Client:
Building owner community Allerweg
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Allerweg, Hanover
Description
The beginning was the modernization of the building in the street Allerweg 8 in 2006. The purpose of the environmental remediation were comfortable and actual apartments. The ground-plan was increased in the size. In some cases, the apartments were connected. Every flat has a modern bathroom and a balcony.
To decrease the energy demand, the building was future-oriented modernized with elements of passive houses: The exterior walls got a well insulation of heat. On top of that, the old windows were replaced by new lacquered wooden windows with heat-insulating triple glazingheat-insulating triple glazing, which is integrated thermal bridge-free into the wall construction. The heating comes from comfort-ventilation systems with reheating functions. All old radiators were taken out, only a single radiator was installed for comfort in the bathroom. Now, heating and hot water generation takes place in the neighbouring cellar via district heating network. Although the modernization of the building in Allerweg 10 is not finished yet, the consumption of energy in Allerweg 8 amounts to 17 kilowatt hour per square meter in the first winter.
Involved parties
Design:
agsta Architekten und Ingenieure, Hanover
Building data
Building type:
Apartment house
Location:
Hannover-Linden
Year of construction:
1910
Modernization:
2006-2010
Residential units:
18
Heated space:
1.116 m²
Subsidies:
KfW, dena-Modell-projekt, proKlima
Initial situation
EXTERIOIR WALLS:
36,5 cm fairfaced brickwork, HTC = 1,5 W/(m2K)
WINDOWS:
Wooden windows with 2-pane insulating glazing, HTC ? 2.7 W/(m² K)
ROOF:
uninsulated purlin roof with tiles
BASEMENT CEILING:
uninsulated ferro-concrete ceiling
VENTILATION:
Window ventilation, as well as typical old building joints and cracks
HEATING:
Space heating in part with coal stoves and electric night storage heating, hot water via electric water heater
Modernization in detail
EXTERIOIR WALLS:
24 cm heat insulation system in quality of 0,035 W/(mK), HTC = 0,14 W/(m2K)
WINDOWS:
new wooden windows with 3-pane glazing, window HTC = 0.8 W / (m² K)
ROOF:
new roof structure with a reduced amount of wood, between 27 cm cellulose insulation quality of 0.040 W / (mK), HTC = 0.15 W / (m² K)
BASEMENT CEILING:
new floor construction with floating floor and insulation in quality of 0.030 W/(mK), additional insulation of the basement ceiling from below, U-value = 0.12 W / (m² K)
VENTILATION:
each apartment has a comfort ventilation system with heat recovery
HEATING:
heating und water heating by district heating, heat distribution through the ventilation system and bathroom radiators
AIR CONDITIONING:
no active air conditioning installed
Measured values
AIRTIGHTNESS:
n50 = 1,33 h-1
including leaks on home partition to the next house, they will be reduced after the completion of Allerwegs 10th
Calculated values
Calculation method: Passivhaus planning package; Initial values: Hannover building typology
HEATING ENERGY NEEDS:
BEFORE
150 kWh/(m²a)
AFTER
15 kWh/(m²a)
SAVINGS
90 %
TOTAL ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
Coal
120 kWh/(m²a)
Electricity
114 kWh/(m²a)
AFTER
Districht heating
38 kWh/(m²a)
Electricity
19 kWh/(m²a)
PRIMARY ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
425 kWh/(m²a)
AFTER
65 kWh/(m²a)
SAVINGS
85 %
CO2-EMISSIONS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
125 kg/(m²a)
AFTER
15 kg/(m²a)
SAVINGS
88 %
