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Hohe Strasse, Hanover

Description

The building was complete in need of renovation. The exterioir walls were partial damp and the building services completely outdated. On the attic floor, there were still some individual stoves or a gas-boiler. Damages due to damp to floor and ceiling beams were caused by the damaged roof. For the projected modernisation, only the exterior walls, ceiling and the base plate survived.

The three exterior walls as well as the base plate were equipped with a interior insulation. Frontage and roof were built in wood frame construction with 40 respectively 48 cm heat insulation. Minimizing thermal bridges succeeded through consequently separating existing primary structures from existing outside components and the carefully realisation of airtight taping. Therefore, conventional heating and a gas-connection were not necessary. Heating in winter is realised with a compact unit with smallest heat pump, passive heat transmission and the comfort ventilation system combined with heat revovery. In summertimes, a solar collector overtakes approximately the complete water-heating.

Involved parties

Client:

Adele Rebel and Till Hahlbeck

Design:

architectual office (21+), Hanover, and clients

Realization:

personal contribution

Building data

BUILDING TYPE:

Singe-family-house (backyard building with three exterior walls)

LOCATION:

Hanover-Linden

YEAR OF CONSTRUCTION:

before 1900 (rebuilt old stock)

MODERNIZATION:

2004

RESIDENTIAL UNITS:

1

HEATED USABLE SPACE:

ca. 120 m2

SUBSIDIES:

KfW, BAFA, proKlima

Initial condition

EXTERIOR WALLS:

24 cm single skin walls

HTC ? 1.8 W / (m² K)

WINDOWS:

Wooden or plastic windows with double glazing

HTC ? 2.6 W / (m² K)

ROOF:

completely without thermal insulation

HTC ? 5.2 W / (m² K)

BASEMENT CEILING:

uninsulated basement ceiling

HTC ? 2.4 W / (m² K)

VENTILATION:

Window ventilation as well as typical old building joints and cracks

HEATING:

Individual stoves and gas-boiler

Modernization in detail

EXTERIOIR WALLS:

on existing masonry exterior walls inside bearing wood construction with a total of 20 cm heat insulation, quality of 0.035 W / (mK), HTC = 0.14 W / (m² K)

South side (backyard): new wood frame construction with 12 cm heat insulation system, 20 cm insulation between wood cellular beams and 6 cm insulation between substructure, HTC = 0.08 W / (m² K)

WINDOWS:

Passive house windows with 3-pane glazing

HTC = 0.75 W / (m² K)

ROOF:

Wooden beams with 36 cm heat-insulation and substructure with 12 cm insulation, quality 0.035 W / (mK), HTC = 0.08 W / (m² K)

BASEMENT CEILING:

new construction on existing concrete floor: floor covering on particle board, wood beams with 30 cm insulation, quality of 0.0035 W / (mK), HTC = 0.11 W / (m² K)

VENTILATION AND HEATING:

Compact ventilation unit with integrated passive heat exchangers and micro-heat pump, solar water heating system, 5 m² absorber surface, 250-liter tank, heating the rooms exclusively via ventilation system and a radiator

COOLING:

no active cooling installed

Measured values

AIRTIGHTNESS:

n50 = 0,35 h-1

Calculated values

Calculation method: Passivhaus planning package; Initial values: Hanover building typology

HEATING ENERGY NEEDS:

BEFORE

300 kWh/(m²a)

AFTER

28 kWh/(m²a)

SAVINGS

91 %

TOTAL ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:

BEFORE
GAS

458 kWh/(m²a)

ELECTRICITY

16 kWh/(m²a)

AFTER
ELECTRICITY

37 kWh/(m²a)

PRIMARY ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:

BEFORE

555 kWh/(m²a)

AFTER

97 kWh/(m²a)

SAVINGS

83 %

CO2-EMISSIONS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:

BEFORE

122 kg/(m²a)

AFTER

23 kg/(m²a)

SAVINGS

81 %