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Barbara CunibertiEuropean CommissionJoint Research Centrebarbara.cuniberti@ec.europa.eu | Delia D’AgostinoEuropean CommissionJoint Research Centre | Daniele PaciEuropean CommissionJoint Research Centre | Paolo ZangheriEuropean CommissionJoint Research Centre |
1) According
to EPBD recast, after 2020 all new buildings are expected to be nearly-zero
energy buildings but, as known, the largest energy saving potential in the
building sector is represented by existing buildings. Which are the most
important actions taken by EU to incentivize retrofit actions oriented to nZEB
goals?
Since the early 1990s the European policy
framework for buildings has quickly evolved and Member States (MS) adopted a
wide array of policy measures to transpose the general principles defined by
the European Directives (EPBD, EPBD recast, RED, EED).
However, it is still valid the
consideration made by the Commission in the 2010 proposal for revision of EPBD:
“the sector has significant untapped potential for cost-effective
energy savings”. In fact, the (few) estimations available assess the
European renovation rates between 0.5% and 2.5% of the building stock per year,
and a minor part of these is represented by deep and nZEB renovations.
The economic crisis of last years did not
help to push toward the desired paradigmatic revolution, and on the contrary it
accentuated the importance of financial barriers. Not surprisingly, then the
policies designed by national and local authorities focused mostly on this
aspect. Since 2008 almost all Member States introduced or strengthened their
incentive measures, encouraging cost-effective energy renovations. Generally,
the main target is the deep refurbishment of residential buildings, but also specific
instruments for the tertiary and public sectors have been implemented.
We are telling successful stories since
long time. The time needed to convince all cultures and stakeholders composing
the European Union that a strong engagement on the energy efficiency of our
buildings is crucial and necessary. The quick evolution of the national
legislations towards nZEBs is a good and promising signal, but a wide diffusion
and application will depend crucially on the involvement of all stakeholders
from local government, industry, financial institutions and civil society.
2) Which
are instead possible obstacles to a large-scale dissemination of retrofit
interventions towards nZEBs?
We see different kinds of obstacles. We
would mention here the main three:
- Financial barriers:
the cost of existing solutions is still high (considering the average age or
the EU building stock reaching nZEB level it usually means deep, structural
refurbishment) and building owners usually do not see sufficient returns on the
investment (or not in a reasonable time). Based on these issues and on the
value of collateral (the increase in the value of the property is not always
linked to the energy renovation efforts) also banks are not currently providing
adequate financial support at individual building owners.
- Technical barriers:
technical solutions to achieve nZEBs in existing buildings are not always
feasible and cost-effective because limited by the existing building structure
and by location. Normally specific interventions on individual cases and
customized solutions are necessary, but new integrated design approaches and
innovative building processes can reduce the investment costs and the
renovation time.
- Information barriers:
still not all citizens in Europe are well informed about the availability of
energy efficiency solutions and incentive programs available in their territory.
Information, when available is still scattered and results into a wide range of
options that are difficult to compare and understand for the final user. Key
stakeholders (e.g. building administrators) and professionals should be
regularly updated (importance of continuous professional education program) about
innovative solutions and progresses in national and local policies.
3) What
are, in your opinion, the most common goals for the effective widespread
application of retrofit interventions towards nearly-zero energy projects?
Important progresses have been made during
the last years but a series of goals remain to be achieved to reach a
widespread application of nZEBs retrofit interventions
One goal would be to stimulate R&D and
competition in the building sector to find affordable, cost-effective and
flexible solutions that can be applied to a large number of buildings in
different regions.
Another key objective would be for public
administrations to provide clear and unbiased information to all stakeholders
and incentives to building owners, in all the situations where the market,
alone, fails to deliver the desired outcome in terms of nZEB refurbishment
(e.g. positive externalities, social benefits higher than private ones) or
develop and support plans for large scale deep renovation of the building stock
(e.g. phasing out of the most energy inefficient buildings etc.)
In addition, despite awareness of the
importance of energy efficiency retrofit has significantly increased in the
recent years, to further improve the diffusion of the specific concept of nZEB also
outside the policy, academic and professional circles would possibly help in
the widespread application of interventions towards nearly zero energy projects.
To achieve this goal education programs are of key importance, from primary
schools to specialized professional courses.
4) Which
should be the desirable role of public administrations in the process towards a
broader market transformation oriented to sustainability in the built
environment?
Public administrations at all levels play
various roles in this process.
