Exemplary Buildings to nZEB

Exemplary Buildings, a step towards nZEB (nearly
Zero-Energy Buildings) in the energy policy of the
Brussels Region
Virginie LECLERCQ, Brussels Institute for the Management of Energy and the
Environment, Energy Director, and WILLEM Pierre, ecoRce sprl
The Brussels Context
The energy policy of the Brussels-Capital Region, initiated in 2004, has been developed
from isolated experiences as a coordinated and ambitious policy in the sustainable
construction sector, imposing nearly zero-energy building requirements on all new
constructions as of 2015. The Region has fulfilled these requirements using various
measures and it will continue to support and expand this objective within the framework of
the European policy planned for 2020 and 2050.
Numerous items of information, awareness-raising campaigns and financial incentives have
led to the development of an initial energy and climate culture.
In 2007, the Brussels-Capital Region launched, among other projects, a major programme
to facilitate the construction and renovation of buildings with very high levels of energy and
environmental performance: the “Exemplary Buildings” call for projects. This programme is
a major driving force in the construction and renovation of buildings with very high levels of
energy and environmental performance. Based on this evidence, the Region has been able
to negotiate with the construction sector and to include in its legislation the obligation to
comply with nearly zero-energy requirements for 2015.
Many measures have been implemented to support the sustainable construction sector.
Among other things, the Region has implemented a major training programme for
architects, engineers, developers, project managers, energy managers, etc. (800
participants and 15 000 hours of training a year as of 2012) and negotiated (2010-2012)
and implemented (2011-2014) an Employment-Environment Alliance for the sustainable
construction sector in order to stimulate the sector and adapt the knowledge and expertise
of the workers.
Since 2007, due to the many campaigns and projects implemented in the Region, 500 000
m² of new buildings with passive standards have already been built, are being built or are
"Exemplary Buildings"
The call
Since 2007, the Brussels-Capital Region has been organising calls for
projects with the aim of developing and facilitating the construction or
renovation of "Exemplary Buildings". Their aim is to demonstrate that it is
possible to achieve very high levels of energy and environmental
performance within a reasonable budget.
An exemplary building is a building that meets a certain number of criteria:
 Energy: the project must seek to minimise primary energy needs and the use of
conventional energy sources (fuel oil, gas, electricity) and move towards a zero-carbon
building (no CO2 emissions). The passive standard is the main objective for new
 Eco-construction: the project must include measures for limiting the building's impact
on people and their environment in terms of water management (tank, green roofing),
comfort, health and safety (type of finish), waste management, materials, etc.
 Profitability and replication: existing techniques and innovative solutions must be
combined in an ambitious project, but one that is always technically and financially
accessible to the Brussels market.
 Architectural quality and visibility: the project's visibility, its integration in public
spaces and its architectural quality (particularly in terms of home comforts, aesthetics
and the carefully designed use of materials) are also evaluated.
Calls for projects are open to all owners carrying out construction or renovation work in
Brussels: private individuals, public authorities, semi-public institutions and private
enterprises (property developers, companies, non-profit-making organisations, etc).
The buildings targeted by the call for projects must be located in the Brussels-Capital region
and have as their main purpose one of the following:
single-family dwelling ;
collective housing ;
community facilities (school, hospital, child-care facility, sports hall, etc.);
office, commercial or industrial building.
It may be a new construction, a reconstruction, renovation, extension or a combination of
these. Given the diversity of potential uses, this may entail both small (approximately 120
m²) and large construction projects (approximately 10 000m² or even more) .
The amount of the premium is €100/m² split between the owner (€90/m²) and the design
team (€10/m²).
For further information, visit www.bruxellesenvironnement.be.
Multi-residential Buildings
It is important to clarify that passive design in Belgium is unit by unit and not across the
whole building. A PHPP must therefore be encoded for each apartment.
Through the experiences of the site design team (owner, architect, engineer, contractors),
the various solutions implemented will be described in context with their main advantages
and disadvantages. It is important to note that the cases of apartment buildings summarised
below are buildings that have been completed and are currently in use.
"L’Espoir" http://app.bruxellesenvironnement.be/batex_search/Docs/fs_060_FR.pdf
Design Engineering
Project Details
Rue Fin 3-13, 1080 Molenbeek-Saint-Jean
Fonds du Logement RBC
Damien Carnoy Architectes/Dardenne David
Damien Carnoy, MK Engineering, Luc Delvaux
Key Figures
Average U
0.26 W/m².K
0.6 vol/h
1 833m²
1 150
End of 2009
Project involving 14 passive dwellings as
part of social cooperation. These
apartments are duplex apartments laid out
over 4 storeys. 7 modules are therefore
planned, which heavily restrict the common
areas and, what is more, have no lift.
