GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Hiša trentarskih vodnikov

Na Logu v Trenti

5232

Trenta, Slovénie

Architect

Ing-arh, Polona Čeh s.p.

Kranjska cesta 4, 4240 Radovljica

Owner

Triglavski narodni park

Ljubljanska cesta 27, 4260 Bled

triglavski-narodni-park@tnp.gov.si

User

Triglavski narodni park

Na Logu v Trenti, 5232 Soča

Contact Details

Jana Podgornik

Posoški razvojni center

jana.podgornik@prc.si

Other Information

Visits
The building is used as congress centre and to support social life of the local community.

History of this building goes back to the early 30s of the 20th century when a new complex of the Cantore barracks was built by Italians in order to defend the Rapallo border which ran along the nearby peaks. It was used as a kitchen and a dining place. Within the renovation in 1999 the original structure was refurbished and upgraded in line with the local building typology (Bovec house). Traditional wooden roof was built on top of the original concrete flat roof. In 2012 energy renovation took place. The entire building was insulated and organised as a multipurpose house. The case shows how non typical architecture (former military barrack) can be renovated and upgraded in a way that it gains traditional elements while following today's energy renovation standards.

GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Energy performance

48 kWh/m2.y

Climate Zone DFc

Altitude 628

Protection level Not listed

Conservation Area:
Oui

Level of Protection:
national park

Building age 1900-1944

Year of last renovation:
2012

Year of previous renovation:
1999

Building use multi purpose: educational center, seminar room, offices

Secondary use:
fire brigade

Building occupancy:
Unoccupied

Building area Net floor area [m²]: 514,0

Building typology:
Detached house

Number of floors:
2

Basement yes/no:
No

Number of heated floors:
1

Gross floor area [m²]:
618,0

Thermal envelope area [m²]:
917,0

Volume [m³]:
2071,0

NFA calculation method:

Construction type

Stone and concrete masonry + wooden roof structure

External finish:
Exposed woodwork

Internal finish:
Plastered (on substructure)

Roof type:
Pitched roof

+ MORE - LESS

Roof windows with breathtaking panoramic views. © PRC

Buildings supplied by the same heating system © PRC

Trenta village with complex of Cantore barracks. © TNP

Another remaining building of Cantore barracks. © PRC

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

Architecture: The design of the house and its design elements are a display of typical alpine architecture in the area of Bovec, which also includes the village of Trenta. The most recognised elements of Bovec house are the shape of the roof and the main entrance to the house with stairs and the balcony under a larger overhang. Traditionally the roof is very steep (up to 60 degrees) and covered with larch wood (skodlje). The roof slope of this building is 45 degrees. The roof ending called 'čop' is very speacial element and used only in Bovec house typology. Structure: The load-bearing walls on the ground floor are made of stone and 50cm tick. Balcony and upper part of the house is made of wood. Facade: The plinth is lined with natural stone. The facade of the ground floor is insulated with 6 cm layer of XPS and plastered as well as part of the external staircase. Stairs are made of stucco concrete slabs, the railing on the outside staircase is decorated with vertical boards and a profiled finish (handle) on the upper side. Closed part of the staircase on the ground floor and the roof gables at the front of the building are lined on the outside with vertically laid larch boards 15 - 20 cm wide which is typical for a local architecture. The windows on the ground floor remained existing from 1999. New wooden windows on the gables and in the "porch" are divided by wooden beams into four glazed fields. The entrance door and other doors to the rooms on the west side are wooden. Ridge orientation: NW – SE. Roof pitch: 45 degrees.

Urban context

Trenta village is located in the heart of the Triglav National Park, surrounded by beautiful alpine peaks. It lies along the road over the highest slovenian mountain pass Vršič which leads to the other side of the Slovenian Alps. The road was built in 1915 due to military needs. Nowadays the building belongs to the Triglav national park administration and is part of their educational centre. It is part of the cluster of buildings forming a settlement Na Logu in Trenta village.

State of repair

Conditions of the envelope

ROOF: The original concrete flat roof was pretty much unuseful for alpine climate. In 1999 traditional pitched roof was built on top of the existing one, which also allowed the possibility of using additional space in the attic. In 2012 energy renovation of the attic took place, including roof, gables and mezzanine slab. WALL: Stone bearing walls in the ground floor were uninsolated therefore one layer of thermal insulation was added in 2012.

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION

Stone masonry walls and plinth. This case shows how it is possible to integrate traditional elements in buildings that previously didn't have them and renovate them in a way that will continue to represent an important element of cultural heritage in this landscape.

Heritage Value Assesment

This building was originally part of military barracks and didn't fit into the cultural ladscape and vernacular architecture of the valley. The park administration decided to keep the main structure of the building but rebuild it in a way based on Bovec house type. They were able to maintain basic stone structure and the plinth lined with natural stone on the original building. New part of the conctruction is highlighting the most important elements from local architectural style.

Aim of retrofit

Renovation + Extension

The main objective was to set up a multi-purpose training center with a conference room, utility rooms and boiler room for heating system, thus giving a new purpose to the abandoned Italian barrack.

Was there any change of use?

The upper floor was previously not in use but with the energy renovation it was arranged for the needs of the multi-purpose hall. The Trenta fire brigade will continue to be located on the lower floor. A new boiler room with a heating system was built on this floor.

Was the intervention planned following a step-by-step approach?

According to the building law.

