Low Cost Low Energy
House
Sušice
PROJECT TEAM & PARTNERS
SEVEn - The Energy Efficiency Center
Charles University Environment Centre
Total Budget - 12 million CZK,
DESCRIPTION OF THE PROJECT
The Low Cost Low Energy House project focused on a design and construction of residential buildings which should use considerably less energy for heating without increasing investment costs above those of normal new housing. The construction of a house in the Sušice town was a result of a series of discussions between stakeholders, seminars and excursions. An expert team was chosen to compile a detailed target project of the low costs and low energy consuming dwelling houses in the Sušice town (other two teams have setup similar proposals for the locations in Humpolec and Železný Brod towns).
In addition to
construction of actual demonstration apartment blocks, part of the
project included other activities focused on analysis of available
financial sources, verification of standards valid in this area and
also promotion of education. Linking up with these activities,
working seminars with participation of Czech and foreign
specialists have been continuously organized.
The project's core idea was not only defining repeatable principles and building one demonstration house but, primarily, creating an environment which allows implementation of similar buildings in the future without the need for special subsidies.
The main idea of the project was to envelop the heated space with unheated space. Subordinate to the simple shape of the building with an optimum ratio between internal volume and external surface, is the outside placement of vertical routes. At the same time, half-closed galleries form the building's protection against direct effects of wind. Residential units are located in the layout centre and protected from the south by loggias enclosed with simple, partially openable glazing. The purpose of their full closure by a glazing layer is passive utilization of solar energy to reduce the temperature gradient of the external enclosing wall as well as to reduce convention around the outer wall's surface.
The building is designed with a small-span transverse supporting structure. Concrete transverse bearing walls were used, bricked from blocks. Common floor structures are also designed as concrete, using filigrane panels and inlays from recycled plastic. Use of the material bearing structure is motivated by the effort to create a pleasant, stabilized indoor environment, especially in summer. Supporting structures of galleries and winter gardens are independent, separated from the thermally insulated inside space. Wide utilization of wood is presumed for these structures, as well as for the external part of the envelope.
Envelope structures are designed as sandwich-type allowing the use of relatively cheap thermal insulation on the basis of mineral fibers. Window structures are, with regard to the necessity of optimizing investment costs, minimized in such a way that sanitary requirements of transillumination of internal space are met. Windows are equipped with heat-insulating shutters, which should be used particularly to reduce thermal losses during long winter nights.
LESSONS LEARNT & APPLICABILITY IN OTHER SITUATIONS
The main environmental benefits are represented by the reduction of energy consumption for heating by about 50% of the standard newly constructed buildings, or by some two thirds to the existing building stock.
CONCLUSIONS
During the course of the project the concept of low-cost
low-energy buildings became well recognized as a realistic,
demonstrated solution by all key stakeholders and decision makers
in the Czech Republic, including architects, construction engineers
and other professionals, governmental policy makers, and investors.
The idea of low-cost low-energy buildings is now being applied not
only by the project team itself, but also by individuals not
associated directly with project implementation.
Main direct project outcomes include:
• creation of network of professionals interested in low-energy low-cost buildings, informal association of this network with existing professional organizations
• active involvement of different stakeholders in the project, including investors, business representatives and key governmental policy makers, mainly through participation in a project steering committee and access to the first-hand project information
• know-how and information dissemination through series of informative workshops, international seminars and excursions promoting international experience with low-energy buildings
• development and design of first three multiapartment low-cost low-energy buildings in Sušice, Humpolec and Železný Brod by three interdisciplinary local teams
• public architectural competition for the best design of a low-cost low-energy building
• preparation of construction and financing scheme with three local investors (municipalities in combination with private and state co-financing), actual construction of first low-cost low-energy building in Sušice
• independent development of low-cost low-energy residential buildings by architects and professionals who gained their experience with the project, construction of such buildings for private investors
• upgrade of design of several standard buildings to be built in order to meet the low-cost low-energy criteria, and construction of such buildings
• information and experience dissemination through
preparation of specialized publications, including internet and
CD-ROM presentations
first changes in governmental policy shifting its financial support
from construction of standard buildings towards low-cost low-energy
buildings (subsidy scheme of the Czech energy Agency)
All low-cost low-energy buildings developed within the project meet the project criteria and provide:
• comfortable housing with
• standard average investment costs compared with construction of similar buildings in the Czech Republic, specific investment costs according to the apartment and building size are between 13-16 000 CZK/m2 of usable area, ie. 370-460 USD/m2
• energy consumption for space heating is lower than 50 kWh/ m2, year, ie. about 50% of the standard newly constructed buildings, and less than a third compared to the existing building stock.
The apartment house in a suburb of Sušice was approved at the beginning of 2003. In the winter and spring of 2003 nine flats were handed over to their tenants, so the results of measuring energy consumption for heating for the proportional part of 2003 and the year 2004 are now available.
The results achieved are even better than those presumed in the construction project. Real energy consumption for heating totalled 42 kWh/m2, whereas the project documents stated 55 kWh/m2. Heating costs (excluding heating-up of water) are approximately CZK 5,000 for a heating season.
However, in view of correct use of flats, it must be pointed out that it is necessary to instruct their tenants as regards handling air-conditioning units providing controlled ventilation of flats. Controlled ventilation ensures air exchange in flats while preserving thermal comfort, but its insufficient use can result in condensation of air humidity in room corners. Another low-energy low-cost apartment house has been put into operation already also in Železný Brod, where at the moment real consumption of energy for heating is also being measured and compared with the planned consumption.
CONTACT DETAILS
Seven, Energy efficiency Centre
Tel/Fax: +420 224 252 115
