Buildings with environmental quality management: Part 1: Designing multifunctional construction materials

Abstract

The quest for a sustainable built environment has resulted in dramatic changes in the process of residential construction. The new concepts of an integrated design team, building information modeling, commissioning of the building enclosure, and passive house standards have reached maturity. Global work on development of new construction materials has not changed, but their evaluation is not the same as in the past when each material was considered on its own merits. Today, we look at the performance of a building as a system and on the material as a contributor to this system. The series of white papers—a research overview in building physics undertaken in European and North American researchers—is to provide understanding of the process of design and construction for sustainable built environment that involves harmony between different aspects of the environment, society, and economy. Yet, the building physics is changing. It merges with building science in the quest of predicting building performance, it merges concepts of passive houses with solar engineering and integrates building shell with mechanical services, but is still missing an overall vision. Physics does not tell us how to integrate people with their environment. The authors propose a new term buildings with environmental quality management because the vision of the building design must be re-directed toward people. In doing so, the building physics will automatically include durability of the shell, energy efficiency, and carbon emission and aspects such as individual ventilation and indoor climate control. This article, which is part 1 of a series, deals with materials, and other issues will be discussed in following papers.

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Buildings with environmental quality management,
Part 1: Designing multifunctional construction materials
Mark Bomberg1, Marcin Furtak2 and David Yarbrough3
Abstract
The quest for a sustainable built environment has resulted in dramatic changes in the
process of residential construction. The new concept of an integrated design team,
building information modeling, commissioning of the building enclosure, and passive
house standards have reached maturity. Global work on development of new construction
materials has not changed, but their evaluation is not the same as in the past when each
material was considered on its own merits. Today, we look at the performance of a
building as a system and on the material as a contributor to this system. The series of
white papers—a research overview in building physics undertaken in European and North
American researchers—is to provide understanding of the process of design and
construction for sustainable built environment that involves harmony between different
aspects of the environment, society, and economy. Yet, the physics is changing. It merges
with building science in the quest of predicting building performance, it merges concepts of
passive houses with solar engineering and integrates building shell with mechanical
services, but is still missing an overall vision. Physics does not tell us how to integrate
people with their environment. The authors propose a new term buildings with envi -
ronmental quality management because the vision of the building design must be re -
directed toward people. In doing so, the physics will automatically include durability of the
shell, energy efficiency, and carbon emission and aspects such as individual ventila tion
and indoor climate control. This article, which is part 1 of a series, deals with mate rials,
and other issues, will be discussed in following papers.
KEYWORDS: Sustainable built environment, construction materials, building science, building
physics, material evaluation, integrated testing and modeling
1
Adj. prof. dr.,McMaster U, Hamilton, ON, Canada, honorary mem. BETEC/NIBS, Washington DC, USA
2
Prof. dr. arch. Director of Lesser Poland Energy Efficiency laboratory (MLBE), TU Cracow, Poland
3
Emeritus Prof. dr. Tennessee Tech. University, V. President R&D Services, Inc, Cookeville, TN, USA
Corresponding author: mark bomberg, e-m mark.bomberg@gmail.com

2
Introduction
A traditional title given upon completing an advanced academic work is doctor of
philosophy. This article comes as an address from two philosophers, called teachers
of building science (physics) and an architect who came to this field by different
route, but who share the need to define the final goal before starting the work.
Speaking about application of building science, we need to start with defining
some basic concepts. Leonard Bachman, in the course of Architecture at Houston
University 2013, used the following definitions: (1) Data = characteristics or prop-
erties measured on materials or systems; (2) information = an effect of the process
of transforming data into clusters on which decision process can be based; (3)
knowledge = information that is in conformance with other fields of organized data;
and (4) understanding = ability to reproduce knowledge from first principles and
apply it to the unique situations.
Using these definitions, we agree that the ultimate objective of building science
is to provide understanding of the process of design and construction for a sustain-
able built environment involves harmony between different aspects of the environ-
ment, society, and economy. A definition of sustainability involves different scales:
country, region, city, or individual building. The term balanced buildings means a
building where each of the above aspects is equally important, clarifies an under-
standing of the concept of sustainability. As we judge our research work from this
perceptive, we may as well call the following review—a philosophical discussion.
This article is the first in series of research overview papers that extrapolate from
40 years of experience in passive housing. Yet, the use of solar energy in traditional
passive house design is limited to the level to which the ventilation (natural or
mechanical) can eliminate the summer overheating. To increase the solar energy
contribution, we will use water-based heat pumps for surface heating or cooling and
by hydronic means that controls the contribution of thermal mass to the energy
balance. Furthermore, we will use moisture buffering materials to modulate indoor
relative humidity. Effectively, the first lesson from the last 40 years that is presented
in this article is that all materials used in modern house must be multifunctional and
their selection is based on how well they satisfy requirements of the walls, floor, and
roofs.
North American chaos in residential construction 1946–1990
North American buildings are conceived with a bias toward the heating season
because heating is perceived to be more expensive than cooling. Energy conserva-
tion became a keyword after the crisis in the mid-1970s but has recently achieved

