Eller + Eller Wraps a Düsseldorf Office Campus for WPP in Germany's Largest Closed-Cavity Facade

MIZAL sits on a corner plot at Völklinger Straße and Plockstraße, the point where one of Düsseldorf's busiest arterial roads meets the entrance to the Medienhafen. Designed by Eller + Eller Architekten GmbH for developer CODIC and anchor tenant WPP Deutschland, the campus holds roughly 2,500 workplaces across 52,000 m² of usable floor area. Its parts rise to 11 storeys on the street side and step down toward the harbour to the west. It earned DGNB Gold certification and the BDA Architekturpreis Düsseldorf 2023.

The headline is technical: MIZAL carries the largest closed-cavity facade in Germany, supplied by Josef Gartner. But the facade is not the most interesting thing about the building. What makes it worth your attention is how Eller + Eller use that sealed, rounded skin to do two opposite jobs at once. Along the traffic it acts as a shield. Behind it, the plan opens into courtyards, atria and roof meadows. The project is a lesson in using a hard edge to buy a soft interior.

A Long Bar That Shelters Everything Behind It

The 11-storey block along Völklinger Straße works as a barrier. It takes the noise and exposure of the arterial road so the lower buildings behind it do not have to. On the south side, projections and recesses break up what could have been a relentless linear front. On the north side, the massing loosens into a more open arrangement of volumes and courtyards.

The corner does real urban work. Coming from the south, it closes the view down Völklinger Straße, then turns and carries that gesture into Plockstraße. Many office campuses on arterial sites treat the corner as leftover. Here it marks the point where the city changes character, from traffic corridor to harbour district.

The Closed-Cavity Skin

A closed-cavity facade seals the gap between its inner and outer glazing, typically feeding it with dry, filtered air so the cavity, and the blinds inside it, stay clean. That is why Eller + Eller can describe the envelope as maintenance-free. On a site beside heavy traffic, the logic is obvious: you get double-skin acoustic and thermal performance without the cleaning regime that open-cavity systems require.

Architecturally, the team pushes the system further than most buildings with this technology. The elements run in continuous horizontal bands and turn the corners with rounded profiles. White fins and angled panes give the surface a ribbed, undulating rhythm that reads differently as you move around it. Integrated ventilation elements sit within the bands, so the building can breathe without punching extra openings through the skin. The result is technically sophisticated, though the continuous banding also flattens out any sense of what happens inside.

A Comb That Turns the Back Into a Boulevard

The most intelligent move on the ground is the comb-like building line. Instead of drawing a hard boundary between private campus and public street, the footprint interlocks with the surrounding space. What would normally be the building's back becomes a boulevard, lined with planting beds, maple trees and a covered walkway carried on slim grey fin columns.

The courtyards between the curved glass volumes carry the same idea further. Wooden planter benches and young trees sit under covered passages, so the outdoor space reads as a shared room rather than a gap between buildings. Whether these spaces stay truly porous to the public, or quietly become corporate territory, will depend on how the operator manages them.

Roofs Treated as Workplace Landscape

A dedicated meeting floor opens onto large roof gardens. This is where the stepped massing pays off. Because the building parts drop in height toward the Medienhafen, each lower roof becomes a terrace overlooked by the tower behind it. The planting avoids a manicured corporate lawn: yellow flowering perennials and grasses, closer to a meadow, with concrete benches set directly into the beds.

We think this is the strongest argument for the project's "New Work" ambitions. Open-plan floors and breakout sofas are now standard. Giving staff a real outdoor landscape at height, attached to the floor where meetings happen, is a more meaningful change to how a working day can feel.

Pavilions, Voids and Sedum

Small rooftop pavilions in corrugated metal and sloped glazing sit at the end of curving paths through the planted beds. They give the roofs a destination and a scale break, so the terraces feel less like a technical surface and more like a garden with follies.

Elsewhere, sedum and grasses run up to curved railings around circular voids that drop into the courtyards below. These openings tie the roof landscape visually to the ground plane, and they reinforce the stated sustainability concept, in which extensive green roofs play a central role.

A Lobby Built From Industrial Pieces

Inside, the foyer swaps the polished minimalism of many headquarters for a tougher material palette. Board-marked concrete columns, a corrugated metal core and a slatted timber ceiling form the backdrop. The reception desk is the one sculptural object: a fluted, ribbed form wrapped around a column and topped with ring lights.

The adjoining restaurant extends the foyer into a social space instead of a pure security checkpoint. That matters in a campus for 2,500 people, where the ground floor has to function as both front door and common room.

Work Floors With Their Services on Show

On the office floors, exposed red service pipes run overhead against timber-clad walls and floor-to-ceiling glazing. Leaving the services visible is a familiar creative-agency gesture, but here it suits a tenant whose business is communication. The building shows how it works.

The window bands and asymmetrically placed loggias give each zone a different relationship to the city and the courtyards. Sliding glass doors open lounges onto balconies, which partly offsets the sealed nature of the closed-cavity envelope. The three atria do the rest, connecting the floors visually to each other and to the outside.

Plans and Drawings

The site plan and ground floor plan make the comb strategy legible: two linked building masses wrapped around courtyard voids, with landscaped edges pulling the street into the plot. The upper floor plan shows office rings around square voids joined by a central bridge deck, an efficient layout that keeps every desk close to daylight from either the facade or an atrium.

The section is the clearest drawing of the whole idea. A low, planted block sits against the tall tower, atria cut through the middle, and the fully automatic parking system occupies the basement. Placing cars underground and mechanising them frees the surface for courtyards and planting, which is what the rest of the design depends on.

Why This Project Matters

Large speculative office campuses often stop at the facade: a glossy, certified skin wrapped around a generic floor plate. MIZAL avoids that trap. Eller + Eller treat the closed-cavity facade as an urban instrument, a protective wall that makes the courtyards, boulevard and roof meadows behind it possible. The technology serves the site strategy, not the other way around.

There are trade-offs. The continuous banding can feel uniform, and a sealed, maintenance-free envelope gives occupants less direct control than a conventional operable facade. But as a model for building dense workplaces on hostile arterial sites, MIZAL is persuasive. It shows how a single hard edge can carry a district's noise and traffic so that everything behind it can be greener, slower and more open.

WPP Headquarters MIZAL by Eller + Eller Architekten GmbH. Location: Düsseldorf, Germany. Area: 52,000 m². Year: 2023. Photography: Marcel Kusch, Manos Meisen, Eller + Eller Architekten GmbH.

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