Lessons learned

The time of both world wars strongly affected the natural and cultural heritage of Soča Valley. The remains of the construction interventions of that time are still visible today. Some have already been given another purpose, while others are unhappily decaying, reminiscent of hard times and tarnishing the beauty of nature. Therefore, it is important to find new content for old objects and return them to life. It is interesting to see how non typical architecture (former military barrack) can be renovated and upgraded in a way that it gains traditional elements while following today's energy renovation standards.

Stakeholders Involvement

Public sector
Institute of the Republic of Slovenia for Nature Conservation
Tobačna 5. Ljubljana

Architect
Ing-arh, Polona Čeh s.p.
Kranjska cesta 4, 4240 Radovljica

Conservation Consultant
Institute for the Protection of Cultural Heritage of Slovenia
Poljanska cesta 40, 1000 Ljubljana

Energy Consultant
Šlibar inženiring d.o.o.
Motnica 17, 1236 Trzin

Structural Engineer
Karlovšek d.o.o.
Antona Skoka 7, 1230 Domžale

Tools used

Was the renovation process done following a specific methodology? No

RETROFIT SOLUTIONS

External Walls

Ground floor_Stone masonry

First floor - timber frame structure with wooden facade and roof

Ground floor_Stone masonry

Construction design of the exterior ground walls (stone masonry, λ = 1,7 W/mK) has changed only by adding a layer of thermal insulation (XPS 6cm, λ = 0,035 W/mK) which slightly improved it's thermal performance but still not enough to meet the conditions of a low-energy house. Since the ground floor in unheated and intended for garages and storage, thermal performance was not in the first place.

U-value (pre-intervention) [W/m2K]: 3,5 W/m²K U-value (post-intervention) [W/m2K]: 0,5 W/m²K

More Details

Original wall build-up

Stone - masonry:
500 mm

Plaster - Thick facade layer:
5 mm

Retrofitted wall build-up

Stone - masonry:
500mm

Insulation - Thermal insulation XPS:
60 mm

Plaster - thin facade layer:
3 mm

First floor - timber frame structure with wooden facade and roof

Traditional wooden roof was built in 1999 without any thermal insulation. Renovation in 2012 has altered the roof and the gables in terms of thermal performance. Thermal insulation layers were added in the roof assembly, gables were completely renovated and finished with vertically installed larch wooden boards. (Larch is a local tree).

U-value (pre-intervention) [W/m2K]: 6,0 W/m²K U-value (post-intervention) [W/m2K]: 0,171 W/m²K

More Details

Original wall build-up

Other - unknown:
100 mm

Wood - Timber structure:
160 mm

Retrofitted wall build-up

Wood - larch wood boards:
22mm

Air gap :
40 mm

Wood - Wooden plates (Agepan DWD):
16 mm

Insulation - Thermal insulation :
160 mm

Wood - wooden plates (OSB):
16 mm

Insulation - Thermal insulation:
60 mm

Cladding - Plaster board:
15 mm

Windows

Facade windows

Roof windows

Facade windows

The windows on the ground floor remained existing from 1999. New wooden windows on the gables and in the "porch" are divided by wooden beams into four glazed fields.

Existing window U-value Glass [W/m2K]: 5,0 New window U-value Glass[W/m2K]: 1,2 Existing window U-value Frame [W/m2K]: 5,0 New window U-value Frame [W/m2K]: 1,1

More Details

Existing window type	Coupled window
Existing glazing type	Single
Existing shading type	NA

New window type	casement window
New glazing type	Double
New shading type	NA

Roof windows

Roof windows were replaced with new energy efficient windows with double glazing.

Existing window U-value Glass [W/m2K]: 5,0 New window U-value Glass[W/m2K]: 0,9 Existing window U-value Frame [W/m2K]: 5,0 New window U-value Frame [W/m2K]: 1,4

More Details

Approximate installation year

2012

New window type	Roof window - Centre pivot
New glazing type	Double

Other interventions

ROOF

OTHER

MEASURES TO INCREASE AIRTIGHTNESS

ROOF

Before 2012 there was no thermal insulation in the roof assembly. Thermal insulation was applied internally to maintain the existing wood shingle roof. Timber structure was also preserved. To improve the supply of a daylight in the conference room in the attic, various roof windows were installed with approval of the heritage office.

Flat concrete roof was originally built in 1936. In 1999 traditional pitched roof was built on top of the former flat concrete roof. Energy renovation of the attic took place in 2012.

Typical traditional shingles made of larch wood. © PRC

U-value (pre-intervention) [W/m2K] 8 U-value (post-intervention) [W/m2K] 0,151

More Details

Original roof build-up

Shingles - larch wood:
50 mm

Other - timber structure:
140 mm

Shingles - larch wood:
50 mm

Retrofitted roof build-up

Other - air gap:
100 mm

Other - Damp Proof Membrane:
1 mm

Other - Thermal insulation:
14 mm

Other - Thermal insulation:
8 mm

Other - Gypsum board:
14 mm

Shingles - larch wood:
50 mm

OTHER

MEASURES TO INCREASE AIRTIGHTNESS

The upper floor only.

HVAC

HEATING

DOMESTIC HOT WATER

HEATING

The old heating system on fossil fuels (propane-butane) was replaced by a biomass boiler (wood chips). In the renovated building, there is a new boiler room with a Fröling furnace with a power of 150 kW with two storage tanks for 6000 liters of hot water. The biggest gain is efficient heating with significantly lower costs and locally supplied wood chips. The new heating system will supply the renovated building as well as the main building of the TNP museum and info center.

More Details