Design and Operation of Constructions: A Healthy Living Environment-Parametric Studies and New Solutions

Abstract

The problem of the environment in the inhabited area, in particular of the hygienic-sanitary comfort, are current topics of concern for the builders. The interest of the authors meets the requirements of the tenant. In general, it seems that the cause of the hygienic-sanitary discomfort of the inhabited environment would be the faulty execution of the construction or an inconsistent architectural conception; the current paper presents several factors that cause this discomfort, the tenant being just one of them. The result of faulty operation/utilization of living spaces is inadmissible for those who live there, both materially and with repercussions on their health. Additionally, this paper demonstrates the deficiency of the existing energy performance certificate. The results of our research offer real solutions in eliminating, solving, and correcting the hygienic-sanitary discomfort of the environment inside the buildings; this can be achieved by designing, executing and operating spaces correctly, adequately and optimally, ensuring a healthy environment. The authors propose to improve the norms of protection of the built environment, by modifying the related energy performance legislation/certificate; moreover, new and real practical solutions have been suggested by the authors for the prevention and remediation of hygienic-sanitary discomfort.

1. Introduction

Interior pollution of rooms with agents/substances that pollute the air in areas of buildings where people work daily or where they live, can often be more dangerous than outdoor pollution. This type of pollution occurs when volatile harmful substances act against a healthy living environment, resulting in the occurrence of respiratory diseases, more or less serious, or even cancer [1]. According to the World Health Organization, about 4 million people die annually due to indoor air pollution [2]. An important health issue is the indoor air pollution that demands sustained research and measures to ensure public health [1]. Statistics point out the connection between house dampness and respiratory disorders as mostly cough, respiratory infections, wheezing, upper respiratory tract disorders and asthma. These symptoms were present both in children and adults as revealed by researches carried out in different geographical areas [3,4,5,6]. Inside the residential buildings, the performance requirements specified in the norms and regulations in force must be complied with, implementing the European and national legislation, regarding the energy saving and thermal insulation, the hygiene-sanitary comfort, the health of the population and environmental protection, for a durable and sustainable approach [7,8,9]. Ensuring good indoor air quality as well as high energy performance of the building can be efficiently and effectively approached by neutralizing pollutants and reducing emissions of different sources [10,11].

Law no. 372/2005 regarding the energy performance of buildings, which entered into force in Romania on 1 January, 2007, continuously updated, establishes measures to increase the energy performance of buildings by saving energy and creating/ensuring hygienic-sanitary comfort. The Romanian legislation thus aligns with the European legislation in order to achieve the 20-20-20 EU energy targets [12].

The main objectives stipulated in the Directive 2010/31/EU of the European Communion that aim to decrease greenhouse effects refer to: diminishing greenhouse emissions in developed countries by 30% and increasing energy efficiency by 20% by the year 2020; using renewable energy up to at least 20% and raising the use of biofuels for transport by 10% by 2020 [12,13]. EU members adopted a resolution (October 2014) concerning the climate and energy issues by 2020, compliant with the long-term directions formulated in the 2050 Energy Roadmap: Roadmap for Moving to a Competitive Low Carbon Economy in 2050 [12,14].

The human population is also held responsible for the increase of GHG (greenhouse gases) and global warming, therefore people must take actions to reduce them. Approved European objectives concerning the climate and energy framework are mentioned in the literature data [13,14]. The European policy continuously stipulates directions of action concern clearly presented lying in the environment, human well-being and health [15]. The EU′s 7th Environment Action Program comprises three specific priority goals, one of them being to safeguard citizens from environment-related pressures and risks to health and well-being [16,17]. The effects of environmental pollution on human well-being and health are more evident in urban areas, because of various factors that have an impact on most of the population [18,19]. On the other hand, properly designed urban sites that have access to natural environments provide benefits for well-being and health [20]. The EU Green Infrastructure Strategy [21] and better area analysis may have a good impact on spatial planning and urban development.

In Romania, according to the data published on the website of the National Institute of Statistics, the total volume of construction works in 2017 and 2018 has decreased (explainable by the lack of large investments in infrastructure projects); in contrast, in the residential sector, the volume of construction works increased in 2017 by 70.5% compared to 2016, and in 2018 decreased by 23.5% compared to 2017 (according to partial statistical data). Overall, the residential sector is performing well, with successive increases two years consecutively (2016, 2017) compared to 2015; the year 2018, even though it shows decreases compared to the previous years, shows an increase compared to 2015 and 2016 [22].

