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Lahwiesen, Hanover

Description

Good planning by the architect and the almost perfect coordination with all involved shareholders made it possible to keep the impacts of building work reasonable.

In order to achieve the ambitioned aim of deceeding the energys saving regulation of 2007 by 30%, exterior walls, roof and basement ceiling were valuable insulated: the 36 cm thick exterior walls bricket with a heat insulation system consisting of 20 cm thick polystyrene insulation, the roof with additional 10 cm mineral wool between the doubled rafters and 3,5 cm wood fiber softboard atop of the rafters. Windows and exterior doors achieved high-insulating 3-pange glazing with wood-aluminium-frame-construction. Based on sealing exterior components consequently to the existing construction and taping everything airtight, unwanted air draft is a thing of the past. The comfort ventilation system with heat recovery, which is situated on the attic floor, increases energy efficiency, because fresh air arrives preheated from heat transformers and canal systems into the rooms. The heating system is optimized and hydraulically equalized. It works efficient with a condensing gas boiler, a solar heat plant with ca. 7,5 square meters collectors area as well as a bivalent hot-water-storage.

Involved parties

Client:

Geyer family

Design:

Architectual office (21+), Dipl.-Ing. architect Roland Beckedorf

Building data

Building type:

detached single-family-home

Location:

Hanover-Bothfeld

Year of construction:

1959

Modernization:

2009

Residential units:

1

Heated usable space:

180 m2

Subsidies:

KfW, BAFA, proKlima

Initial condition

EXTERIOR WALLS:

36 cm solid, plastered masonry

WINDOWS:

Windows with double glazing and heat protection glas

ROOF:

14 cm insulation of mineral wool between rafters

BASEMENT CEILING:

uninsulated

VENTILATION:

Window ventilation, as well as typical old building joints and cracks

HEATING:

14-year-old gas heating

Modernization in detail

EXTERIOR WALLS:

Insulation of all solid exterior walls with 20 cm polystyrene insulation, quality of 0.032 W / (mK), HTC = 0.15 W / (m² K)

WINDOWS:

heat-insulating glazing windows remained, glazed windows were substituted for new passive house windows with heat-insulation triple glazing; wood-aluminum frame; glass spacers made of plastic

ROOF:

Doubling the existing rafters; 3,5 cm wood fiber softboard; new roof covering with concrete roof tiles; 10 cm additional insulation and continued use of the existing 14 cm insulation, HTC = 0.15 W / (m² K)

BASEMENT CEILING:

Insulating of basement ceiling as well as of basement walls with 8 cm polyurethane panels of quality 0.025 W / (mK)

VENTILATION:

Central comfort ventilation system with heat recovery; the air handling unit is located in a storage room on the attic floor

HEATING:

new gas-fired heating with 7,5 m2 solar heating plant for water heating

AIR CONDITIONING:

no active air conditioning