Client:
Ostland Wohnungsgenossenschaft e. G.
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Roettgerstrasse, Hanover
Description
The energetic modernization of this building with high-efficient passive house components was realized such consequently, that the passive house standard with a thermal heat demand of just 15 kWh/(m²a) was achieved. The exterior walls were awfully good insulated and thermal bridges minimized as much as possible. Valuable passive house windows ensure highest living comfort. Each apartment is provided with an own ventilation system with heat recovery functions, space heating is implemented via supply air. The old heat distribution system, which is extremely overdesigned for the new energy standard, is no longer requisite. Just the bathrooms are equipped with a single hand towel heating element for reasons of comfort.
Involved parties
Design:
lindener baukontor, Dipl.-Ing. architects, Susanne Gräser and Gerd Nord
Building data
Building type:
Apartment house
Location:
Hanover-Linden
Year of construction:
1950
Modernization:
2006 - 2007
Residential units:
10
Heated usable space:
839 m2
Subsidies:
dena, proKlima
Initial condition
EXTERIOR WALLS:
uninsulated brick-built exterior walls, in the area of the gable 6 cm thermal insulation available
WINDOWS:
some newer plastic windows with double glazing, partly single glazing
ROOF:
uninsulated rafters roof, HTC = 3,3 W/(m2K)
BASEMENT CEILING:
uninsulated concrete ceiling, HTC = 2,2 W/(m2K)
VENTILATION:
Window ventilation, as well as typical old building joints and cracks
HEATING:
joint district heating connection with the neighboring building for space heating, water heating with decentral gas and electric water heaters
Modernization in detail
EXTERIOR WALLS:
30 cm composite heat insulation system, quality 0,032 W/(mK), HTC = 0,11 W/(m2K)
WINDOWS:
new passive house windows with heat insulating 3-pane-glazing in synthetic frame and glas spacers made of plastic, HTC = 0,8 W/(m2K)
ROOF:
Sloping roof: new roof in joist-timber panel construction with 30 cm insulation of the quality 0.035 W / (mK), HTC = 0.13 W / (m2K) roof terrace at 5-15 cm slope insulation, quality of 0.035 W / (mK), and 15 cm base insulation, quality of 0.030 W / (mK), HTC = 0.14 W / (m2K)
BASEMENT CEILING:
12 cm heat insulation, quality 0,035 W/(mK), HTC = 0,19 W/(m2K)
VENTILATION:
each apartment has a single comfort ventilation system with heat recovery functions, heating coil connected to district heating
HEATING:
heating and water heating with district heat, heat distribution via ventilation system and bathroom radiators
AIR CONDITIONING:
no active air conditioning installed
Measured values
AIRTIGHTNESS:
n50 = 0,59 h-1
Calculated values
Calculation method: Passivhaus planning package; Initial values: Hannover building typology
HEATING ENERGY NEEDS:
BEFORE
180 kWh/(m²a)
AFTER
15 kWh/(m²a)
SAVINGS
92 %
TOTAL ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
District heating
212 kWh/(m²a)
Gas
14 kWh/(m²a)
Electricity
26 kWh/(m²a)
AFTER
District heat
38 kWh/(m²a)
Electricity
21 kWh/(m²a)
PRIMARY ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
167 kWh/(m²a)
AFTER
70 kWh/(m²a)
SAVINGS
58 %
CO2-EMISSIONS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
38 kg/(m²a)
AFTER
16 kg/(m²a)
SAVINGS
58 %