Considering the important weight of residential and administrative constructions, the significant increase of their number, as well as the global trends for a healthier, ecological, sustainable, energy-saving environment, the topic addressed in this paper is actual and of great interest for architects, designers, builders, real estate developers and, last but not least, for ordinary citizens living or operating in these spaces.

Hygienic-sanitary comfort is vital for the health of the residents and for the integrity of the building. Studies concluded that, for people living and working in damp buildings, this increased the probability of having health problems like: respiratory disorders (affecting the nose, throat and lungs), asthma, hypersensitivity pneumonitis (an uncommon lung disorder triggered by the response of the immune system to multiple inhalation of substances that sensitize like fungi, chemicals, organic dust and bacteria), infection of the respiratory system, allergic rhinitis (hay fever), eczema, and bronchitis [23].

Ensuring hygienic-sanitary comfort in the construction of buildings involves several elements. This study refers to the significant architectural/construction elements of the buildings: the use of adequate materials; the correct design and execution of the roof and roof coverings and/or the roof terrace to drain water; structure and infrastructure; installations and equipment; meteorological water collection works; and land systematization works. An important place in this regard is occupied by the following items: the correct envelopment of the constructions with the elimination of the thermal bridges; the arrangement of efficient and easily manoeuvrable carpentry; and, a very important aspect often neglected, ensuring the possibility of building breathing, respectively evacuating the water vapours from inside the building to outside. A significant factor that helps establish the concentrations of pollutants in the indoor air is the rate of exchange of the air with the outside. The design, construction and operating criterions influence the air exchange rate, being a function of mechanical ventilation, infiltration and natural ventilation. At the same time, in considering a building that offers a comfortable and healthy environment, it will be equipped with efficient appliances for heating/cooling, ventilation if necessary, and to produce domestic hot water [24].

The idea of the present study came from the observations that, often, the occupants of the administrative buildings or the apartments in the collective residential buildings claimed the existence of a hygienic-sanitary discomfort of their environment, even in the newly constructed buildings; therefore, the authors wanted to clarify the causes of this discomfort. The purpose of this work is to support the provision of a healthy interior environment of buildings, through the intelligent and rational management of energy, as well as through the proper exploitation of buildings, installations and equipment [25]. Moreover, the authors would like to find and propose some new, real, practical solutions for the prevention and remediation of hygienic-sanitary discomfort. Additionally, possible modifications of the legislation in force (norms, energy performance certificates (EPC), which classifies the building/apartment in the energy class) have been studied, in an attempt to find optimal solutions that serve the same purpose of increasing the comfort of the tenant of a built space.

2. Materials and Methods

The study is based on the experience in the building’s design and conception and on observations of the construction expertise activity. Two specific situations were analysed for the subject approached: to provide healthy living conditions (agreeable from a hygienic-sanitary perspective) in inhabited new buildings (Case study 1) and in inhabited old buildings, of about 35 years old (Case study 2). For both case studies, specific investigations were conducted to determine the causes and eliminate the harmful effects on the inhabited environment.

The Case study 1 analysed the behaviour of an apartment in a new block, from the point of view of the thermal discomfort and of the hygienic-sanitary discomfort of the living space, respectively of the material repercussions of the two previously mentioned points of view. The apartment is located on the ground floor of a block of flats with height regime GF + 1F + A (ground floor, floor and attic); as for location on the ground floor, it is a corner apartment. The block of flats is located in the southern part of the Oradea city, Bihor county, Romania, with the orientation of the apartment being towards northeast. Through the initial project, the whole group was destined for a single-family dwelling GF + 1F + A. The project was elaborated in 2016 and the construction of the building was done in 2017.

The climatic characteristics of the area are represented by a climatic zone of summer temperatures: III zone with To = +28 °C (outside temperature); climatic zone of winter temperatures: II zone with To = −15 °C [26,27]. It is a continental climate zone with an average high temperature/year of 15.6 °C, average low temperature/year 5.5 °C, and average precipitation/year 603.2 mm [28].

Constructive description of the apartment can be presented as follows: the attic is in the habitable loft, insulated with 20 cm thick basaltic wool; the opaque perimeter closure is made of ceramic blocks with holes, having a thickness of 25 cm and a thermo-system made of expanded polystyrene of 10 cm thickness; near the socle, the polystyrene is 5 cm thick; the exterior part is made of PVC, with the usual insulating window; the entrance door of the apartment is metallic; and the heating system is a central heating type connected to the district heating system. The main features of the apartment are: height regime GF + 1F + A (ground floor, one floor and attic); usable area: 47.84 m²; free height level: 2.60 m. The access to the apartment is made from the entrance hall of the building, respectively from the staircase area.

