GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

House Pernter

Main Road 20

39040

Truden in the natural preserve, Italia

Contact Details

Christoph Mayr Fingerle

Architekt

arch@mayrfingerle.com

39 0471 975091

Other Information

own project

Related publications
architektur südtirol 2017/2018

The value of the simplicity. The renovation of the house Pernter in Truden is based on the character of the village. The building from 1923 was formerly used entirely for agricultural purposes. The typical Tyrolean style of the construction is expressed in the compact design with residential house, stable and barn under one roof. New user requirements and structural damages made the renovation necessary. The aim was to optimise the energy balance without altering the existing building envelope, because the rough, living plaster surface is one of the characteristic features of the houses in Truden. Emphasis was placed on the use of regional materials and the preservation of old building elements to preserve the atmosphere of the farmhouse. This resulted of all this sensitive measures is a modern living space, equipped with materials of lasting value, which start into the next century.

GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Energy performance

26,50 kWh/m2.y

Climate Zone F

Altitude 1100 s.l.m.

HDD 268

CDD 0

Protection level Not listed

Conservation Area:
No

Level of Protection:
NA

Building age 1900-1944

Year of last renovation:
2017

Year of previous renovation:
1965

Building use Residential (rural)

Secondary use:
Agricultural & Fishery

Building occupancy:
Permanently occupied

Number of occupants/users:
5

Building area Net floor area [m²]: 242,0

Building typology:
Detached house

Number of floors:
3

Basement yes/no:
No

Number of heated floors:
2

Gross floor area [m²]:
336,0

Thermal envelope area [m²]:
225,0

Volume [m³]:
642,0

NFA calculation method:
Useful area (it)

Construction type

Stone masonry wall

External finish:
Rendered

Internal finish:
Plastered (on hard)

Roof type:
Pitched roof

+ MORE - LESS

color concept: earth tone color and light green

original window, preserved and repainted

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

Haus Pernter is a former farmer's building dating from 1923, measuring 17,80m in width and 11,50m in depth. Historically, the volume unites two distinct uses: the residential part in the West and the agricultural part in the East. The house has a groundfloor layout typical for farm buildings in the region of South Tyrol. The rooms are arranged like cells around a central corridor ('Labe'). The 2017 retrofit consisted of a general renovation and an internal restructuring, resulting in two separate residential units. The intervention aimed to unveil the aesthetic potential and archaic power of the stone masonry.

Urban context

Located on 1.100 m above sea level, Haus Pernter is situated in the East of the village center, facing the main road. It is positioned parallel to the slope and thus enjoys a generous view to the valley. The municipality of Truden im Naturpark belongs to the district of Überetsch-Unterland and counts 1.049 inhabitants. Bordering the province of Trento, the village is located on the German-Italian language boundary. The enclosed village of Truden with its typical irregular plots spreads on the south-facing slopes of Cislon and lays adjacent to an old bridle path, that connects the basin of Unterland with the Val di Fiemme.

State of repair

Conditions of the envelope

The building has no basement, thus foundations lay just beneath the ground level. The original groundfloor pavement in the agricultural part is rammed earth, while in the residential part the floor was laid directly on the rammed earth. In the 1960s, a waterproof sealing layer was introduced to improve the indoor climate. The outer walls consist of large blocks of local stone, probably originating from a nearby quarry. The roof frame is a traditional timber construction covered with typical terracotta tiles.

Description of pre-intervention building services

Before the intervention the groundfloor of the building was heated with a hearth in the kitchen and a wood-fired stove in the 'Stube', the traditional central living room. On the upper floor, besides the kitchen hearth there was a stove for wood pellets located in the corridor. For domestic hot water in the bathroom an electric boiler was used.