Common areas containing a maximum of
two units create airtightness. The adjacent units have also been pressurised during testing
in order to limit air flows to these units. Each apartment has its own ventilation unit.
The entire building has a timber frame with particular attention being paid to acoustic
comfort throughout. It should also be noted that architectural sun protection systems have
been provided to allow plants to grow there.
"Midi-suède" http://app.bruxellesenvironnement.be/batex_search/Docs/fs_034_FR.pdf
Project Details
Design Engineering
Average U
0.14 W/m².K
Rue de Suède 24-36, 1060 Saint-Gilles
Urban Platform
Matriche, Concept Control, Amart, Daidalos Peutz, BPC
Key Figures
n50 Surface area
4 152m²
1 180
This is a project involving 30 passive apartments close
to the Gare du Midi railway station in a public-private
The architectural approach here has been to operate
as two clusters containing the common areas, each
with a lift and service shafts. Two volumes have
therefore been tested for airtightness, a particular
device having been used to ensure the lifts are airtight in compliance with current legislation in Brussels. Since the street orientation is not the
best (east-west facing), “bow windows” catch the light to the south. What is more,
fluorescent green sun protection systems also add a special style to the project.
The whole structure is made entirely of concrete; the surfaces where heat loss occurs are of
a timber frame construction. Ventilation has been centralised for both modules and all the
air is distributed through the common areas.
"RSM" http://app.bruxellesenvironnement.be/batex_search/Docs/fs_099_FR.pdf
Project Details
Design Engineering
Rue Royale-Sainte-Marie 237, 1030 Schaerbeek
Mme Elisabeth Kervyn de Lettenhove
Mr Philippe Abel
Matriche, Econergy, SEI
Key Figures
Average U
0.28 W/m².K
1 062
Renovation of a listed building into 2 very low-energy dwellings
and 1 passive dwelling. The owner owned only the top three
storeys. Airtightness therefore operates by unit. Since the
frontage is listed and the frames have to be preserved, the
energy standard achieved for these units was "very low energy".
Since the top storey has been entirely reconstructed and despite
being less compact, the passive standard has been achieved.
Each unit has its own ventilation system and all the technical
systems are located in the cellar (heat pump connected to the
solar panels). Since the existing building is a solid construction,
the frontage has been insulated from the inside while a render
on top of insulation has been applied to the rear.
It should also be noted that the
choice of materials used has been
guided by their environmental impact,
clay and fibreboard being the
materials of preference.
The main conclusion concerns the time at which these technical aspects of the building are
considered in the design process. In fact, these technical aspects need to be taken into
account from the very beginning of the design process in order to be most effective.
We can also see that the construction sector is responding positively to the Region's new
requirements despite a difficult start and entrenched attitudes to change. It is adapting and
finding alternative solutions to the problems created by increasingly demanding criteria.
What next?
As a result of the 5 calls for projects launched between 2007 and 2012, 193 projects, both
small and large, have been selected and represent a total of 520 000m². These projects will
be completed by 2016 at the latest with financial support from the Region of 29 million
In 2007, the Brussels Region did not yet have any passive buildings. As a result of the calls
for projects, the surface area of passive exemplary buildings in Brussels is set to reach 250
000m² by 2016.
Keeping going in this direction
It is essential to ensure that current policies are evolving in the right direction, to take action
against any possible abuses, to communicate the results and put forward any necessary
measures for improvement. Preliminary results show a 10% reduction in energy
consumption between 2004 and 2010 (in a constant climate), which is encouraging
evidence for the Brussels energy policy. The Brussels energy policy was rewarded with a
European Energy Award by the European Commission in 2012 and is now internationally
recognised as one of the main front runners in the implementation of nZEB. As such,
Brussels-Capital Region is an active partner in the new EU-funded PassREg project.
Brussels has shown that an ambitious energy-efficiency policy applied to the building sector
is indeed possible with good results in energy consumption over a relatively short period,
meeting the objectives and measures of the associated European policy.
With its avant-garde policy, the Brussels-Capital Region has opened the way to greater
restraint in terms of energy in its buildings without compromising its economic viability and
by giving particular attention to the most vulnerable among Brussels' population.
Brussels Environment, www.ibgebim.be, (2012)