Bomberg et al. 3
national recognition. Statistical data, however, reveal that typical yearly energy use
in multiple residential buildings (MURB) in 1990 in Vancouver, Canada, was 315
kWh/m2. Since 1990, energy use in those buildings steadily declined, reaching 250
kWh/m2 per year in 2002 (Finch et al., 2010). This would be fine, until we find that
the energy use rates of 2002 are identical to those of MURB built in 1929. In other
words, the uninsulated masonry buildings in the 1920s and the shiny, glass-clad
buildings of today uses the same amount of energy, despite all of the energy-saving
measures currently available. Is this because of the new facade standards and
aesthetic values are expected?
This is not a surprise to a scientist. Centuries of small improvements resulted
in massive structures responding slowly to the exterior climate. In temperate
climates, these buildings were relatively comfortable by employing simple
provisions such as high ceilings, fans, and cross ventilation. In cold climates,
heavy masonry stoves in the middle of a dwelling or radiators that worked a few
hours a day provided heating, but the thermal mass of the building served as a
“heat battery” releasing energy without using fuel, and, of course in proportion
with decreasing indoor temperature.
These buildings were airtight because both sides of exterior walls were covered
with lime-based plasters. Lime develops strength slowly, allowing settlement of
walls while maintaining adhesion and continuity and thanks to its elasticity it resists
macro-cracking and has a self-healing capability. Double-hung windows
(casements in Europe) were well integrated into the masonry and repainted every
few years with oil paint. Thermal controls were simple, with devices such as radia-
tors controlled by a manual valve and a supply of steam or hot water from boilers
resulted in indoor temperatures that varied between periods of comfort and dis-
comfort as the exterior conditions changed. The number of openings was reduced
mostly to those following the building’s function.
The unbalanced progress in North American construction
Discussion of progress requires defining the frame of reference. What clearly
would be a progress in house building industry we call retreat from the balanced
buildings perspective because economic progress was achieved without resource
optimization and without environmental considerations. No one has studied the
impact of changing aesthetic tendencies on these values.
In 1900, there were about 500 different construction products to choose from in
the Swedish market. By 1950, the number increased to about 5000 and today we
can find 55,000 to 60,000 different products.1 Growth of specialized expertise and
the fragmentation of the design process erased the capability of an architect to
control the design process. The economic effect and the need for innovative and
attractive forms that were selling the buildings took over the design process.
In Europe, moisture was not a serious consideration because masonry is resilient
to moisture and bricks exposed to freeze–thaw conditions were carefully selected.