On one side they should be responsible for
the energy renovation of their building stock, in compliance with European
Directives provisions (e.g. EED Art. 5). This would also be an important
indirect effect on private owners as public administrations would thus play an
exemplary role in the promotion of large-scale energy retrofit program.
On the other side, public administrations
are called to support the adoption of market-oriented solutions: to provide a
consistent and well defined legal framework, to adopt clear medium and
long-term strategies, targets definitions and measures, to remove potential
barriers to R&D, technological innovation, and competition in the
construction sector and to foster a widespread energy efficiency education and
specialized courses for professionals.
However, there would probably still be room
to public interventions aimed at financially support energy retrofit projects
or to assure adequate return expectations to investors, especially in specific
areas and for medium and low-income population.
5) Nowadays
good practices of realized high performing buildings - not nZEBs - are
available, such as for example passive houses or green buildings. To what
extent experiences of green buildings may be considered a precedent for the
evolution of nZEBs?
All past and current experiences in the
field of sustainable architecture are somehow related to the development and the
evolution of the nZEB concept. They share the overall objective of contributing
to save energy and reduce significantly the environmental footprint of
buildings. However, even if in the same line, it is worth emphasizing that
there is not a direct link between them nor nZEBs represent an evolution of
earlier established concepts of high-efficient buildings. While some of the established
solutions and principles (e.g. green building or eco-building) can be found
also under the nZEB building generation, nZEB represent something different,
which could be considered as more flexible, with a specific focus on the
integration of strong energy efficiency measures and renewable energy
generation.
Green labels and eco-certifications, such
as LEED, BREEAM, Green-Building Programme, etc., demonstrated that they can be
an important incentive in the diffusion and promotion of sustainable buildings.
In light of these experiences, one could suggest that a nZEB "certification",
based on the national definitions and standards, could be in principle equally
important in the development of the market for nZEBs. The EPBD Directive (in
article 11(9)) already requires the Commission to adopt, in consultation with
the relevant sectors, a voluntary common European Union certification scheme
for the energy performance of non-residential buildings.
6) The
lack of a harmonized tool for collecting and sharing quantitative data from
different case studies emerges nowadays; which would be instead the role and
the influence of a common database in the process of nZEBs diffusion?
The realization of deep retrofit or nZEBs
retrofit requires a wide range of technologies, systems and solutions with different
degrees of complexity and sophistication, depending on the location and environment
conditions, but also on local legislation and market conditions. A large-scale
harmonized database would provide a complete overview of the state of the art
in the different regions or MS, in order to compare and assess the most
important information on the available solutions, but also on local conditions
(legislation, market etc.), costs, benefits and financial support schemes. A EU
database would have the potential to help all stakeholders; it would increase
transparency and competition, it would reduce uncertainties for investors in
calculating risks and payback times, it could serve as a kind of European vademecum of examples which designers, administrators and
owners can consult for the most appropriate and effective solution to apply to
specific cases.
A large-scale harmonized dataset on nZEBs
refurbishment could also provide important quantitative information and
indicators to monitor and evaluate the market, consumer choices and the impact
of specific policy measures as well as to formulate specific targets for policy
interventions.
7) Which
information about nZEBs is more relevant to share?
The following information should be collected
for each building where possible:
Location: the
climatic condition of the building location is one of the most significant
factors which can influence the nZEB design and its technical equipment, also
regarding renewable sources available on site.
Year of construction: permits not only common classification in the timeframe but also the
analysis of the time needed in the countries to implement EU or local policies.
Geometrical data: as area in m² and/or number of floors.
Envelope typology: information about the building envelope should be given as: U
value W/m²K for roof, basement,
external walls and windows.
Technical equipment: type of technology should be specified for heating, cooling and
ventilation system, as well as lighting and control system. Sub-categories for
each sector could be detailed, in order to simplify statistical analysis. For example,
sub-categories for heating could be: district heating, heat pumps, condensing
boilers, etc.
Renewable sources technology and % of RES
(energy level): as the EPBD defines a nearly
Zero-Energy Building as "a building that has a very high energy
performance… nearly zero or very low amount of energy required should to a very
significant extent be covered by energy from renewable sources, including
renewable energy produced on-site or nearby", knowing the %, the type of
renewable sources (share of renewables in a quantitative or qualitative way)
and the technology employed can give the measure of the understanding and
implementing of the EU Directive in the different MS.
Energy demand [kWh/m²y]: energy is one of the main indicators. The value can be expressed
through a model or referring to a building reference standard.