The building is made punctually, from a single section, having the following composition: continuous foundations under structural walls, structural walls of masonry with hollow ceramic blocks, masonry of ceramic blocks confined with pillars, piles and belts of reinforced concrete, reinforced concrete floors, and a wood frame of carved resin wood with tiling of profiled tiles made of burnt clay. The finishes of the apartment are new and modern. The interior finishes are: levelled plastering on the walls, washable paints, tile in the bathroom and kitchen, warm floors of laminate flooring in the bed and living rooms, cold floors of tiles in the bathroom and kitchen, and PVC joinery with glazed windows. Exterior finishes are: noble plaster, facade thermo-system with 10 cm thick expanded polystyrene insulation, and socle hydro-insulated and thermal insulated with extruded polystyrene 5 cm thick.

The elements of installations are provided by the heating installation: the heating of the whole building is realized using static aluminium radiator elements; hot water consumption system: the building is connected to the hot/cold water networks of the city; lighting installation: the building is connected to the electrical networks through the connection wire.

Analysing the factual situation in the studied apartment, especially on the exterior wall (Figure 1a), visible degradation occurred, and it can be observed the mold/dampness presence. The outer wall of the E axis, facing North, in the socle area and above it, shows water infiltration, including dampness/mold. In the same situation is the corner of the E-3 axis (the E-axis wall being the outer, marginal wall, which delimits the studied apartment) area in Figure 1b.

The structural system is made of load-bearing masonry with pillars and reinforced concrete belts. In the area with accentuated mold problems (Figure 1), the pillar has increased dimensions (reinforced concrete pile), with thermal bridges being present (Figure 2a,b).

In order to have an eloquent image in the exploitation of the non-compliant elements listed above, measurements were made with the thermal imaging camera during the cold season (Figure 3a,b).

The thermally insulated concrete area, shown in Figure 2 and Figure 4, does not meet the hygienic-sanitary performance criteria, this area being an area with cold interior surfaces.

The groundwater level is high. In the geotechnical study elaborated in order to investigate the causes that led to the hygienic-sanitary discomfort, it is shown that “at the date of the execution of the geotechnical works on the site, the hydrostatic level was intercepted at a depth of −1.50 m from the land depth quota where it was also stabilized at the completion of geotechnical works on site. The specialized designer (resistance) takes into account that during periods of heavy rainfall, the water level in the meadow area of Crisul Repede (the river that crosses the city) can vary between 1.00–1.50 m” [29].

The geotechnical study provides for the construction of watertight sidewalks around buildings. “The sidewalk with a minimum width of 1.00 m will be placed on a layer of stabilized earth, in thickness of 20.00 cm, provided with a slope of 5% towards the outside. To be watertight, the pavement can be made of cast asphalt or stone or concrete slabs coated with cement mortar or bituminous mastic […]. The evacuation of surface water and the arrangement of the surrounding land surface will be done with slopes to the outside. The evacuation by pipe of the water must be done in impermeable channels, specially provided for this purpose, with secured outlets and, preferably, directly in the sewerage network” [29].

By measures of vertical systematization, it is necessary to avoid stagnation of surface water at distances <10.00 m, around each construction. The area defined by the project as a “fenced yard” is partially closed, similar to a balcony closed with polycarbonate plates, thus restricting air circulation and ventilating the apartment.

The expertise of the elements of non-compliant operation/use of the apartment concluded that the apartment, with a usable area of only 47.87 square meters, is inhabited by four people (a too large number), which, inside it, cook, wash and dry clothes (during the cold period of the year). The circulation of fresh air inside the apartment is limited on one hand, by the arrangement of polycarbonate panels and the “semi-enclosed courtyard” designed by the architectural project; on the other hand, by the improper ventilation of the living space (Figure 5).

The radiant elements (the radiant surface has been reduced to dispose of the radiant element in remaining limited space) and the furniture (extremely dense for the living space designed for 4 persons, in the studied apartment) are arranged so that warm air circulation is obstructed/restricted inside the house, during the cold period of the year. Subsequent finishes made by the beneficiary in the cold season (when the walls remained wet, not completely dried) do not allow ventilation/breathing of the building elements.

The investigation—Evaluating the factual situation of the neighbouring apartment shows that this apartment is symmetrically conceived, similarly designed and executed (only the interior finishes differ because they were in charge of the tenants, in this case); here, the circulation of fresh air is not limited, in the case of the fenced yard designed by the architectural project, there is only one cover, the enclosure being closed vertically with polycarbonate panels. The density of the furniture is not as high as in the studied apartment. The arrangement of the furniture, respectively of the radiators, does not limit the hot air circulation near them during the cold period of the year. The operation of the apartment is fair and rational, and there are no problems of hygienic-sanitary discomfort.