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION

The most significant space is the groundfloor with its barrel vault and two lunettes. It was the aim of the project to preserve the soul of the building by recognizing its potentials and bringing them to the foreground. The characteristic features of the building are its stone masonry, the rough plaster, the timber elements and the earth tone colors. Wherever possible, original surfaces and building elements (i.e. internal doors) were preserved, new elements such as the windows were built as re-interpretations of the original typologies. From an architectural point of view, the project seeks to preserve the building's plain aesthetic of the ordinary. This was achieved through understanding and adapting the pragmatic logic of the context. Instead of a total make-over, punctual interventions were made were necessary; the materials used are simple and rough and allow for aging. During renovation, historic wall paint was found and uncovered. With this discovery, the building's 1920s color scheme became readable and was referenced in the renovation project's color concept. A historical earth tone color was chosen for the facade, a light green for the window shutters. The external doors were made of natural, lightly brushed larch wood. A characteristic external window was preserved and complemented by a new window with insulation glazing on the inside. The edges of all window and door soffits were rounded up until the height of two meters. This theme was preserved in all original openings. The balcony railing is made of wooden boards with a variety of cut-out patterns, referencing traditional examples.

Heritage Value Assesment

In close collaboration with the owner and with the help of historical photographs, the architect aimed to gain an understanding of the original construction principles. Where considered meaningful and feasible, the historical situation was restored. An example for this is the removal of the annex. It was the aim of the renovation project to preserve the aura and atmosphere of the house while remaining within a quite limited budget. For this reason, priorities had to be set in accordance with the client: The central objectives were to achieve a good living comfort and to unveil the simple but powerful architectural language of the building. Due to the limited economic means the architect decided to work with a strategy of acupuncture, strengthening the existing building punctually. Old building element were maintained were possible and repaired or exchanged were necessary. This patchwork operation is typical for traditional rural architecture, that has always had very limited means at its disposal.

Aim of retrofit

Renovation

The aim of the renovation was to maintain as much as possible of the existing building substance, while significantly improving the building's comfort and energy efficiency.

Lessons learned

When working on renovation projects, a detailed architectural survey and the inventory of all elements worthy of preservation are vital for further planning. It is also important to search for possible previous paint layers on the interior and to uncover the ceiling and floor structures. Particularly in the case of a tight budget it is crucial to have as much information as possible about the state of the building.

Stakeholders Involvement

Energy Consultant
Oscar Dibiasi
Hügelgasse 14, I-39040 Montan
info@oscar-dibiasi.com
Tel.333 1403644

Structural Engineer
Marcus Varesco
Fleimstalerstraße 1 , 39044 Neumarkt
marcus@bampi-varesco-steiner.it
Tel.339 6561576

Tools used

Was the renovation process done following a specific methodology? No

Energy calculation NA
Hygrothermal assessment NA
Life Cycle Analysis (LCA) NA

architektur südtirol 2017/2018

RETROFIT SOLUTIONS

External Walls

Exterior Wall nord side air shaft

Exterior Wall nord side top floor

Groundfloor plinth insulation

Exterior Wall nord side air shaft

The underground plinth in the North was treated with a cold bitumen coating and insulated with a 16 cm perimeter insulation that reaches from the foundations to the first floor.

As the wall is located in proximity to the shaft, the addition of the insulation layer is not visible from the outside.

Concrete wall with 16cm perimeter insulation

Top view of shaft with perimeter insulation and steel cages

View of concrete shaft with sheet metal cover

U-value (pre-intervention) [W/m2K]: 1,552 W/m²K U-value (post-intervention) [W/m2K]: 0,192 W/m²K

More Details

Original wall build-up

Plaster - Innenputz Kalk:
15 mm

Stone - Aussenwand Stein:
500 mm

Dry-lining - Betonwand unverputzt:
200 mm

Retrofitted wall build-up

Insulation - Perimeterdämmung:
160mm

Other - Flexilabdichtung:
10 mm

Exterior Wall nord side top floor

From there, an stone wool insulation with the same thickness was applied until the upper edge of the facade. This facade insulation is only applied on the North side, that during winter cools down the most.