4
The accumulation of water has been a major problem for wood frame
buildings of North America. Bomberg et al. (2015) identified 12 papers and
books printed between 1938 and 1958 that dealt with water vapor transfer and
condensation. Yet, a lucid explanation of condensation, given in 1958 finally
got the attention of code and standards bodies. Why?— at this time water
damage became evident in many buildings.
Condensation analysis was able to establish the occurrence of condensation, but it
did not predict the amount of condensate because it dealt only with one aspect of water
vapor transport and liquid (condensed) water moves by osmotic, capillary, or
gravitational forces. Bomberg et al. (2015) discussed this issue in detail to highlight
that typical construction practices did not use the building physics knowledge.
In the meantime, the architect’s fascination with large windows forced engineers
to increase the level of thermal insulation until one found that light-weight buildings
with large amounts of glass in the walls were leaky and had a multitude of
microclimates within one building. Thermostats covering large zones could not
provide adequate control. Heating slowly evolved to forced-air heating, ventilation,
air-conditioning (HVAC) systems. HVAC systems could provide summertime
cooling and dehumidification, as well as wintertime heating and humidification.
Thermostatic controls for these systems operated with tight set points. In short,
mechanical systems took over 100% of the task of climate control.
Air quality and moisture concerns in North America
The simplified version of building physics that was used by many national codes led
to stringent requirements for water vapor barriers (retarders). In Canada, for example,
vapor barriers were required to have permeance of less than 0.75 perm [45 ng/(Pa m2
s)] when measured on aged products. The emphasis on water vapor control received
a disproportionate amount of attention just because it is easy to calculate. Some
“authorities having jurisdiction” went as far as stating that no condensation was
allowed.
The change of directions was brought about by construction practice. To replace
traditional heating systems with electric baseboard heating, builders increased again
the levels of thermal insulation in the cold regions of Canada. These electrically
heated buildings, unfortunately, showed condensate on second-floor windows
(Bomberg et al., 2015). These observations led to new recommendations for air-
tightness of the ceiling construction and new partition-to-ceiling details. The linkage
between electrically heated houses and patterns of natural ventilation was now
evident.
In a parallel development, air exchange rate in houses with flue-less combustion
furnaces was found to fall below that required by codes, implying that well-insulated
houses with substantial airtightness may not provide sufficient air exchange when
built without chimneys. The 1980 Canadian National Building Code required that all
dwellings have a ventilation system capable of providing 0.5 air changes per hour
(ach)

Bomberg et al. 5
In 1990, based on the observations that these ventilation rates resulted in too-dry
air in winter, this requirement was reduced to 0.3 ach. Now the focus on indoor air
quality (IAQ) and moisture management moved from natural ventilation and vapor
barriers to mechanical ventilation and air barriers. Incidentally, air, water
(weather), and vapor barriers products gave rise to new industries.
From the building physics viewpoint, a light-weight, fully air-conditioned build-
ing eliminated all the advantages that had existed with the old masonry buildings.
To use thermal mass, one should use variable interior temperatures. Without the
contribution of thermal mass, the HVAC system must deal with peak heating and
cooling loads and the size of the system must be increased. Furthermore, zones in
large buildings were based on the assumption that interior air is static, whereas in
thermal stratification, multi-zonal air flows, and even the occupant activity, all of
these factors worked against the satisfactory operation of systems where ventilation
was combined with air-conditioning.
Finally, as the traditional HVAC systems operate on dry air temperature and
achieving comfort during cooling involves both latent and sensible loads, the whole
field of air dehumidification had to be created for the southern part of America.
Transition to low-energy housing (1990–2020)
It is difficult to find a precise time when codes and standards across the world started
a race toward near zero or net zero energy structures. Canada, in the late 1980s,
created integrated design process (IDP) teams mostly because we had no one with
experience on how to deal with design of so-called sustainable buildings. Yet, design
cost increases more when changes to the design are introduced later in the process so
moving most decisions at the front of the process proved beneficial to all parties.
The integrated, performance-based design differs from the conventional way of
design, where a building was “engineered in pieces” to objectives defined by
experts working individually in the process of design. An integrated design process
is the modern way to realize “performance architecture” that is, design with a view
to field performance. In this process, however, all members of the design team must
have some knowledge of building science.
This knowledge of building science allows them to translate the user requirements
into the measurable performance objectives that will eventually define the design
process (Table 1).
Table 1. Performance requirements as defined by Hutcheon (1953).
Control heat flow
Con trol a ir flo w
Con trol water vapor flow
Con trol rain flow
Con trol groun d water flow

