KoPro Lzk+ - Cost and process optimization in the life cycle of nearly zero energy buildings

Starting point/Motivation

As research and demonstration projects prove, it is possible to realize cost optimal nearly-zero and plus-energy buildings. While realized buildings have clearly shown that nearly-zero energy targets can be achieved using existing technologies and practices, most experts agree that a broad scale shift towards nearly-zero energy buildings require significant adjustments to prevailing processes and methods in a buildings lifecycle. The widespread market uptake is expanding very slowly, since methods and processes for the cost-effective integration of efficiency measures and renewable energies are lacking. A broad scale shift towards nearly-zero energy buildings requires additional methodical approaches and processes trough all stages of the project life cycle.

Contents and Objectives

The project focuses on proven and new approaches for the cost reduction of nearly zero energy buildings enabling a continuous energetic-economic optimization of highly efficient buildings in all planning phases.

Methods

The main goal is to identify the extra-costs for nZEBs and to promote innovative approaches taking into account the cost-effectiveness for all the Stakeholders. Based on realized zero and plus energy buildings relevant cost parameters are collected and quantified and will result in benchmarks and idealized processes. The goal was to develop a continuous methodological approach with the aim of an improved cost efficiency which will be applicable to the all phases of a buildings life cycle.

Results

The additional costs of measures for nearly zero and plus energy buildings are so insignificant that highly efficient buildings cause the lowest costs in their life cycle. This statement can now be confirmed with the present study of seven example buildings with different forms of use, as well as new construction and renovation. Energy efficiency measures have only a small percentage influence on construction costs, but can save many times more CO2 emissions. Seen over the utilization phase, these efficiency measures are then usually cost-neutral or even economical. The following can be summarized:

• The energy level has a small influence on the building and construction costs. Energy efficiency is therefore not a major cost driver in construction.
• The additional structural costs of energy-efficient variants are compensated in the life cycle of most technologies even without subsidies.
• The cost optimum of primary energy demand and CO2 emissions is in the range of passive houses. Passive house envelopes and highly efficient windows are usually economical even without subsidies. This is also due to the long lifetimes of these components compared to building services.
• The cost optimum of CO2 emissions is very flat. Low emissions and energy requirements can therefore be achieved with different energy concepts as long as the building envelope is very efficient. This means creative and conceptual flexibility.
• It is shown that energy efficiency and economic efficiency are not opposing strategies, but can complement each other very well. The selection of variants according to life cycle costs is therefore sensible and should increasingly be used as a decision-making or funding criterion.
• Interactive planning catalogue available online

Project management

AEE INTEC

Project or cooperation partners

Energieinstitut Vorarlberg

AEE INTEC
DI Tobias Weiß
Feldgasse 19
A-8200 Gleisdorf
Tel.: +43 (03112) 5886
E-Mail: T.weiss@aee.at
Web: www.aee-intec.at