Investigations from the point of view of technical regulations, concluded paradoxically that the enveloping elements, considered separately, fulfil the condition R′ > R₀′nec (R′ the thermal resistance corrected, R₀nec the resistance, according to hygienic-sanitary considerations), of hygienic-sanitary comfort, as well as of energy saving condition; and R′ > R′min (minimum resistance, according to energy saving considerations), according to the regulations in force. From the point of view of the EPC, the construction is classified in energy class “A”.

The Case study 2 presents the behaviour of an apartment from a residential block of the 1980s; it is analysed from the point of view of thermal discomfort and hygienic-sanitary discomfort of the living space, respectively of the material repercussions of the two points of view mentioned above. The apartment is located at an intermediate level (7th floor), of a block of flats with height regime GF + 8F (ground floor and 8 floors), and as a location on the 7th floor being a corner apartment. The block of flats is located in the eastern part of Oradea, Bihor County, Romania, with the orientation of the apartment being towards North. Neighbourhoods are uninhabited apartments in which the heating is stopped (lateral and above), and the lower neighbourhoods are inhabited apartments. The climatic characteristics of the area are the same as mentioned in the previous case.

Constructive description of the apartment can be presented as follows: the building is made with the following structure of the coating: the roof of non-circulable terrace type, the perimeter closure is made of large prefabricated panels of 30 cm of resistance concrete of 12.5 cm inwards, thermal insulation of autoclaved cellular concrete (ACC) 17.5 cm; locally, in the kitchen, bathroom and the living room areas, the external walls are uneven (show deviations from the mentioned stratification), due to the trash chute and the structure of resistance (frames—Poles and beams); most of the windows are changed by the beneficiaries/owners, into windows with ordinary insulating glass; and the entrance door is new, simple, and made of PVC.

The main features of the apartment: the built area of the apartment is 84.24 m², the heated surface of the apartment is 71.07 m², the useful surface is 53.43 m², the heated volume is 181.23 m³, and the free height level is 2.55 m. The access in the apartment is the same as in the Case study 1. The apartment was recently rehabilitated and refurbished, through interior modifications: the walls between the kitchen, pantry and entrance were removed and the wall of the service toilet was modified; the parapet below the window between the room and balcony, kitchen and balcony were removed, hp = 0 (the height of the parapet); as well as mounting of a door-window. The balcony from the room in the side facade was closed with PVC joinery and glazed windows. The access in the apartment is made through the entrance, where from the two parts of the house are accessed: the living part with the living room and kitchen (mono-volume), respectively the resting part, with the two bedrooms and the bathroom.

Elements of structural composition: the building, in regime GF + 8F, is made punctually, from a single section. The resistance structure of the block consists of: diaphragm walls and frames (beams and poles) of reinforced concrete, slabs of prefabricated reinforced concrete, isolated foundations under pillars and continuous under the basement walls.

The finishes of the apartment are new and modern. The interior finishes are: levelled plastering on the walls, false plasterboard ceiling in some places, washable paints, tiles in bathrooms and kitchen, warm laminate flooring in the room, cold floor tiles in bathrooms and kitchen, and PVC joinery with glazed windows. Exterior finishes are: initial plastering of the block and unenveloped exterior opaque surfaces.

The heating system is part of the elements of installations; the heating of the whole building is central heating. The radiators are made of steel sheets, equipped with double corner adjusting valves, return corner holders and manual ventilation valves, provided with heat dividers. Measuring the thermal energy consumed for heating was established both at the building level and through dividers, at the apartment level. Hot water for consumption installation: the building is connected to the hot/cold water networks of the city. The lighting installation is ensured by connecting the building to the electrical networks, through the connection wire.

Analysing the factual situation in the studied apartment, the presence of mold/dampness is observed on the delimitation elements adjacent to the unheated neighbourhoods (ceiling/walls), but also on the exterior walls of the dwelling (Figure 6a–d).

To the enveloping of the apartment, respectively the closing elements, are added the partition walls to the unheated neighbour apartment, respectively the slab that separates the heated apartment from that of the neighbour above (the unheated house). The characteristic elements of the enveloping are described in

Table 1. The thermo-technical characteristics of the exterior walls—the envelope, the surfaces to unheated neighbourhoods, and the PVC joinery—the envelope (without shutters).