6
Control light and solar radiation
Control noise and vibration
Control pollutants, odor, and vermin
Con trol f ire
Provide strength and rigidity
Be durable, resilient,a aesthetically pleasing and economical
_________________________________________
a Resilient is added to consider flooding, hurricanes and similar events
While architects continue to have an integrating role within these teams, it is
especially important for architects to understand building physics and communicate
with other experts in the design team. We have observed, however, that many
universities do not teach the principles of design and interaction between different
subsystems but treat building physics as another academic topic where equations
replace the process of functional analysis and logic of integration of different
subsystems. For this reason, we keep in North America the term building science that
was defined by late professor N.B. Hutcheon.
The imperatives of near zero energy buildings seek to address comprehensive
environmental control (thermal, moisture, and air infiltration) as formative and
integrated issue in the process of design. Such a design includes the following:
 Energy efficiency of the envelope, with understanding of interactions
between thermal, moisture, and air flows;
 Durability of materials and assemblies that have been evaluated for long-
term thermal and moisture performance aspects and includes the cost of
operation and maintenance;
 Indoor environment (IE) that includes a comprehensive approach to envi-
ronmental control addressing all parameters of thermal comfort and air
quality.
In the past, environmental control involved only mechanical engineers. Today,
large, advanced buildings use ventilation interacting with heating, cooling, humidity
control, and even air purification. These strategies, however, should be scaled and
applied for any size of buildings. All of the people in a design team must understand
how combined action of HVAC and building enclosure shapes the IE. By
identification of competence, we have defined a core of the design team: (1) civil
engineer, (2) mechanical engineer, (3) building scientist capable of hygrothermal and
energy modeling, (4) construction cost estimator, and (5) an architect as a formal
leader together represent a core of the integrated design team.
What are we missing in this transition?
Energy modeling has been preoccupied with mechanical systems for heating, cool-
ing, and ventilation while neglecting their interaction with building enclosures. To
produce correct results, hygrothermal models must be added to the modeling effort.

Bomberg et al. 7
These models, however, must deal with real-time solutions and not only with
comparative simulations. We need to improve current hygrothermal models that
were originally developed for parametric study so that they may be used for real-
time modeling of the interacting transport phenomena. The improved hygrothermal
models must include information on air leakage through the walls and estimate the
impact of air and moisture transport on energy.
Moisture buffering can not only modulate indoor relative humidity but also
reduce peak energy loads. Uncontrolled relative humidity affects both IAQ and
durability of building materials. Expansion of hygrothermal modeling capability is
necessary because hygrothermal insulation instead of thermal insulation offers sig-
nificant economic advantages and could allow the development of walls to act as
heat and moisture exchangers.
It is time that building physics become re-focused on development of computer-
ized tools for predicting field performance of integrated environmental control sys-
tems. Better computer modeling is necessary to fine-tune the desired outcomes of
these systems and without these tools the performance of new systems cannot be
well understood and evaluated. Thus, building physics must create new tools to
reach an active and leading role in the movement toward net zero and near-net zero
energy buildings (NZEB).
For NZEB, multifunctional materials are a must
From a building science viewpoint, we have spent 5000 years in monolithic struc-
tures, the last 100 years in multilayered structures. Now, we are trying to reduce the
number of layers in the wall. To do it, we obviously need to use multifunctional
materials. While we talk multifunctional materials, we must also realize that criteria
for these functions are not defined on the material level but on the assembly level.
Building assembly is the lowest level in the building hierarchy in functional analysis
to which one can carry analysis down from the building level.
Observe that there is difference between science and many building codes where
requirements are ascribed to a specific material instead of an assembly. In some
cases, it works reasonably well while in others it is a miserable failure. For
instance, U values or thermal transmission in masonry buildings being ascribed to
the continuous insulation layer is close to an acceptable solution, but the same for a
steel frame building is not possible as it depends on where this insulation is located
and how environmental effects affect field performance. Even worse is the situation
about airtightness where permissible level of material airtightness is one magnitude
lower than that of an assembly and two magnitudes (100 times) lower than the
exterior wall of the building .
In reality, there is no conflict between building science and codes because codes
specify the minimum requirements and we should always design for requirements
higher than the minimum. Furthermore, codes deal only with the basic categories of
safety and health while the remaining categories are left for a qualified designer as
indicated in the above table.

