GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Sankt Christoph

Sankt Christop

85643

Steinhöring, Germany

Architect

Architekturbüro Lindner

Am Pfründeweg 5, 85457 Wörth

Owner

User

Contact Details

Ahmed Khoja, Alicia Davis

Munich University of Applied Science

ahmed.khoja@hm.edu, alicia_maria.davis@hm.edu

Other Information

The former farmhouse was built in 1779 and consisted of a residential part as well as of a stable and a barn floor. It was one of the first farmhouses to be listed as a monument in Bavaria. The electrical system partially dated back to the beginning of electrification and the building was heated with a single oil stove and a wooden stove. The aim was to renovate the former farmhouse in a monument protecting and energetic manner, without losing the character and the substance of the historic building. Whereas the former living area is used for holiday guests, a new residential building was built into the former stable and barn floor, maintaining distance to the existing building envenlope.

GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Energy performance

76,53 kWh/m2.y

Climate Zone warm temperate, fully humid, warm summer

Altitude 519 m a.s.l.

HDD 3730

CDD 47

Protection level Listed

Conservation Area:
No

Level of Protection:
the building is classified as a historical monument

Building age 1700-1800

Year of last renovation:
2019

Building use Residential (rural)

Secondary use:
NA

Building occupancy:
Permanently occupied

Number of occupants/users:
3

Building area Net floor area [m²]: 237,0

Building typology:
Single-roof house barn

Number of floors:
2

Basement yes/no:
No

Number of heated floors:
2

Gross floor area [m²]:
325,0

Thermal envelope area [m²]:
640,0

Volume [m³]:
1270,0

NFA calculation method:
NGF (de)

Construction type

Ground floor: masonry; Upper floor: trusses with Bundwerk facade

External finish:
Ground floor: rendered; Upper floor: wooden Bundwerk

Internal finish:
Ground floor: rendered; Upper floor: no internal finish

Roof type:
Pitched roof

+ MORE - LESS

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

The building was constructed in 1779 and used to function as a farmstead. The building consisted of a living area, a stable, a barn floor and a hay loft, situated underneath a single roof. The building measures a length of about 30,5m, depth of around 10m and a height of approximately 7,1m from ground to roof ridge. The facades of the massive constructed ground floor is coated with whitewash, whereas the upper wooden construction is planked with wooden slats and slates and furthermore presents traditional craftsmanship from the region. Such as the so-called “Zierbund”, which are decorated timber framings made by carpenters.

Urban context

The building is located in the center of St. Christoph in direct proximity to the steep ascending hill leading up to the church in the West.

State of repair

Conditions of the envelope

Constructional interventions from the past have partially caused serious damage to the static system.

Description of pre-intervention building services

Before the refurbishment the eastern building section was used for residential purposes and was equipped with all necessary service connections.

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION

The mixed masonry, the Bundwerk-construction as well as the roof trusses were preserved and retrofitted.

Heritage Value Assesment

Studies have shown, that the construction of the byre-dwelling started in 1779/1780. The building had to undergo various structural changes in the course of the 19th century until approximately the first quarter of the 20th century. Some of them were quite severe, such as the suspected replacement of the wooden construction on the ground floor by masonry. However, in the further process it can be seen that the structural modifications were less radical. They a part of a series of continuous adjustments for agricultural use and living comfort. Despite the ongoing local measures, in substance the house is of historic significance. Worthwhile mentioning are original doors with their initial fittings, the hardly changed block construction with its preserved surface, the bundwerk with its decorated boards and many more details represent a farmhaus from the late 18th century. The farmhouse is one of the first buildings, which was listed.

Aim of retrofit

Renovation

The aim of the retrofit was the preservation of the listed building and the construction of a residential unit in accordance with historical preservation. The solution is a "house within a house" concept and thus only has little impact on the historic facade structure. The existing wooden windows were replicated and single wooden planks of the external facade were replaced by glas plates.

Was there any change of use?

The stable, the barn floor as well as the hay warehouse were turned into a residential unit.

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

In coordination with the Bavarian state office for the preservation of monuments a restructuring plan was established.

Lessons learned

Unplanned work and changes during the renovation process require close consultation with the monument protection authority

Stakeholders Involvement

Public sector
district administration of Ebersberg
Eichthalstraße 5, 85560 Ebersberg

Architect
Architekturbüro Lindner
Am Pfründeweg 5, 85457 Wörth

Conservation Consultant
Dr. Sahler (Bavarian state office for the preservation of monuments)
Hofgraben 4, 80539 München

Energy Consultant
Martin Tauchmann
Bräubogen 5, 83539 Forsting

Structural Engineer
Martin Tauchmann
Bräubogen 5, 83539 Forsting

Other
Bavarian state office for the preservation of monuments
Hofgraben 4, 80539 München

Tools used

Was the renovation process done following a specific methodology? No

Energy calculation EnEV calculation as per DIN 4108-6 and DIN 4701-10
Other dimensionally correct measurement, damage mapping, pollutant analysis

RETROFIT SOLUTIONS

External Walls

solid construction

In the course of the renovation, the masonry in the ground floor was plastered. Newly installed walls in the inside were erected in a wooden structure and insulated with wood fibre insulation.