The Thermo-Technical Characteristics of the Exterior Walls—the Envelope
Orientation	Surface [m2]	Component Layers (i→e)			Reduction Coefficient r	Corrected Resistance R′ [m2K/W]
		Material		Thickness [m]
N-V	22.15	Mortar		0.020	0.65	0.61
N-E	12.68	ACC Masonry		0.125
S-V	4.29	Reinforced concrete		0.175
		Mortar		0.020
Thermo-technical characteristics of the surfaces to unheated neighbourhoods
Description	Surface [m2]	Component Layers (i→e)			Reduction Coefficient r	Corrected Resistance R′ [m2K/W]
		Material		Thickness [m]
Floor	71.07	Decking		0.05	0.8	0.24
		Plate concrete		0.12
		Plaster		0.02
Wall	13.21	Reinforced concrete		0.14		0.23
Thermo-technical characteristics of the PVC joinery—Envelope (without shutters)
Description		Orientation	Surface [m2]	Sealing Degree	Corrected Resistance R′ [m2K/W]
Insulated windows/doors interior opening		N-V	7.77	With sealing measures	0.500

.

The total surfaces of the enveloping elements and their corresponding average thermal resistance are shown in

Table 2. Envelope of the studied apartment vs. virtual apartment.

Construction Element/Type		Total (m2)	R′med [m2K/W]
Studied Apartment
Exterior carpentry	PVC	13.05	0.306
Exterior walls	Exterior wall	39.12
Unheated neighbourhoods	Unheated wall	84.28
Total		136.45
Virtual apartment
Exterior carpentry	PVC	13.05	1.505
Exterior walls	Exterior wall	39.12
Unheated neighbourhoods	-	-
Total		52.17

.

The average corrected thermal resistance of the real apartment results in R′med = 0.306 (m²K)/W [30]. In order to have an eloquent image, in operation of the non-conforming elements of the enveloping, measurements were made with the thermal imaging camera in the cold season (comparative thermo-vision images in Figure 7a–c).

For delimitation surfaces of the unheated spaces of the studied apartment, in

Table 3. Comparative norms—thermo-technical characteristic surfaces to unheated neighbourhoods.

Description of Surfaces to the Neighbour	Surface [m2]	Corrected Resistance R′	R′min	R0′nec
		[m2K/W]
Floor	71.07	0.24	2.00	0.31
Wall	13.21	0.23	1.40	0.24

are shown: the values of the corrected thermal resistance, R′; the normative values of the minimum resistors from the energy saving condition, R′min; and the normative values required from the hygienic-sanitary condition, R₀′nec. For the calculation of R₀′nec, an average temperature of 10 °C was considered in the unheated neighbourhoods. A virtual apartment, similar to the real one, but with normal functioning (with the heated neighbourhoods) was studied for comparison.

If the neighbourhoods are heated, the enveloping elements of the apartment, considered in the calculation of energy consumption, would be only the exterior elements of the apartment, that of carpentry and exterior walls, shown in Table 2. The average corrected thermal resistance of the apartment with normal functioning, with heated neighbourhoods is Rm′ = 1.505 (m²K)/W, according to the relation (9.5.1.) of the Methodology, part I [30]. The energy performance certificates of the real apartment, with unheated neighbourhoods, and of the virtual apartment, with heated neighbourhoods are shown in Figure 8a,b.

Parametric studies for the Case study 2 are as follows:

• Comparative study—The energy saving criterion (Table 3). In order to save energy in operation, the comparison is made between the values of the thermal resistance corrected on elements calculated for the real building and the normative values of the minimum thermal resistance corrected (the reference building).
• Comparative study—The hygienic-sanitary and comfort criterion of the real living apartment (Table 3). In order to ensure hygienic-sanitary conditions and comfort in operation, there is a comparison between the values of the thermal resistance corrected on elements calculated at the real building and the normed values: the minimum thermal resistance required for hygienic-sanitary considerations on the whole building, for exterior walls.
• Comparative study—The energy requirement and the energy performance class of the real apartment and the virtual apartment are presented in

  Table 4. The parameters of the real apartment vs. virtual apartment.

  Parameter	Unit of Measure	Apartment		Difference
  		Real	Virtual	%
  Average resistance Rm′	[m2K/W]	0.306	1.505	−79.67
  Total annual specific energy requirement	[kWh/m2 year]	350.69	252.78	+38.7
  Specific annual energy requirement for heating		209.52	111.61	+87.0
  Energy performance class	-	D	C	-
  CO2 equivalent emissions	[kg CO2/m2 year]	168.33	121.33	+38.7

  . The energy performance class allows, by analysing the parameters contained in the EPCs, the comparative study of CO₂ equivalent emissions in the cases of the real and virtual apartments.

