Lepoglava visitor centre

Architecture

How does one add a building to a historic architectural ensemble in a quiet and subtle way, while filling the visitors' hearts with joy

Concept

Starting points

A good public building is simultaneously a little town and a big house, i.e. it offers a variety of uses and gradual transitions between public, semi-private and private spaces, while giving all its users the feeling that, each in their own way, they belong to the space and that the space intimately belongs to them.

In order to achieve that, the building is necessarily complex, while communicating its structure and atmosphere to the user with absolute clarity.

The building of the Lepoglava Visitor Centre communicates with moderation, without excess expressiveness, striving to fit into its spatial surroundings and their historic continuity, and to allow the user to discover, layer by layer, its interior and find their own “power place” in it.

Movements

The journey begins far ahead of the building’s entrance, in the educational park to the west, which is designed to attract pedestrians and keep them moving in any one of the countless directions they can pick between the circles of medicinal herbs which are inspired by the healing tradition of the Pauline Order. The park of walking, sitting, playing and contemplating is a transition between the natural surroundings and the Complex and introduces the lace theme, i.e. fluidic interconnections, into the organisation of public spaces.

The pattern of the lace underlay has inspired the underlaying pattern of the park and the square between the Centre and the convent/church. The selected pattern is hexagonal because, unlike the triangle and the square, hexagons fill a plane in a most compact way (no straight line can be drawn so that it divides a plane of hexagons in two without cutting through hexagons). Hexagons are then moved apart to form the “full”, whereas the space between them forms the “empty” one can walk through in various directions. The hexagons are then replaced by circles in order to make the passage between them smoother, more attuned to the natural movements of man. The circles take on different sizes in order to create varied spaces in between them (for slowing down, socialising...) without decreasing the density of the pattern. The circles are thematically diversified, from medicinal herbs of the Paulines in the educational park, to grassy patches around trees, elevated areas with grass and seating, the stage on the square, the revolving-door at the entrance to the Centre, the info-desk, the gift-shop and the panoramic elevator.

There is, however, an alternative path to the square, leading not through the park but along the main, wide, representative axis ending at the facade of the church. From the axis, one can follow the main approach to the entrance of the Centre, or pass to the centre of the square with an open-air stage. However, instead of the wall that used to be, the height difference between the square and the space in front of the church and the monastery is resolved by means of wide stairs, including auditorium seating, in order to achieve visual and physical porousness, to stretch the diagonal communication between the church entrance and the Centre’s entrance, and to create a representative podium emphasising the position and importance of the monastery and the church. This composition should include the removal of trees near the monastery, while keeping the western and northern tree lines which act as porous membranes between the three zones of the square and regulate sun exposure and the microclimate.

Changes

While moving along any one of the above mentioned routes, the building of the Centre, which seems from a distance like a simple white body with a red roof, is increasingly revealed in its true nature. Every element of its appearance is actually a fusion of traditional and contemporary components, which help to blend it with its spatial and temporal environments:

Transitions

Having stepped into the building, one discovers that which was partially hidden behind the thin glazed envelope of the southern facade: within the white wooden house there is a grey stone house (multipurpose hall), so the building turns out to be a small-scale town. It is a kind of spatial lace that unifies the town’s different parts and enables the user to comprehend its spatiality with their mind and movement. That lace is also a traditional element: the porch.

As an element of architecture of monasteries and vernacular architecture over centuries (and even milennia), the porch is to the user a familiar and intimate form for the place of passage, staying, interaction, communication and transition between various ambiences. In the Centre, it is featured in the following elements:

Element 1: The entrance hall as the 3D cloister – a courtyard with galleries on multiple levels, connected by a panoramic elevator with the view towards various zones of the building and its environment, and with a possibility of opening up towards the future park/garden/sports park of the monastery.

Element 2: The conservatory as the porch – setting the axis of movement towards the monastery (the height difference is resolved within the building!), energy efficiency, semi-porous membrane between the multipurpose hall and the square.

Element 3: The corridor as the porch – a place for breaks and an informal working environment.

Element 4: The exhibition space as the porch – presenting information about Lepoglava on the facade and/or providing view of the part of the exhibition which requires natural light.

Completing circles

Having passed through the porches and found their place, the visitor has the opportunity to view, from multiple vantage points, the interior of the building, the park, the square, the rest of the Complex, the old building of the Prison, and even a big part of the natural surroundings. In other words, to complete, in a harmonious and unpretentious way, the circle of their experience, even if they do it unconsciously, focusing on the content and on communication.