8
For the sake of discussion, we consider four layers in any exterior wall, namely
(1) exterior facade, (2) exterior continuous insulation, (3) loadbearing (middle)
layer, and (4) interior trim and finish. It is clear that the facxade layer (1) must con-
trol fire, rain, air and water vapor entry, light, sound, radiation, and vermin; the
thermal insulation (2) controls heat, but may also control air, water, vapor, and
sound; the loadbearing layer (3) provides strength and rigidity but may also control
air, water, and vapor transports. Finally, the interior finish layer (4) should control
fire, air, water and vapor movements, and sound. Yet, the whole wall must be
durable, economical, and have control of ground water.
How are those layers actually working?
 Facxade layer may be either directly attached and perform required functions
or be a rain screen enclosing an air gap behind (e.g. brick veneer) to provide
rain control. In this case, the next layer, on the other side of the air gap,
should be a thermal insulating composite with a surface that fulfills all of the
facxade requirements.
 Thermal insulating composite must also control acoustics. This means that if
heavy concrete is not used for loadbearing, then the finishing surface on the
thermal insulation must contribute to the attenuation of structural vibration.
Today, however, popular solutions such as mineral fiber with wind protec-
tion or polystyrene boards with taped joints do not fulfill all requirements for
air, water vapor, and vermin entry.
 The selection of the loadbearing layer depends on the height of the building
but for a low rise a light-weight concrete with metal mesh reinforcement that
is additionally protected from corrosion is a suitable solution.
 The requirements for airtightness and fire resistance of interior finishes are
fulfilled by gypsum board that is water vapor permeable and have little
buffer capability
Effectively, one must remember that multifunctional materials are developed and
evaluated for a specific application and their use in different applications requires a
new evaluation.
An example of a multifunctional wall composite
Large windows exposed to the sun are recommended by many architects who fol-
low the wishes of the occupants. Glass connects occupants with the outer world
and is here to stay. So an engineer has to solve the technical problems instead of
trying to limit the size of windows. We have observed that windows expose occu-
pants to asymmetric heating and cooling surfaces and dynamic changes in air tem-
perature. To alleviate the discomfort issues, we need to re-examine two sets of
issues, namely:
(1) Dual function control for the water-to-water heat pump to address heating
and cooling required to control overheating.
(2) Re-circulation of ventilation air to equalize temperatures in sunny and
shaded areas.

Bomberg et al. 9
Figures 1 and 2 show that increasing thickness of thermal insulation to about
double of this that was introduced in 1970’s brought back the forgotten effects of
thermal bridges as their effect on temperature differences has also been doubled.
Figure 1. Infra-red camera sho ws all thermal anomal ies on exterior thermal insu lation
composite system with 14-cm-thick expanded polystyrene. Connectors and hot water lines are
shown as hot spots (HS) in contrast to corners and trees that are seen as cold spots (CS) .
Source: From Ad am Gryl ewicz (workshop at TU Cracow, 2015).
Figure 2. Facxade of a building at Cracow TU after thermal upgrade with ETICS having a thick layer of
thermal insulation. Drying on mechanical fasteners is faster that adjacent insulation that is still wet from
morning condensation. Source: Photo courtesy of Tomasz Kisilewicz.

Figure 3. Two fundamental requirements that are shown in a frame in the right, bottom corner impact the
process of integrated design of environmental control
The complex of factors interacting on IE is presented in Figure 3. It shows an
integrated heating, cooling, and ventilation system where a water-to-water heat
pump is supported by a solar thermal collector that heats and stores water. The
storage provides hot water through reinforced polyethylene (PEX) tubing to panels
located on the interior of the exterior wall. At the same time, a central air-supply
system, drawing geothermally pre-conditioned air, delivers it to each room. The
room (if it is exposed to solar radiation) is also provided with individual ventilation.
The framed area in Figure 3 (right, bottom corner) shows both the individual
ventilation and heating/cooling panel.
This solution addresses several different dimensions of IE, namely (1) IAQ, (2)
personal control of IAQ, (3) noise control, (4) individual ventilation, (5) thermal
comfort, (6) thermal, and (7) humidity buffers to reduce rapid changes in the IE.
These elements result in occupant satisfaction in the case of residences and
increased productivity in the case of work environments.
Figures 4 and 5 show the construction of a composite panel under discussion.
The structural support was made from 40-mm-thick extruded polystyrene board;
insulation board 1 was made from expanded polystyrene, while eco-wrap material
was lime–cement–ash mixed with rice fibers and hulls powder as well as other
industrial recycling materials. The heating/cooling pipe was 12mm in diameter.