The presence of mold/dampness on the delimitation elements adjacent to the unheated neighbourhoods (ceiling/walls), but also on the exterior walls of the dwelling, is due to the irrational use of the inhabited space by all the inhabitants of the building (especially the immediate vicinity of the studied apartment, not heated in the cold season).

Table 3 shows that the criterion of satisfying the thermo-energetic performances due to energy saving considerations, is met: R′ < Rmin′ (m²K/W), on the whole of the building, for exterior walls and for the slab to unheated neighbour apartments; also being observed that the criterion of satisfying the thermo-energetic performances for hygienic-sanitary and comfort reasons, is not met: R′ < R′ (mpK/W), on the whole of the building, for exterior walls and slab/ceiling [31,32,33]. Table 4 illustrates that: for heating, the necessary energy required to reach the same parameters is 87% higher in the case of the real apartment than for the virtual one, with the heated neighbourhoods; the total specific energy required to reach the same parameters is 38.73% higher for the real apartment; CO₂ emissions for reaching the same parameters are 38.73% higher for the real apartment; and the average thermal resistance of the real apartment is with 79.67% lower compared to the average resistance of the virtual apartment.

3. Results

3.1. The Relevant Results of Case Study 1

Corroborating all the data and information mentioned in the description of the Case study 1, it is considered that due to the overlap of the adverse effects of several factors, the operating behaviour of the apartment, from a hygienic-sanitary point of view, is not appropriate. These factors that determine the hygienic-sanitary discomfort of the apartment are: architectural design, execution, and exploitation.

From the architectural project resulted the presence of thermal bridges along the respective socle in the corner of the intersection of the E-3 axes, while the details of execution were not conclusive. After analysing the execution, it was resulted: the lack of the waterproofing layer between the foundations of the building and the ground floor masonry, respectively the water permeability of the concrete from the foundations with the possibility of ascending the water to the walls, including the walls of the E axis and the E-3 corner (the groundwater level is high, according to the geotechnical study). It also resulted in the non-evacuation of surface water according to the recommendations of the geotechnical study (by not executing the proper sidewalk along the E-axis wall, respectively, not evacuating the surface water from the site). At the same time, it should be remembered that the finishing was done in the cold season, so the walls stored moisture, which they failed to remove (this remained largely in the structure).

During the operation, there was a change of the original construction destination from GF + F + A residential house to GF + F + A block of flats with apartments increasing the number of people occupying the living environment. The non-compliant exploitation of the apartment by the tenants, was observed according to the aspects listed in the description of Case study 1.

Material and comfort aspects found after the investigations are represented by the decreased hygienic-sanitary comfort, decreased value of use of the apartment, and decreased market value of the apartment.

The punctual solutions to remedy the existing situation, for Case study 1, are listed below:

• Conception—Design: (1) partial/total disposal of the polycarbonate panels (walls) in the fenced yard area designed by the architectural project to facilitate air circulation when ventilation of apartment is intended; (2) adjusting the heating installation/respecting the heating project, with the verification under pressure of the installation; (3) preventing the rise of the groundwater to the surface, in the walls of ceramic blocks (by applying an additional waterproofing layer, between the elevation and the masonry or by local vitrification in the affected area); (4) the proper waterproofing of the socle, on the splashing area on the sidewalk; and (5) possibly, completing the corner over the entire height with polystyrene profile of 3–5 cm, in order to correct the thermal bridge.
• Execution: (1) carrying out the works in the hot season, to evaporate the water stored in/to dry the walls; (2) uncovering at least the base of the building in the area of axis E and corner 3-E in the warm season and allowing to dry/evaporate the water, with the restoration of the thermo-system after the warm period; (3) the rehabilitation of the sidewalk along the E axis, in compliance with the recommendations of the geotechnical study, respectively the removal of superficial water from the building area, the sidewalk should have an outward slope of at least 3%; and (4) ventilation of the layer/film between the support and polystyrene, under the slab over the ground floor by making perforations through the thermo-system, up to the support/masonry covering of the perforations with the perforated covers set on the entire (lateral) facade at 50–75 cm.
• Exploitation: (1) rational use of the living space through proper and efficient ventilation of the apartment, at a minimum rate of 0.5 m³/h; (2) the correct exploitation of the living space (ventilation, adequate furniture, not drying the laundry in the apartment, arranging and using the hood in the kitchen, not keeping pets inside, allowing sunlight to enter), taking into account the large number of people occupying a small space; (3) monitoring the humidity level by arranging a hygrometer to monitor the humidity, identifying and eliminating the sources of humidity; (4) installing dehumidifiers; and (5) achieving and maintaining constant interior temperature (20–21 °C) during the cold season.