Functional disposition

Entrance hall

• the place where the basic materials of the building meet (wood, stone, glass)

• the place of information, socialising and buying souvenirs

• the place where, by means of open galleries, spaces of different uses and ambiences meet each other (exhibition space, multipurpose hall, break-out space between workshops, the restaurant)

• the place of light, sun, and communicating with the square

• the openings towards the north can become doors (to provide access to the future park)

Exhibition space

• mono-volume exhibition space with a carefully designed disposition of columns provides freedom while setting up exhibitions

• scenario 1: a single big space (lit or dark, as needed)

• scenario 2: one central and one longitudinal space (a combination of natural light and a big black multimedia box

• scenario 3: fragmentation (open space with small multimedia islands)

• openings along the perimeter enable one to perceive the exhibition from the exterior (by viewing in and/or by means of posters and/or electronic screens)

Multipurpose hall

• retractable auditorium provides greater flexibility

• when flat, the floor is suitable for lace fairs, culinary events, dancing...

• auditorium seating is suitable for lectures, concerts, shows...

• it can be closed or open so that it connects with the northern zone of the square through the porch/conservatory

• it can be full of overhead natural light or completely dark

• windows at the top of the hall provide for natural ventilation

a combination of smooth reverberating panels and echo-preventing absorbers (acoustic design)

Workshops and administration

• between the workshops there is a break-out space: extended communication providing visual contact with the entrance hall, which connects it with the exhibition space

• it is possible to connect classrooms and to achieve visual contact with the break-out space owing to the glazed surfaces

City administration

• equality of orientation of spaces (east and west)

• no heat losses to the north and no problem with high-contrast southern light

• corridors are naturally lit at their ends; on the top floor by means of rooflights, too

• city administration can be reached via a special entrance with a security desk/surveillance room, and a separate staircase

• these spaces are connected with the visitors’ centre and the terrace of the roof restaurant

• being elevated off the ground provides tranquil working conditions

Restaurant

• located in an interesting quasi-pyramidal attic space where the building’s wings meet

• from the restaurant and its terrace, one can view the approach park, the monastery Complex, a part of the old prison building, and partially the Gaveznica mountain

• the restaurant is visually and physically connected with the main hall

Structure

The building’s structure follows contemporary trends in terms of ecology and simple assembly, and is closely bound to the concept of sustainability.

Foundations

Reinforced concrete foundations are made in accordance with the results of geotechnical exploration works.

Basement

The basement is a monolithic reinforced concrete structure made of walls, columns and slabs, connected with rcc foundations and waterproofed. Between the walls and slabs there are thermal-break elements (like Schoeck Isokorb), as thick as the insulation in the basement’s ceiling.

Loadbearing timber structure

The loadbearing structure of the part of the building that is above the ground level consists of cross laminated timber panels which make up the prefabricated elements for walls, ceilings and roofs. They are complete with final layers, openings and electrical installations in the factory, and simply and quickly transported and assembled at the building site. In addition to being practical and high-quality, this structure type is ecological in terms of its material, provides great seismic resilience, good and reliable fire safety, and natural microclimate regulation.

In addition to the cross laminated panels, the loadbearing structure comprises timber columns, beams, purlins and trusses.

Loadbearing masonry structure

The multipurpose hall with staircase and toilets is designed as a separate volume within the greater volume of the building. The walls are made of stone blocks from the local quarry, with reinforced-concrete horizontal and vertical ring beams. Due to its position on the inside of the facade glazing, during the winter this volume is a sort of a Trombe wall, while in the summer it serves as thermal mass to help bring keep the temperature down.

Outer shell

On the cross laminated timber panels there are rigid insulation boards made of wood fibres, which also serve as windproofing. Horizontal battens are fixed to the boards to carry vertical facade planks.

Roof

The 40-degree roof is designed as an extensive roof garden: red-brown sedum in substrate, root-resistant felt, layer of drainage/accumulation, waterproofing, thermal insulation, load bearing timber structure.

The roof plane above the restaurant terrace if fragmented with timber rafters.

Most of the southern roof plane is glazed, on timber substructure.

Floors

On the loadbearing timber structure between floors there are floating screeds with floor heating piping.

Non-loadbearing partitions

The partitions consist of timber substructure and gypsum-cardboard panels, with mineral-wool filling satisfying fire-safety standards.

Glazed facade

The southern facade is mostly glazed, on timber substructure. The roof glazing is like Onyx Solar (transparent photovoltaic modules integrated into layers of glass which stop infrared and ultraviolet rays).

Windows and exterior doors

Windows, rooflights and exterior doors are wood+aluminium elements, combining the ecological properties of wood with the durability (and cheap maintenance) of aluminium. The glazing has three layers, low-E, filled with Argon, with a fourth layer of glass on the outside protecting adjustable Venetian blinds. Rooflights are equipped with system like Velux Integra and Active, with automatic opening, closing and blinds.

Materials

The choice of materials shows the intention to combine the usage of ecological and local materials with creating functional and pleasant spaces. The nearby quarry could and should, in addition to the exising production of concrete aggregate, focus on economically more interesting production of bigger structural elements.

Exterior paving

The park paving between green circles features local dolomite gravel. The square is paved with slabs of local dolomite, which is known for its great resilience.

Timber structure

Wooden elements of the loadbearing structure and the ventilated timber facade are made of conifers (fir and spruce), from certified forests.