U-value (pre-intervention) [W/m2K]: 1,77 W/m²K U-value (post-intervention) [W/m2K]: 0,194 W/m²K

More Details

Original wall build-up

Plaster - Innenputz Kalk:
15 mm

Stone - Aussenwand Stein verputzt:
500 mm

Plaster - Kalkzementputz Bestand:
20 mm

Retrofitted wall build-up

Insulation - Fassadendämmung Steinwolle:
160mm

Plaster - Spritzwurf Putz grobe Körnung:
10 mm

:
0 mm

Groundfloor plinth insulation

The plinth of the East-, West- and South-facade is surrounded by a 50 cm wide stripe of foam glass pebble, reaching from the foundations to the ground level. It allows moisture, originating from precipitations or the soil, to evade.

application subterranean, invisible

More Details

Original wall build-up

Stone - Aussenwand Stein Bestand:
650 mm

Retrofitted wall build-up

Insulation - Glasschaumgranulat ( λ=0,08 W/mK):
500mm

Air gap - Schotterstreifen:
250 mm

Windows

window living-room

All windows were replaced with new elements to fulfill current technical standards. The new lattice windows and balcony doors are close to the original, but have a double security glazing. Windows: Spruce wood, double laminated safety glazing U-value: 1,1 Shutters: Spruce wood, folding elements with fixed horizontal battens. Color: light green, as in many traditional farm houses

timber frame with indigenous larch with UV protection glaze

Existing window U-value Glass [W/m2K]: 5,8 New window U-value Glass[W/m2K]: 1,1 Existing window U-value Frame [W/m2K]: 5,0 New window U-value Frame [W/m2K]: 1,8

More Details

Existing window type	Casement window
Existing glazing type	Single
Existing shading type	Outer shutter
Approximate installation year	1923

New window type	Casement window
New glazing type	Double
New shading type	Outer shutter in wood
New window solar factor g [-]	0,0

Other interventions

GROUND FLOOR

OTHER

GROUND FLOOR

Usually the Floor covering was built directly on the soil. This led to the renewal of the groundfloor flooring: in order to block the cold from the soil, a 20cm layer of XPS was laid. On top of this insulation the new floor structure with the underfloor heating was installed.

application subterranean, invisible

More Details

Original groundfloor build-up

Other - Lehmboden:
0 mm

Concrete slab - Magerbeton:
100 mm

Finish - Riemenboden:
32 mm

Retrofitted groundfloor build-up

Concrete slab - Magerbeton:
50 mm

Insulation - XPS (Floormate 500-A) 2x10:
200 mm

Concrete slab - Leitungsführung Schaumbeton:
100 mm

Insulation - Dämmung:
50 mm

Other - Estrich mit Gittermatten und Fussbodenheizung:
60 mm

Finish - Riemenboden geklebt:
32 mm

OTHER

Thermal insulation takes place on the ceiling of the 1st floor. 8cm of XPS are laid in-between, another 12cm above the wooden beams.

oriented structural board - section building floor

HVAC

HEATING

VENTILATION

DOMESTIC HOT WATER

HEATING

As a part of the renovation works, a central heating plant was installed. This led to the renewal of the groundfloor flooring: in order to block the cold from the soil, a 20cm layer of XPS was laid. On top of this insulation the new floor structure with the underfloor heating was installed. Similarly, underfloor heating was installed on the 1st floor. The ducts were laid between the structural wooden beams and insulated with light aggregate. On top of the beams, footfall sound insulation and finally the screed layer with underfloor heating were laid. The heating plant is fueled by wood pellets and located underground on the outside, allowing for the realization of additional spaces such as a deposit and a working space within the existing building. The existing chimneys were maintained and renovated were needed. Were no longer needed, the chimney shafts were used as installation shafts for HVAC ducts. The wood-fired stove on the groundfloor remains active and in the kitchen a new wood-fired hearth was installed to complement the electric hotplates.

Pellets are stored outside of the building in an underground steel tank.