Erection of a new building structure inside of the former stable and barn floor area. The external facade is preserved.

U-value (pre-intervention) [W/m2K]: 1,3 W/m²K U-value (post-intervention) [W/m2K]: 0,58 W/m²K

More Details

Original wall build-up

Plaster - lime plaster:
30 mm

Brick - mixed brick-work :
500 mm

Plaster - lime plaster:
30 mm

Retrofitted wall build-up

Plaster - insulating plaster on the basis of lime:
50mm

Brick - mixed brick-work :
500 mm

Plaster - insulating plaster on the basis of lime:
30 mm

Painting (frescoes) - painting on the basis of lime:
0 mm

Windows

wooden windows

In the course of the renovation, new wooden windwows as well as metal windows were integrated.

On the ground floor of the former living and stable area: The windows were rebuild on the basis of the specifications of the heritage department. Furthermore the windows in the former living area were downsized to it's original size (in the course of previous renovations the window sizes were modified) . The reduced size of the window opening only had minor effects on the light conditions and is sufficient for the natural lighting of the building section used as a holiday apartment. On the upper floor of the former barn and stable area: New windows were installed in the new wooden wallboard.

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

More Details

Existing window type	Casement window
Existing glazing type	Single
Existing shading type	Outer shutter

New window type	Casement window
New glazing type	double and triple
New shading type	NA
New window solar factor g [-]	0,6

Other interventions

ROOF

GROUND FLOOR

MEASURES TO INCREASE AIRTIGHTNESS

ROOF

In the course of the renovation, the roofing was renewed (insulation in between the rafters and on-roof insulation).

The existing roof structure is preserved. The new and sinter fired roof covering is due to its red colourfulness closest to the original roof tiles. The existing tiles made of concrete were strongly weathered and derived from former renovation works.

U-value (pre-intervention) [W/m2K] 0 U-value (post-intervention) [W/m2K] 0,21

More Details

Original roof build-up

Tiles - concrete roofing tile (“Frankfurter Pfanne“):
50 mm

Other - wooden roof structure:
200 mm

Retrofitted roof build-up

Tiles - roof tiles on batten and counter batten:
130 mm

Other - wood fibre insulation:
80 mm

Other - rafters with mineral wool in between:
120 mm

Other - batten:
40 mm

Other - plasterboard:
15 mm

GROUND FLOOR

Integration of a new building structure in the existing building envelope.

The external facade is preserved.

U-value (pre-intervention) [W/m2K] 0 U-value (post-intervention) [W/m2K] 0,33

More Details

Original groundfloor build-up

Other - pavement and wooden floorboards:
30 mm

Other - pavement and wooden floorboards on top of the ground:
30 mm

Retrofitted groundfloor build-up

Finish - flooring:
50 mm

Other - cement screed:
60 mm

Insulation - PUR-insulation:
50 mm

Concrete slab - reinforced concrete slab:
250 mm

MEASURES TO INCREASE AIRTIGHTNESS

The newly integrated residential unit benefits of the existing building envelope, which provides an additional building cover to the dwelling.

Airtightness (pre-intervention) [ach@50Pa] 0 Airtightness (post-intervention) [ach@50Pa] 0

HVAC

HEATING

VENTILATION

DOMESTIC HOT WATER

HEATING

There was no heating system before the renovation.

Heating is distributed through floor and wall heating and does not affect the existing building structure.

More Details

	New primary heating system
New system type	Heat pump
Fuel	Biomass
Distribuition system	Radiating floor and radiating walls
Nominal power	NA kW

VENTILATION

There was no ventilation system before the renovation.

The newly installed ventilation system does not compromise the existing structure of the historic building

More Details

Original roof build-up	New ventilation system
Type ventilation system	Centralized
Type flow regime	NA (Natural)
Heat recovery	Yes
Humitidy recovery	No
Nominal power	N/A kW
Electric power	0,0 kW
Control system	N/A

DOMESTIC HOT WATER

There was no domestic hot water system before the renovation.

The hot water system is connected to the central heating system.

More Details

	New DHW system
Type	with heating system
Hot_water_tank	Yes
With heat recovery	Yes

Energy Efficiency

Energy Performance

Energy performance certificate: energy pass
Voluntary certificates: No

Energy Use

Heating
Primary Energy 32,0 kWh/m2.y
Consumption_estimation_After: 76,53 kWh/m2.y

Primary Energy
Consumption_estimation_Calculation_method: demand as per EnEV calculation

Documents:

Energieausweis.pdf

energy pass

Consumption_estimation_Including_DHW: Yes
Consumption_estimation_After: 32,0 kWh/m2.y

Measured Parameters

Construction
Type_of_monitoring: Punctual
Description: measurement of pollutants

Internal Climate

Daylight

In order to expose the new building structure to sufficient daylight, some wooden planks of the Bundwerk-facade were replaced by glass plates.

Costs

Financial Aspects

The project was able to benefit from various fundings (state office for the preservation of monuments, German foundation of preservation order)

Investment Costs

Total investment costs
650.000,00 (total)

Running Costs

Lifecycle cost
No