Investment costs, financial incentive and
discounted payback time period (yr): economical
and financial information should be given; investment costs can be given ineuro
or euro/m²; financial incentives are
comprehensive of lease-back scheme, national and regional founds, loans and
findings, etc.
Reference values or standards eventually
established in the MS: if presents, labels, energy classes, standards, etc.
Socio-economic data: as type and number of occupants, age of the occupants, economic
conditions, etc. These data can be very important to analyse the type of
behaviour of the people living in the house and how they can influence the good
functioning of the efficiency measures implemented.
For retrofit interventions the data
collected should ideally allow a before and after comparison of the building
energy performance.
8) Which
is in your opinion the right approach to disseminate and to replicate retrofit
actions on the building market?
The most common approach to replicate
retrofit actions in the building market is to establish a number of successful
representative projects across Europe, in a number of representative locations,
in order to show how projects can succeed in very different climates and
overcome other specific building related challenges. These include:
·
Different construction
techniques for walls and other components.
·
Different heating
systems - for instance natural gas based systems in some
locations against all -electric designs in others.
·
The output of representative photovoltaic
systems in different climates in EU locations and how these
loads vary with building thermal and electrical loads.
Testimony from homeowners would certainly help
to disseminate information on the success of the project. Finally, at least for
high visibility initial projects, it would be important to have them monitored (e.g.
with utility records compared before and after retrofit interventions) including
also internal temperature and comfort conditions to help validate the nZEB
retrofit approach. Also, to the extent possible, the real costs of
refurbishment should be tracked (including also the often neglected
"intangible" costs) and in this way the relative benefits from energy
savings may be compared to the realistic costs of the remodelling effort.
However, to significantly improve the dissemination
of successful retrofits two other factors are considered of key importance:
a) The development and use of information tools,
in order to collect and share case studies data and experiences. An open data
web-based platform together with social media and crowd-source datasets would
have a great potential to spread good practices, technical solutions,
experiences, information on costs and benefits, policies and incentives programmes,
educational initiatives.
b) The development and diffusions of large-scale education and information
programs targeted at all level from children
to elderly, from professionals to non-professionals and policy makers.
9) Which
are the most important technologies to be developed to reach nZEB targets?
Technologies to reach nZEB include both the
efficiency and renewable generation sides. Integrated and staged technologies
to be implemented are challenging tools towards the nZEBs diffusion in Europe.
Among the most important technologies are:
·
Lower cost high-efficiency Heat
Recovery Ventilators (HRV) and Energy Recovery
Ventilators (ERV) for ventilation air. Analysis
shows that air tightness is important in heating dominated climates; with air
tightness comes a need to provide sufficient ventilation airflows with heat
and/or enthalpy recovery.
·
Advanced smart
window systems with automated shutters or window coatings that
allow adjustment to building interior conditions.
·
More compact high
performance insulation for piping. This may include low cost
Aerogel type materials with very low thermal conductance which can substantially
reduce thermal losses from piping either with radiators or otherwise with solar
combisystems.
·
Cooking and range hood
ventilation represents a special challenge, not only because it
is not often done in the most air tight building designs, but also for indoor
air quality issues.
·
Improved heat
pumps for heating and cooling: this includes both air source
heat pumps used for heating and cooling in mild climates and in geothermal
systems for heating in colder locations where electricity is used for heating. Higher
system COPs are desirable in both equipment classes. Electric heat pump water
heaters in mild Mediterranean climates will be useful to obtain supply and
exhaust air from the outdoors, or during the cooling season, to provide their
supply air as a source of free cooling for the building interior.
·
Continuation of progress on appliance
efficiency and lighting.
·
Diffusion of precast
elements to be easily adapted to the building type with the
support of specific innovative tools able to decrease the price of industrial
processes.
·
Higher PV module efficiencies. The current poly-crystalline silicon systems have efficiencies in
the 14-16% range commonly. Performance in the 20%+ range is desirable as this
will allow greater rooftop generation at lower installed costs. Currently, the
available roof space often limits how much PV electricity can be generated
onsite. Higher module efficiencies would increase the potential power
production while reducing the cost of installation labour by reducing the size
and numbers of PV modules necessary for greater solar electric production.
·
Electric storage: producing power while improving the match with the utility grid
will necessitate increasing onsite electrical storage to help flatten out the
load curve and to smooth out the household electrical demand to be as close to zero
as possible over the daily - and eventually - over the weekly cycle. Such needs
will then require 10-20 kWh of electrical storage at the lowest possible cost.
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