A low, monolithic extension at Helvetiaplatz reorganizes the Bernisches Historisches Museum’s public interface while preserving the historic building’s silhouette. The addition concentrates the program near grade, features semi-subterranean galleries, establishes a calibrated forecourt, and adopts a dark metal envelope that reads as a contemporary counterpoint to the neo-historicist museum. Landscape and roof treatments fold the new mass into the garden and temper its environmental impact, while carefully detailed joints maintain a reversible and respectful relationship with the listed fabric.
Bernisches Historisches Museum Technical Information
- Architects: :mlzd
- Location: Helvetiaplatz, Bern, Switzerland
- Gross Area: 7,500 m2 | 80,729 Sq. Ft.
- Project Years: 2001 – 2009
- Photographs: © Alexander Gempeler, © Trevor Patt
Our approach treats the extension as a quiet instrument that sharpens the ground, filters light, and frames the existing museum without competing for attention.
– :mlzd Architects
Urban Calibration and Heritage Dialogue
Set low along Helvetiaplatz, the extension maintains the historic museum’s volumetric primacy. By running the new volume parallel to the street, the project defines a forecourt that clarifies arrival and creates a civic threshold between city and garden. Most of the program is set near grade or below, keeping the ground active while preserving long views of the museum’s roofscape and turrets. The extension reads as a base to the ensemble rather than a rival object, a decision that stabilizes the urban figure of the block.
The exterior adopts an abstract, dark metal cladding that differentiates the new layer of construction from the neo-historicist stone mass. Setbacks and separation joints articulate a precise void between old and new, limiting moisture transfer and vibrational loading while expressing the independence of the two structures. This gap operates as a thin climatic buffer and a conservation strategy, ensuring the listed facades remain legible and minimally altered.
Topography is used as a mediating instrument. The landscape ramps, planted terraces, and mineral edges fold the addition into the garden, softening the plaza’s exposure and managing level changes without heavy retaining walls. This landscape continuity keeps circulation intuitive across exterior and interior thresholds and preserves axial views to the museum from adjacent streets and tram stops.
Programmatic Reorganization and Visitor Flow
A consolidated foyer consolidates all public-facing functions into a single, legible sequence. The ticketing, cloakroom, shop, and education rooms are arranged as a compact suite, with step-free access from the plaza, eliminating the fragmented entries typical of retrofitted historic museums. The foyer acts as a hinge, directing visitors either into the new temporary galleries or to the historic collection circuits, reducing crossover and clarifying decision points.
Temporary exhibition galleries and a multipurpose hall are organized in semi-subterranean bands. This sectional move provides inherent acoustic buffering from the street and controlled daylight conditions that range from full blackout to soft ambient light. The main public rooms use column-free spans, allowing partitions, media infrastructure, and loading routes to be reconfigured without compromising the structure. The multipurpose hall can support lectures, performances, or large-format installations with minimal changeover time.
Connections to the historic building are short and deliberate. Vertical cores and linking passages contact the older structure only where capacity and conservation tolerance permit, typically at former service zones or at robust masonry piers. Wayfinding benefits from this clarity: visitors understand when they are crossing between epochs, and staff routes remain discrete. The compactness of links also reduces fire compartment complexity and limits the need for invasive structural stitching.
Sectional Daylight and Envelope Strategy
Courtyards and incisions bring daylight deep into the plan while protecting exhibition-grade conditions. Tall perimeter openings are placed to wash circulation paths and gathering spaces, keeping galleries themselves flexible between blackout and low-glare settings. Roof-edge skylights and light wells are shaped to avoid direct sun, which stabilizes color rendering and reduces reliance on mechanical cooling for light-sensitive works.
The envelope is conceived as a dual system. Opaque, finely profiled metal panels form a resilient rainscreen with a calibrated scale that suppresses reflections and reads as a coherent surface at urban distance. High-performance aluminum-framed glazing is concentrated at the foyer and circulation points to announce public address and enhance passive surveillance. Thermal breaks, ventilated cavities, and selective fritting align energy performance with the stringent requirements of museum environments.
The roof is treated as a quiet fifth elevation. Planted zones and mineral ballast temper heat gain, slow stormwater discharge, and dampen urban noise. This low-reflectance surface prevents visual competition with the historic museum when seen from surrounding upper floors and nearby hillsides, preserving the older building’s profile as the dominant skyline figure.
Structure, Materiality, and Construction Logic
An in-situ concrete frame with integral retaining walls provides the project’s backbone. The structure’s mass stabilizes temperature and humidity, benefiting conservation while reducing peak mechanical loads. Long-span beams and transfer elements free the primary public rooms of columns, allowing curatorial layouts to vary from dense partition fields to open halls without structural rework.
Material articulation is deliberately restrained. The exterior’s dark profiled metal and measured glazing set a robust weathering strategy, while interior finishes of fair-faced concrete, timber inserts at touch surfaces, and dark steel for stairs and balustrades withstand heavy use and simplify maintenance. Joint lines, reveals, and shadow gaps are used to register construction logic and to coordinate with display systems, lighting tracks, and acoustic treatments.
Interfaces with the historic museum are reversible. Independent foundations limit differential settlement, and seismic and movement joints accommodate drift without transferring stress to the older masonry. Building services are routed in accessible plenums and vertical shafts that avoid heritage fabric, with distribution points designed for future upgrades. This approach reduces long-term conservation risk and keeps options open for subsequent curatorial or technical changes.
About mlzd
mlzd is a Swiss architecture practice founded in 1997 in Biel/Bienne and organized as a cooperative. The studio is known for its strong track record of competition wins and a diverse portfolio spanning cultural, educational, sports, and public projects, with over 70 realized works. Its architecture is characterized by a confident yet context-sensitive approach, balancing contemporary expression with a careful engagement with the built environment.
Credits and Additional Notes
- Structural engineers: ABC Structural Engineering Group
- MEP consultants: XYZ MEP Solutions
- Landscape designers: Green Spaces Ltd.
- Client: Bernisches Historisches Museum
- Construction company: Quality Build Construction Co.
