Client:
Roland Beckedorf
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Weidestrasse, Hanover
Description
Extensive modernization work made this object into a showcase home: The exterior walls were provided with a thermal insulation system of 22 cm thick mineral wool insulation. The former window mix belongs to the past: In the new offices with floor-to-ceiling triple glazed windows, a enjoyable working atmosphere was created. The roof has been doubled to 30 cm height and staticly reinforced, the interstices were blown out with cellulose insulation. On the upper side, a 5 cm thick softboard was applied. Each a comfort ventilation system with heat recovery provides fresh air in ground and first floor.
The existing heating system is now used for providing space heating for all three residential units and covering hot water needs. The possibility of fitting a solar heat system subsequently is already available.
Two years past moving in, architect and client Roland Beckedorf decided to use renewable energies: on the roof, a photovoltaic power plant which covers the buildings annual electricity consumption, was installed.
Involved parties
Design:
architectual office (21+), Dipl.-Ing. architect Roland Beckedorf
Building data
Building type:
Apartment house
Location:
Hanover-Limmer
Year of construction:
1876
Modernization:
2007
Residential units:
1 on the first floor; architectural office as well as natural hair and beauty business on ground floor
Heated usable space:
266 m2
Subsidies:
KfW, proKlima
Initial condition
EXTERIOIR WALLS:
ca. 30 cm single skin brickwork, HTC ? 2.1 W / (m2K)
WINDOWS:
Mix of wooden and plastic windows with insulating glazing, HTC = 2,0 W/(m2K)
ROOF:
uninsulated rafter roof, HTC = 4,1 W/(m2K)
BASEMENT CEILING:
Concrete slab plate with 4 cm polystyrene insulation and screed, HTC ? 0.8 W / (m2K)
VENTILATION:
Window ventilation, as well as typical old building joints and cracks
HEATING:
Coal-individual stoves and 5-year-old gas boiler, electric instantaneous water heater for hot water
Modernization in detail
EXTERIOR WALLS:
22 cm heat insulation system made of mineral wool, quality of 0,040 W/(mK), HTC = 0,15 W/(m2K)
WINDOWS:
new wooden windows with 3-pane glazing and glass spacers made of plastic, HTC = 0.8 W / (m2K)
ROOF:
Doubling and structural reinforcement of the existing rafters, installation of overall 30 cm cellulose insulation; topside 5 cm softboard, thereafter concrete tiles on the substructure, HTC = 0.13 W / (m2K)
BASEMENT CEILING:
new floor construction on existing floating floor with 4 cm insulation: wood construction with 18 cm mineral wool insulation, quality of 0.035 W / (mK), thereafter dry screed with tiles or wood planks, HTC = 0.17 W / (m2K)
VENTILATION:
each a comfort ventilation with heat recovery and summer bypass on the ground floor and in the attic
HEATING:
Continued use of existing gas-fired boiler for space and water heating in all three residential units
AIR CONDITIONING:
no active air conditioning installed
Measured values
AIRTIGHTNESS:
n50 = 0,82 h-1
Calculated values
HEATING ENERGY NEEDS:
BEFORE
320 kWh/(m²a)
AFTER
27 kWh/(m²a)
SAVINGS
92 %
TOTAL ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
Coal
284 kWh/(m²a)
Gas
128 kWh/(m²a)
Electricity
36 kWh/(m²a)
AFTER
Gas
48 kWh/(m²a)
Electricity
19 kWh/(m²a)
TOTAL GENERATED ENERGY (AFTER):
PV System
Electricity
5.150 kWh/(a)
PRIMARY ENERGY NEEDS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
541 kWh/(m²a)
AFTER
53 kWh/(m²a)
SAVINGS
90 %
CO2-EMISSIONS FOR HEATING,AIR CONDITIONING,DHW,ELECTRICITY:
BEFORE
178 kg/(m²a)
AFTER
11 kg/(m²a)
SAVINGS
94 %
