44
AR 2016.1 Ljubljana
sustAinAble desiGn OF enerGY eFFicient FAMilY hOuses
trAJnOstnA zAsnOvA enerGiJskO uČinkOvitih 
enOdruŽinskih hiš 
In the last twenty years, saving energy 
has been prioritized in all segments 
of  its consumption. The primary 
goal of  energy savings, especially 
the energy coming from non-
renewable resources, is not only to 
reduce consumption due to limited 
availability of  natural resources, but 
also for reasons of  environmental 
protection. Consuming and 
processing energy coming from 
non-renewable sources leads to 
carbon emission and release of  other 
toxic and dangerous substances into 
the environment, which results with 
many changes in the climate and life 
on Earth in general. 
According to the European Union, 
the average energy consumption in 
buildings makes up over one-third 
of  all energy use. That is the reason 
numerous laws and regulations in the 
EU member states have addressed 
the need to limit energy use in 
buildings. 
Reducing energy demands in buildings 
can be achieved by increasing 
energy efficiency, which entails 
lower use of  energy in the process 
of  construction, heating, cooling, 
air-conditioning, water heating and 
lighting while maintaining the same 
level of  comfort and pleasure of  
living or working in the buildings.
These requirements have made it 
customary to design buildings in 
which energy use is significantly 
reduced. Minimum energy efficiency 
standards have been prescribed by 
regulations while the actual degree 
of  energy efficiency is in the cases 
of  individual buildings determined 
by investors who have increasingly 
become familiar with the quality of  
life in buildings whose construction 
respected both energy efficiency 
requirements and the general 
awareness of  possible threat to 
environment posed by irrational 
energy consumption.
Miha Praznik, 
Martina Zbašnik-Senegačnik
Trajnostna zasnova energijsko učinkovitih enodružinskih hiš
Ljubljana: UL Fakulteta za arhitekturo, 2016
ISBN 978-961-6823-77-7 
Recenzija / Review
Dr. Zoran Veršić:
AR 2016.1Sustainable design of energy efficient family houses. Recenzija
45
Early solutions for achieving energy 
efficiency of  buildings were focused 
on improving thermal protection 
of  the building envelope through 
increased thermal insulation and high 
insulation-performance windows 
and doors. The next step was the 
construction of  airtight building 
envelope and efforts to reduce 
thermal bridges. These architectural 
and structural measures, energy 
efficiency requirements were directed 
at increasing efficiency of  heating and 
cooling systems, decreasing energy 
loss through ventilation of  heated 
spaces in buildings (installation 
of  highly efficient waste air heat 
recovery systems) and saving energy 
needed for the preparation of  hot 
water and lighting. All these measures 
have indeed led to increased energy 
efficiency or reduction of  energy 
demand associated with the use of  
buildings. 
However, energy consumption is not 
only related to daily usage since the 
lifespan of  buildings entails stages 
ranging from their construction, to use 
and, finally to their deconstruction. 
Energy consumption in buildings 
starts from the use of  resources for 
the production of  building materials 
and their processing, transport and 
use in the construction process 
and maintenance, and it ends with 
deconstruction of  the built structures 
and the management of  dismantled 
materials.
The majority of  current requirements 
for energy efficiency is focused on the 
energy consumed in the course of  the 
use of  a building while it neglects to 
take into account the energy used in 
other stages of  a building’s life. Various 
building materials are characterized 
by specific energy requirements and 
the related environmental impact. 
Building material industry is a 
significant energy consumer and 
causes carbon emissions and other 
types of  environmental pollution. 
Energy consumption in buildings over 
their lifetime represents the biggest 
part of  the entire amount of  energy 
used in all stages of  the buildings’ 
lives. Increasing energy efficiency 
implies a further increase in the use 
of  building materials and products, 
which raises the level of  energy 
consumption for the production of  
building materials and equipment. 
This dependent relationship means 
that the reduction of  energy demand 
for the use of  a building does not 
lead to the reduction of  the total 
amount of  primary energy used over 
a building’s lifespan. 
The first section of  the book gives 
a detailed analysis of  a building 
technology and thermal system used 
for the building envelope, and the 
consequent environmental impact 
caused by the production of  materials 
that can achieve higher energy 
efficiency.
In the second section, the authors, 
well experienced in designing energy-
efficient buildings, give their take on 
the topic of  design and selection of  
qualitative parameters for achieving 
high energy efficiency based on 
an analysis of  existing energy-
efficient structures. Designing 
highly energy-efficient buildings is 
an interdisciplinary endeavour that 
inevitably links architectural design 
of  the building envelope to the 
engineering part of  work related to 
installations. It also entails testing the 
impact of  individual plans on the final 
result during all phases of  the design 
process. For that reason architects 
need to know the basic rules which 
can result in design plans for energy-
efficient and cost-effective houses. 
Verification of  energy efficiency in 
buildings is based on an analysis of  
different models and parameters 
which impact energy efficiency. It 
is therefore important to determine 
these parameters and how they can be 
most efficiently used in the search for 
most suitable design solutions. 
The book gives results of  the 
analysis that has been conducted on 
a sample of  over hundred energy-
efficient family houses in Slovenia. 
By interrelating individual parameters 
and analysing their impact on the result 
and the achieved energy efficiency it 
was possible to present optimisation 
procedures for achieving energy 
efficiency of  family houses.
The book also shows results obtained 
through measuring energy parameters 
in the case of  energy-efficient 
residential buildings, and results 
of  a survey conducted on dozens 
of  energy-efficient buildings in 
Slovenia. These results and previously 
determined parameters affecting 
energy efficiency formed a basis 
for guidelines which are crucial for 
individual segments that constitute 
the concept of  energy efficiency of  
buildings as well as for determining 
engineering properties of  installation 
systems.
The readers can find in the book 
around ten very good examples of  
passive and low-energy consumption 
houses in Slovenia with fundamental 
information on the houses, their 
energy performance, building 
technology and materials, HVAC 
systems, as well as illustrations and 
other particularities of  each individual 
house. 
”Sustainable design of  energy efficient 
family houses” by Dr. Miha Praznik, 
a mechanical engineer, and Prof. 
Dr. Martina Zbašnik-Senegačnik, an 
architect, is a well-structured book, 
written in clear and understandable 
language and it contains numerous 
illustrations and graphs that further 
explain the topic. The book gives 
a detailed and systematic account 
of  a new approach to design and 
construction of  energy-efficient 
buildings with special emphasis on 
family houses. The presented topics 
form a basis for a new design process 
of  highly energy-efficient buildings 
that takes into consideration the key 
parameters and indicators for a holistic 
evaluation of  energy efficiency. As 
such, they also represent an original 
scientific contribution.
This book could only have been 
written by authors with abundant 
experience in design of  energy-
efficient buildings. Their professions 
supplement each other and form a 
common goal by which they have 
shown an inevitable link between 
architecture and engineering systems 
in finding solutions for energy 
efficiency requirements for buildings. 
The authors’ scientific and 
professional work resulted in 
numerous remarkable papers and 
projects in this field that stand out 
from typical architectural solutions. 
The book is intended for professionals 
and scientists whose main interest is 
energy efficiency of  buildings and 
it builds upon the previous research 
and knowledge on the same topic. 
Furthermore, it lays the groundwork 
for future research and practice and 
can be greatly helpful in analysis and 
design of  new highly energy-efficient 
buildings.