Masonry structure

Massive blocks are made of local dolomite and used in conjunction with reinforced-concrete ring beams.

Facade

Ecological wood-fibre panels are used for thermal insulation.

Floor covering

Due to the high number of users and the need to connect with the exterior ambience, the ground floor is paved with stone paving. Upper stories have natural linoleum covering (not pvc!), which is ecological, durable and easy to maintain.

Wall covering

The top layer of the cross laminated panels acts as their final layer in the interior. Parititions and walls in wet space feature gypsum-cardboard panels. The multipurpose hall features acoustic panels, in accordance with a special design.

Ceiling covering

False ceilings consist of gypsum-cardboard panels. In the multipurpose hall and the workshops/classrooms specially designed acoustic panels are used. Acoustic panels are also used in big common spaces (entrance hall and adjacent public spaces, restaurant) in order to eliminate echo.

Sustainable building concept

Materials and structure

Small ecological footprint in all phases, from extraction, manufacturing, transport, assembly and usage to recycling, is reflected in the choice of particular timber and masonry structure, as elaborated in the previous chapters. Using reinforced concrete is reduced to the necessary minimum. It is advisable to use the concrete whose aggregate comes from the local Očura quarry.

Building’s environmental impact during use

The sedum roof garden contributes to thermal insulation, biodiversity and pleasant microclimate, and prevents stormwater floods, while being easy to maintain.

The composting-toilet option without flushers and chemicals (e.g. the Clivus Multrum bio-composting chamber which is used in apartment blocks) helps to achieve significant water conservation and does an extremely big favour to the environment by eliminating the need for sewage. In case this option is not chosen, one should definitely filter rainwater and store it for flushing toilets and irrigating exterior gardens.

Basic concept

The aim of the design in this phase is to create the basis for designing an almost-zero-energy building. This is achieved by combining the following elements:

1.chosen principles of passive building (passive solar energy usage, heat mass, excellent thermal insulation of the building skin, elimination of thermal bridges, using heat recuperation in winter ventilation regime)

2. using renewable sources for heating water (solar collectors)

3. using renewable sources for heating in the interior (heat pumps)

4. producing electricity by means of photovoltaic modules

5. creating pleasant microclimate to avoid need for air-conditioning

6. using energy-saving electrical and heating appliances

7. centralised monitoring for the building’s energy system.

Summer and winter regime for passive solar energy use in multi-storey public spaces

In the winter, the sun heats the south-oriented conservatory which contains the big three-storey entrance hall and heats the big heat mass of the stone wall of the multipurpose hall. The accumulated heat is partially transferred to the interior of the hall, and partially to the public spaces in the building.

During the summer, the solar gain is drastically lower becasue of the foliage of deciduous trees, the bris-soleil effect of the substructure for the facade glazing, and natural ventilation by stack effect. The stone wall, with its shaded heat mass, contributes to the lowering of the interior temperature.

Heating of other spaces in the building

The heat pump system (with near-surface piping or a deep bore) combined with floor heating for the office wing of the building, uses the energy of the earth and a limited amount of electrical power, thanks to the small required difference between input and output water in the heating system. Each room has its own temperature sensor and automatic temperature regulation, combined with an occupancy sensor.

Insulating skin

Thick and high-quality thermal insulation for the entire building skin without thermal bridges also prevents overheating thanks to the ventilated timber facade.

Summer and winter ventilation regimes

Automatically regulated openings on the southern facade and the roof provide for efficient ventilation which is amplified in the summer due to the stack effect. In the entire building it is possible to achieve efficient cross ventilation of spaces and rooms, without the need for air-conditioning.

In the winter, the building is ventilated through heat-recuperation units.

Production of electricity

Transparent photovoltaic modules like Onyx Solar are built into the glazing of the southern roof surface. They prevent the influx of heat and UV rays through the glazing, thereby avoiding overheating. Since they are transparent and integrated into the glazing, the photovoltaic modules do not stand out from the composition of roof surfaces within the Complex.

Hot water production

Solar collectors are located at the top of the roof of the multipurpose hall, beneath the glazed roof of the building, so that they do not stand out from the composition of roof surfaces within the Complex. In that part of the glazed roof, there are no photovoltaic modules and the penetration of solar energy is unobstructed all the way to the collectors, which enables year-round hot water production. Additional heating is done by electrical power.

Minimising electrical energy consumption

By using LED lighting and (at least) A++ category of appliances one reduces the consumption of electricty. Additional reduction is achieved by using gravity for the hot water plumbing system and the rainwater plumbing system (for flushing toilets in case composting toilets are not used) because the water tanks can be located in the attic above the sanitary spaces.

Microclimate

Cross laminated timber panels which are used for exterior and interior loadbearing walls contribute to the reduction of temperature oscillations, but also provide for a pleasant amount of humidity because they are able to absorb and release sufficient amounts of water vapour, which eliminates the need for air-conditioning.