Bomberg et al. 11
Figure 4. Multifunctional composite panel for interior of buildings (Hu, TU Nanjing, China
from the presentation at Workshop at TU Cracow, 2015
Figure 5. Multifunctional composite panel for interior rehabilitation of buildings (Hu, as above).
The reason for showing this example is twofold: (a) a demonstration of how
multifunctional materials and assembly form a seamless matrix of integrated design
and (b) to stress that during the integrated design one reviews all relevant experi-
ences in environmental control. Typical issues involve the following:
 Fresh air delivery. Note that the medical profession determined the amount
of fresh air needed for people about 100 years ago (Baker, 1912), yet
there is no consensus on how to overlay these requirements with different
HVAC systems whose air-mixing efficiencies vary. 1
 For a healthy ventilation system, all significant sources of pollutants should
be removed.

Bomberg et al. 12
 Large central ducts and short high-velocity small-diameter ducts show good
acoustical and air-delivery performance (Wallburger et al., 2010).
 Balanced ventilation systems that include supply and return ducts or central
supply with individual exhaust completing the supply have also a good
record of performance.
 Partitions (interior walls) in buildings to satisfy airtightness and of fire codes
create a multitude of zones with individual climate controls. Water-based
radiant systems with smart controls have a good record of performance in
maintaining thermal comfort.
 Water-to-water heat pumps used with hydronic heating systems can operate
at low temperature and be easily integrated with solar thermal panels.
 Variable refrigerant flow (VRF) technology allows using different heating or
cooling rates as required in different rooms.
 A dedicated central ventilation system is beneficial when dehumidification is
needed. With independent dehumidification and ventilation systems that
provide coupling to thermal mass, buildings can maintain comfort during
large periods of the summer simply by reducing humidity. This potentially
saves substantial amounts of energy.
Integration of testing and modeling on assembly level
In 1970s, when the theory of functional analysis was under international consider-
ation, a new category of performance tests was introduced. One example of such
test was an impact test that used a 50 kg mass sand bag on a 150cm string. Before
the test is started, the string is stretched horizontally. When released the gravity
forced the bag to go along a circle and hit the wall. This test obviously is better than
an impact test with a small and hard object but does it really represent a real hazard
of damage by impact?
We can call this a “performance-oriented” test because such a test is easier to
correlate with the damage mechanisms observed in the field performance. This may
be better understood when examining the stages in test development contained in
Table 2.
Looking at Table 2, one realizes that the vague objectives of performance-
oriented tests with unknown accuracy do not provide better linking the outcome of
the test to field conditions than it was a case with the standard rating test. Thus,
neither a rating test nor a performance-oriented test alone is sufficient for evaluating
field performance of a construction assembly. An assembly is a building element
such as a wall, door, window, or roof that consists of a combination of
materials and typically provides a separation between spaces. In many cases, one of
the spaces is the outdoors and if weather is a boundary condition describing it for
the purpose of modeling this requires a substantial set of skills.
Table 2. The process of test method development
 Identify factors leading to the objective
 Det ermine how to quantify these factors
 Choice of measuring method and unit test method)
 Write a test procedure