3.2. The Relevant Results of Case Study 2

Corroborating the numerical results that characterize the thermal resistances of the enveloping elements of the real apartment with the data from the site (measured temperature of the living environment), the factors that determine the hygienic-sanitary discomfort of the apartment are observed: the decrease of the thermal comfort because the interior temperatures in the studied apartment are lower than the designed parameters, due to the unheated neighbourhoods; the existence of temperature differences between the living environment and the interior surface of the wall that delimits unheated neighbourhoods, their temperature being significantly lower than the interior temperature of the inhabited apartment; and the existence of great temperature differences between the heated and non-heated spaces, due to the fact that the apartments adjacent to the one studied are not heated during the cold period of the year. These facts lead to vapor condensation on the cold surfaces of the neighbourhood walls.

Material and comfort aspects found after the investigations can be pointed out as follows:

(1)

According to the energy performance certificates [31,32,33,34] presented in Figure 8, the studied apartment is in the energy class D, having the energy rating 79. Under normal operating conditions, with heated neighbourhoods, the apartment would be in energy class C, with energy rating 87, because, in order to obtain the same thermal comfort, a significantly lower amount of energy would be consumed for heating the apartment, which would mean reduced costs with heating.

(2)

The system of heat dividers and thermostatic valves is not efficient in this case, noting that the costs of those who do not heat the apartments decrease on account of those who extra heat, due to the lack of heated neighbourhoods.

(3)

The use value of the apartment is diminished.

(4)

The market value of the apartment is diminished.

The punctual solutions to remedy the existing situation in Case study 2 are defined below:

• Conception—Design: (1) adjusting by the owner of the heating installation; and (2) rehabilitation of the studied apartment with its enveloping towards the unheated neighbourhoods (and to the outside), which means additional expenses for it, that exceeds the purpose for which the building was designed.
• Exploitation: (1) the compulsoriness to heat all the apartments of the building; and (2) rational use of the living space.
  Additionally, the solutions to prevent hygienic-sanitary discomfort in living spaces are linked to the next aspects:
• Conception—Design—Execution: (1) the beneficiary should request a complete project with execution details; (2) consistent design with studying the orientation of the functions of a living space towards the cardinal points, taking measures to remove the water from/near the building, preventing the hygienic-sanitary discomfort through conception and design, respectively avoiding the material repercussions imposed by healing/solving it; (3) correct execution; and (4) performing plastering and finishing works in the hot season, for the evaporation of the water stored in or drying the walls.
• Operation: (1) occupying the built spaces by an adequate number of persons; (2) in the case of apartment blocks, there should be the obligation to heat all the apartments of the building; (3) smart ventilation of occupied spaces; proper ventilation (with heat recovery in the cold season); (4) monitoring the humidity level; (5) installing dehumidifiers, if necessary; (6) achieving and maintaining constant indoor temperature in the cold season; and (7) periodic auditing/expertise of the constructions. During the operation of the studied apartment, different situations of operating the neighbouring apartments may occur such as giving up their heating, which requires another way of maintaining/operating the apartment in question. This fact further justifies what the present paper proposes: By means of legislative interventions it is required to periodically audit the living conditions—our research proposes an interval of no more than 10 years, equal to that of the validity of the EPCs.

The EPC of the construction does not give information on the humidity status of the interior walls and ceilings of the buildings, areas that can influence the hygienic-sanitary comfort inside the buildings. Figure 9 shows the proposal of the authors to modify the EPC.

The energy rating of the building takes into account the penalties due to the irrational use of energy. This study proposes that in the elaboration of the EPC, in the section “Penalties granted to the certified building and their motivation” [33] (second page of the EPC), similar to the diminution of the score granted to the building on the outer walls by the coefficient p₉ (coefficient of penalty according to the state of the outer walls, from the point of view of their moisture content, determined for the current form of the EPC according to

Table 5. p₉ coefficient of penalty according to the state of the outer walls.

Situation	Coefficient
Exterior walls	p9
Dry exterior walls	1.00
The outside walls have stains of condensation (in the cold season)	1.02
The exterior walls show traces of dampness	1.05

), to introduce the following penalties:

• p₁₀—Penalty coefficient depending on the state of the interior walls in terms of their moisture content;
• p₁₁—Penalty coefficient according to the state of the ceilings in terms of their moisture content;
• p₁₂—Penalty coefficient depending on the condition of the floors in terms of their moisture content; determined according to

  Table 6. New parameters suggested to be introduced in Energy Performance Certificate (EPC): p₁₀, p₁₁, p_12.