ETA PU Pellet boiler with modulating firing control

More Details

	New primary heating system	New secondary heating system
New system type	Boiler	Stove
Fuel	Biomass	Wood
Distribuition system	Radiating floor	Air
Nominal power	14,9 kW kW	NA kW

VENTILATION

In the bathroom on the groundfloor facing North mechanical ventilation replaces the window in order to guarantee sufficient ventilation. The device also is equipped with a heat recovery function. For the dehumidification of the building there is a narrow shaft on the North of the building. The existing opening of the shaft was only maintained on the North-East edge of the building, while the remaining surface was covered. In order to guarantee a good cross ventilation, the entrance door to the shaft on the other side has a large ventilation grill.

More Details

Original roof build-up	New ventilation system
Type ventilation system	Room-by-room
Type flow regime	NA (Natural)
Heat recovery	Si
Humitidy recovery	No
Nominal power	NA kW
Electric power	kW
Control system	NA

DOMESTIC HOT WATER

During summer, the demand for domestic hot water is to a large extend covered by the solar system.

More Details

	New DHW system
Type	with heating system
Hot_water_tank	Si
With heat recovery	No

RENEWABLE ENERGY SYSTEMS

SolarThermal

Biomass

SolarThermal

The solar-thermal plant was installed as a large area collector on the roof of the adjacent building, taking advantage of its favorable inclination and position. In the summer months, a large part of the warm water demands can be covered. The plant is a custom built high-performance large area collector, made of a powder-coated aluminum hollow-cell frame profile with lateral thermal insulation and a highly selective copper absorber.

The solar-thermal plant was installed on the roof of an adjacent building and is invisible from the main building and the street.

The solar plant was integrated in the roof of an existing pavilion located below the house.

More Details

	SolarThermal System
Type	Flat collector
Collector area	8,0 m²
Elevation angle	68,0
Azimuth	0,0
Overall yearly production	5,0 kWh
Heating_contribuition	0,0 kWh
DHW contribuition	3,0 kWh
Cooling contribuition	0,0 kWh

Biomass

ETA PU Pellet boiler with modulating firing control

Pellets are stored outside of the building in an underground steel tank.

separate boiler room inside the building

ETA Prospekt Pelletskessel Unit 7 - 15kW

Libretto installazione EASY-PELLET neutr

More Details

	Biomass System
Type
Storage size
Origin of biomass
Overall yearly production	14,0 kWh

Energy Efficiency

Energy Performance

Energy performance certificate: Energy Certificate

Energy Use

Documents:

Energieausweis Haus Pernter (002).pdf

Energy Certificate

Consumption_estimation_After: 26,50 kWh/m2.y

Primary Energy
Consumption_estimation_Calculation_method: NA

Internal Climate

Temperature

medium 20° C in the wintertime in the heated rooms

Indoor Air Quality

good

Daylight

very good

Acoustic Comfort

gut

Costs

Financial Aspects

The architect worked with a fixed budget determined by the client. In order to stay within the given budget, some of the commissioner's wishes such as the realization of bay-windows and thermal insulation on all facades could not be fulfilled. Also, the roof framework and covering could not be renovated. These cuts allowed for the realization of an underground pellet storage tank in steel and a solar-thermal plant. Both interventions are positioned out of sight and therefore do not take up space within the existing building or impact its appearance. The decision to insulate the Northern facade only is supported by the geographical exposition of the building: the other three sides are well exposed to the sun throughout the year. Besides the economic reasons – an insulation on all sides would have exceeded the budget – there was an architectonic argument, too: the re-making of all four facades would have drastically changed the tactile experience of the building's exterior. With a current-day plaster applied on an insulation layer it would have been impossible to preserve the character of the historical exterior.

Investment Costs

Total investment costs
1500 € (per m2)
Amount includes: The above mentioned costs contain all renovation work on the facade and the interior, the renewal of all building services (electricity and heating), the exterior pavings as well as the solar-thermal plant and the construction of a timber shed for bicycles and motorbikes.

Running Costs

Total annual energy cost
2100 (total)

Annual electricity cost
1500 (total)

Lifecycle cost
No