14
 Determine precision and bias
 Evaluating how the measurement meets an objective
Bomberg et al., (2016a), observed that almost all hygrothermal models used today
are simplified by neglecting capillary hysteresis despite the fact that such is
included in modeling used in soil science or in evaluation of stress/stain caused by
hygrothermal changes. Nevertheless, these models permit on evaluation of effects
such as material variability and changes in climate on the heat, air, and moisture
transmission through a building assembly.
Thus, like in other engineering disciplines, we must use a process of integrated
modeling and testing. This statement is self-evident because testing cannot address
the effects of variable weather conditions and modeling cannot address interaction
between structural and environmental stresses, strains, and probable deficiencies of
materials. Adamson et al. (1968) and later Bomberg and Allen (1996) have applied
the limit states
4
approach to energy efficiency and durability assessment. To
support modeling approach, Bomberg and Pazera (2010) extended the issues of
material characterization for input to hygro-thermal modeling and model
calibration.
5
We will continue this review in two blocks of issues:
 Energy efficiency of the building;
 Priorities in environmental control during design.
Energy efficiency of the building
Design of low-energy buildings by an integrated team brings a new demand for all
participants of multidisciplinary team. Understanding of how building functions is
necessary for solving conflicts arising between different requirements, for example,
continuity of function and separation of space.
To our knowledge, building physics is taught as individual subject and in most
cases with focus on specific technical solutions. This may be suitable for those who
major in the topic but for other engineers and architects the stress should be on
design principals and interaction of different subsystems.
To achieve this objective, we need to reform education process in civil, mechani-
cal, and architectural faculties by introduction of one subject that, for the sake of
identification, we call, “Principals of building science,” a course that should be
taught in parallel to low-energy building course.
Developing a vision for design of low-energy buildings
For many decades, we used reliance on air-conditioning to shape IE, neglecting
experience from time when buildings responded slowly to the change in exterior
4
Limit states methodology was introduced to structural dimensioning about 100 years
ago and in 1960s to building physics by a book in Swedish (Adamson, Bergstrom, and
Nevander) describing needs for Scandinavian research program.

climate and used interior thermal mass as a “heat battery.” To use controlled
thermal mass of the building interior and to restore the balance between
requirements for building enclosure and mechanical devices becomes a key to
sustainable design.
To this end, we propose a term Building with Environmental Quality
Management (EQM). The process of design and optimization includes three
stages:
 Using all possible passive measures in design of the house even though the
only two of the many existing passive house criteria are required. In this
process, new multifunctional materials and integrated HVAC with building
enclosures are introduced;
 Using low exergy geothermal and solar thermal measures to interact and to
extend passive measures;
 Using photovoltaics or other renewable measures to the extend economics
allows.
Developing a real-time hygrothermal models
We use the building component (assembly) level as the basis of evaluation. The
multitude of possible paths prevents us from going down to the material level. To
link materials with subsystems while simultaneously addressing the effect of mate-
rial variability and climate, we need to upgrade our modeling capability. One often
talks about modeling system to highlight the need for linking of these models.
Whether these models are linked with Energy plus or IDA-ICE, the hygrother-
mal part of the system must be:
(1) 2D or 3D real-time calculation code, that is, include capillary hysteresis
and continuity of momentum on the material boundaries;
(2) Have one set of output data allowing it to be considered as input to the next
calculation;
(3) Dynamically linked with whole building energy calculation;
Include verification of material and assembly characteristics.
Developing wall assembly characterization
Despite the fact that laboratory and field testing use the same scale and identical
construction, there is no equivalency between laboratory and field performance
test on assemblies. This is caused by the difference in the boundary conditions and
connectivity of the building assembly with adjacent assemblies. Air is entering to
the walls and floors in places much different than it is leaving the building. For
instance, air may enter through electrical or plumbing penetrations but exit at wall–
window interface. Results of the airtightness testing provide examples of missing
equivalency between laboratory testing and the difference is often as large as one
magnitude. Furthermore, field airtightness is often weather dependent.

15
To address the effect of weather, we must use hygrothermal models but these
models must be calibrated for the actual materials and wall assemblies.
Methodology of hygrothermal models verification and calibration on the material
level was discussed elsewhere (Bomberg and Pazera, 2010). Yet, there are no pub-
licly available methods of characterization of air flow through a wall assembly.
Such development is necessary if we want to use hygrothermal models for the real-
time calculations.
Experience indicates that such a method should be based on a combination of a
tracer gas and blower door technology to characterize degree of connectivity of a wall
assembly with interior and exterior air (Thorsell and Bomberg, 2011).
Closing remarks
A “White Paper’s” (research overview) role is to highlight week points in the emer-
ging knowledge and the process often starts with the vision. It may be stated that
over last 40 years we have produced enormous volume of new technology but with-
out the leading focus, this progress may not be efficiently used. We propose a new
label for our activity so that the vision of EQM would allow seamless connection
between HVAC and building enclosure as both of them shape IE. EQM includes
passive house design and low exergy measures; it does not change anything but
requires quantification of all effects of these measures that we undertake to manage
the indoor environment.
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, author-
ship, and/or publication of this article
Funding
The author(s) received no financial support for the research, authorship, and/or publication
of this article
.
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