  Situation	Coefficient
  Interior walls	p10
  Dry interior walls	1.00
  The interior walls have stains of condensation (in the cold season)	1.02
  The interior walls show traces of dampness	1.05
  Ceiling	p11
  Dry ceiling	1.00
  Ceilings have stains of condensation (in the cold season)	1.02
  The ceilings show traces of dampness	1.05
  Floors	p12
  Dry floors	1.00
  Floors have stains of condensation (in the cold season)	1.02
  The floors show traces of dampness	1.05

  . The numbering of the other coefficients will be shifted, thus reaching a number of 15 coefficients of penalty for the certified building.

4. Discussion

The results of this study indicated the presence of hygienic-sanitary problems in the two studied houses, problems determined by a number of overlapping factors. The problem of hygienic-sanitary discomfort of the inhabited areas, of the occurrence of the dampness/mold during the exploitation of the constructions is mainly due to the excessive, uncontrolled humidity, the causes being often hidden. The high humidity in building materials (which causes condensation on surfaces) must be differentiated from the humidity in the air in the living spaces. Several studies have associated slightly increased air humidity in houses or offices with beneficial effects on health and work capacity [35,36].

The National Institute for Occupational Safety and Health (NIOSH) Respiratory Health Division director, David Weissman, stated that the implementation of periodic controls for dampness helps to discover the affected areas and take actions (make repairs) in time [37]. For cases of hygienic-sanitary discomfort, Washington—NIOSH suggests a four-step evaluation and monitoring (checklists to help employers assess damp areas and identify mold): (1) Evaluation—find dampness and mold in all sectors of the building(s) using specific tools; (2) Identification: discover the source(s) of mold or dampness found in step 1, paying attention to what generates the moisture; (3) Remediation and Reparation: trained specialists are to repair the sources of damage and remediate affected areas according to adequate guidelines; and (4) Repetition: establish periodic assessments of the building to avoid the occurrence or aggravation of existing damage and resumption of step 1.

Decreased hygienic-sanitary comfort in a part or apartment of a building leads to the degradation of the entire building over time. The consequences are equally influencing the health of those living in these locations, as well as the performances (energy, thermal, etc.) of the construction.

These data have led to the identification of specific solutions, both to remediate the existing situations and to prevent the hygienic-sanitary discomfort in the inhabited spaces. In order to ensure a healthy living environment and even the safety of buildings, some changes are required such as: improving the legislation related to the protection of the built interior environments and modifying the CPE of the construction, so that it also gives information on the hygienic-sanitary comfort offered by the building.

It is recommended for the occupants of the apartments or spaces within a collective building, within a period of 10 years (validity period of the energy certificates) to expertise/audit from the point of view of hygienic-sanitary comfort of the living environment, the apartment or the building, as is the case. For the cases in which hygienic-sanitary discomfort phenomena occur, the legislation regarding the protection of the inhabited environment, should impose on the owners/occupants of the buildings the obligation to eliminate the causes of their occurrence and/or the punctual or global rehabilitation of the construction. This is necessary to ensure a healthy living or working environment for the occupants of the space and to prevent the degradation of the building.

Inspired by the model from “General Buildings Form & Instructions” of the NIOSH, Centres for Disease Control and Prevention of the US [22], in the energy audit/hygro-thermal expertise, the authors of this paper propose to quantify the size of the moisture/mold/dampness stains existing on the horizontal and vertical construction elements such as walls and floors, as well as the identification of the degraded or just stained surfaces, the surfaces with visible mold and of wet surfaces as described in Table 6. Depending on these quantifications, the intervention solutions for repairing/rehabilitation, respectively for removing the causes of these degradations will be recommended by the expert [23].

5. Conclusions

Results of our work show that the hygienic-sanitary discomfort must be prevented by: conception—initial coherent design of the building; correct execution; rational exploitation of the inhabited environments at the apartment level (in the case of a block of flats); and at the level of the whole complex, of the entire construction. Based on these case studies, this paper emphasized that, in the case of developing the EPC of the building, it does not take into account the hygienic-sanitary comfort of the populated/inhabited environment. In this regard, the present research proposes that the EPC provide information on the condition of the interior walls, of the ceilings, and of the floors, in the same way that, at present, the EPC gives information on the condition of the exterior walls. More studies that analyse different types of buildings with different destinations and in different areas of the country are needed to identify the best practical solutions for obtaining/maintaining sanitary comfort in living spaces or with other destinations.