D e s i g n I s s u e s f o r N e t Z e r o – E n e r g y B u i l d i n g s
37
DESIGN ISSUES FOR NET ZERO-ENERGY BUILDINGS
Laura Aelenei
1
, Daniel Aelenei
2
, Helder Gonçalves
1
, Roberto Lollini
3
, Eike Musall
4
,
Alessandra Scognamiglio
5
, Eduard Cubi
6
, Massa Noguchi
7
1
National Energy and Geology Laboratory, Lisbon, Portugal
2
Faculty of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
3
Institute for Renewable Energy of EURAC research, Bolzano, Italy
4
Bergische Universität Wuppertal, Wuppertal, Germany
5
ENEA CR Portici P.le E. Fermi, Napoli, Italy
6
IREC- Institut de Recerca en Energia de Catalunya, Barcelona, Spain
7
MEARU, Mackintosh School of Architecture, Glasgow, United Kingdom
Abstract
Net Zero-Energy Buildings (NZEBs) have received increased attention in recent years as
a result of constant concerns for energy supply constraints, decreasing energy
resources, increasing energy costs and rising impact of greenhouse gases on world
climate. Promoting whole, building strategies that employ passive measures with energy
efficient systems and technologies using renewable energy, became a European political
strategy since the publication of the Energy Performance of Buildings Directive recast in
May 2010 by the European Parliament and Council. Designing successful NZEBs
however, represents a challenge since the definitions are yet generic assessment
method and monitoring approach are under development and the literature is relatively
scarce about the best sets of solutions for different typologies and climates likely to
deliver an actual and reliable performance in terms of energy balance (consumed vs
generated) on a cost-effective basis. Beside this, the lessons learned from already built
NZEBs examples are relatively scarce. The authors of this paper, who are participants in
the IEA SHC Task 40-ECBCS Annex 52, “Towards Net Zero Energy Solar Buildings”,
are willing to share insights from on-going research work on some best practice leading
NZEBs residential buildings. Although there is no standard approach for designing a Net
Zero-Energy Building (there are many different possible combinations of passive and
efficient active measures, utility equipment and on-site energy generation technologies
able to achieve the net-zero energy performance), a close examination of the chosen
strategies and the relative performance indicators of the selected case studies reveal
that it is possible to achieve zero-energy performance using well known strategies
adjusted accordingly to balance climate driven-demand for space heating/cooling,
lighting, ventilation and others energy uses with climate-driven supply from renewable
energy resources.
Keywords:
zero energy building, residential building, passive measures, energy
efficiency, renewable energy generation.
Introduction
Zero-energy buildings have gained more attention since the publication in 2010 of the
EPBD recast (EPBD 2010). According to Directive, by 31 December 2020, all new
buildings should meet higher levels of performance than before by exploring more the
alternative energy supply systems available locally on a cost-efficiency basis and without
compromising the comfort in order to ensure that they are nearly zero-energy buildings.
A “nearly zero-energy building” refers to a high energy performance building of which
annual primary energy consumption is covered to a very significant extent by energy
from renewable sources, including energy from renewable sources produced on-site or
