil engineering tasks from the sum­mer of the same year. The building con­struc­tion depart­ment has now been working tirelessly on the inner lining of the building since January 2022­.­­

The New Aarau Cantonal Hospital Building Is a “Dreiklang” (triad)

In the spring of 2019, the new “Dreiklang” (Triad) building project was selected by a competition jury as the winner of the overall per­formance competition. The building concept is focused on integrating functionality and short distances for both staff and patients. The planned total floor area of approx. 110,000 m² will ac­com­modate 472 inpatient beds, 130 day-clinic places, and 21 operating rooms. The new building is divided into three main areas: out­patient clinics, functional areas, and the wards. Despite this structure, the areas will form a single unit in the overall building. Once the new building is completed, the existing buildings will be de­molished and the park, which forms part of the hospital complex, will be re­de­signed. This increases the dimen­sions of the largest green area right in the heart of the city from 75,000 to 94,000 m².

“The teamwork here is spec­tac­ular. If a special chal­lenge presents itself at the con­struc­tion site, every­one works to­gether to solve the problem.”
Toni Würsch,

The Digital Inner Lining

The entire inner lining is con­struc­ted in the BIM-to-field model, without any paper plans at all. The various planned houses are digitized and the em­ploy­ees on the con­struc­tion site are all equipped with tablets. This makes it possible to access all in­for­mation directly in the BIM model. This is one of the largest BIM projects to date.

The geo­metrical changes to the new building proved a particular challenge in terms of structural engineering. After all, the building is not just a square block. The floor plans have already under­gone steady changes in the three base­ment levels until the complete building size of approx. 120 × 145 m was reached on the first floor. It remains at these dimen­sions up to the 3rd floor (base building) and then moves back for the ward block (up to the 9th floor). We selected a slightly different staging approach based on these special conditions. Instead of starting in a corner, the inner lining of the building is built from the center out­wards. This is due to the fact that the highest building height of 50 m must be reached in the middle at the end.

Due to the massive dimen­sions and complex planning, the entire inner lining is divided into four sections, each of which functions as its own con­struc­tion site. With a pre-developed ingenious matrix, the basic tasks of the fore­men for these sections are defined spe­cifically for this purpose. And yet the entire team works hand in hand. 120 to 140 em­ploy­ees are on duty during the intensive con­struc­tion phase.

the stakeholders include