In Budapest, on the boundary of the Orczy and Magdolna quarters, the residential block enclosed by Kálvária, Dugonics, Kőris and Diószeghy Sámuel Streets presents a very mixed picture. New residential properties sit next to 100–200-year-old buildings ripe for demolition and missing-tooth plots, just a short walk from the Ludovika complex, the Botanical Garden and Semmelweis University’s clinics. These factors made the area suitable to host Semmelweis University’s ambitious Science Park project, which showcases forward-looking solutions in concept, function and technology alike. We spoke with Gábor Vörös, lead designer at CÉH zRt., who—together with a 20–30-member project team—worked on the design won through a public procurement procedure, under the leadership of project lead architect and principal designer Ferenc Balogh, over the past almost four years.

What client intent led to selecting the block along Dugonics Street?

V.G.: Semmelweis University’s goal is to rank among the world’s top 100 universities within a foreseeable timeframe. Beyond educational facilities, this requires a scientific center suitable for research—just as is customary at leading universities like Oxford, Cambridge, Delft or MIT. The planned building complex answers this need. Since it must be geographically as close as possible to other university blocks—also because of the “overlap” between clinical and research activities—the 8th District block in need of renewal was an obvious choice.

According to the plans, the complex—comprising four buildings and three underground levels extending beneath the entire site—will primarily house biotechnology laboratories, while also accommodating associated offices, postgraduate education, a library, lecture halls and various community spaces. To illustrate the functional complexity: the layout was developed with input from the heads of 27 university institutes. The two taller buildings have six floors above ground, the lower ones have four; altogether the net usable area is roughly 60,000 m², with three contiguous basement levels below grade. The ground floor is continuous across the buildings; its slab forms a connected roof garden with several openings and is accessible from the street. This met a key district requirement: the new green space and part of the facility should also offer recreational areas and services for local residents. The University likewise intends to provide the surrounding schools and residents with an accessible window into health-care research.


What are the project’s most distinctive or forward-looking solutions?

V.G.: It goes without saying that the entire complex will be highly energy-efficient: air-to-water heat pumps will meet demand, and ventilation will use heat recovery—now thankfully not uncommon. Beyond this, the building incorporates new, bespoke solutions. During construction we may also pursue a green certification; the design has been developed to align with such requirements.

If I’m not mistaken, we can start at the roof.

Yes. Green roofs are still not ubiquitous, but we designed the Science Park with a so-called blue roof. Here the roof surfaces not only support vegetation; the rainfall is also retained and used on the roof instead of being drained immediately into the sewer—only to be, figuratively speaking, “bought back” for irrigation. The practice of blue-roof concepts is still evolving globally, but proven technologies do exist; we chose one of these. Our initial idea was to use an Austrian system with a strong track record, allowing significant water storage beneath the green roof layer, separated from the slab—which is structurally sized for this load. A leak-detection system would have monitored the tank’s integrity and, in case of leakage, automatically drained the stored water to the rainwater system and flagged the segment requiring repair. Implemented in its original form, this was not possible due to current Hungarian regulations that require a 2–2.5% slope even on flat roofs. As a compromise, we selected the deepest-profiled drainage sheet available; the ribs still retain a substantial volume of water. This is less than initially planned, but the vast majority of rainfall will still be usefully retained. Below this layer lies the waterproofing; above it, extensive or intensive green roof planting will use the stored rainwater.

Still on the roof: combining PV panels and green roofs is also unusual, and here they will co-exist on the same surfaces. Vegetation will extend under the tilted PV modules, whose lower edges will be 30 cm above the roof. The technology—known as Greensolar—was originally designed for ballasted placement, but wind simulations (more on those later) led us to choose mechanical fixing, using an aluminum support structure with as few “feet” as possible to minimize waterproofing penetrations. The supports are anchored to the slab, thus passing through the green roof build-up, planting layer and water-retention zone.

What innovations do we find beneath the roof?

V.G.: Less common still is the extent of simulation we integrated. Orientation and solar access matter for PV, of course, but we carried out comprehensive daylight simulations for the entire complex, modeling the built and natural context. We used the results to calibrate the ratio of glazed areas to green façades. The same simulations were crucial for the internal park, helping us select plant species suited to the prevailing light conditions.

We also analyzed wind patterns and potential wind corridors for PV fixing, since air movement on the 6th-floor roof can be significant and must be considered when sizing the supports. In this context we applied Eurocode structural design and determined wind suction and pressure zones.

We simulated noise exposure as well, which affected the allocation of offices and laboratories. Interestingly, this produced the opposite tendency to daylighting: due to narrow streets the lower levels receive less daylight, which would suggest larger glazed areas; however, noise simulations showed the lower levels to be louder, arguing for reduced glazing. We ultimately prioritized better daylight, while upgrading acoustic performance for the glazing.

An equally innovative and labor-intensive effort extended the “thermal-bridge-free” requirement on façades to include fasteners penetrating the insulation and to inverted flat roofs as well. This followed from the overall design ethos and client expectations, and is now also mandated by a new Ministry (ÉKM) decree—even if not yet universally embedded in design practice. Meeting this required numerous thermal-bridge simulations and the creative use of suitable fixings and spacers, including brackets with thermal-break isolators—without compromising mechanical properties or fire safety.

How should we imagine the green façades?

A bit differently. For one, they will be green from day one—no need to wait years for growth. Plants will climb a cable-mesh support system, enabling pre-grown modules to be installed. The system also allows “endless” living walls and affords great freedom in species selection: we can incorporate flowering species for seasonal effect, and—thanks to the daylight simulations—place each plant in optimal light. Importantly, we can use deciduous species that provide shading in summer while admitting winter sun to the same areas.

The planters for the green façades are placed between the mesh and the façade, where a 60 cm offset is required; from the outside they will be essentially invisible. An automated irrigation, drainage and fertigation system complements the concept and can be programmed to the differing needs of each species. Together, these elements allow us to design the plant walls in a checkerboard pattern alternating with glazed areas. The design principle for the office façades was that every room behind the façade should also have a window area without a green screen; hence the checkerboard, which also creates a distinctive architectural expression. Beyond shading, the plant walls also contribute modestly to noise attenuation.

Taken together, we hope this will yield a project that may be considered exceptional in Hungary, both for its complexity and its research function. The complex, developed in close collaboration with Semmelweis University’s excellent experts and scientists, will be worthy of the university’s ambitions. The plans are complete, and as designers we very much look forward to smelling fresh paint in spaces we have already traversed a hundred times—virtually.

This post is based on our article published in Octogon Labor.