3.1 Energy efficiency analysis through RTQ-R
In the case of external walls, for BZ2, the established value for thermal transmittance is U ≤ 2.5 W.m-2K-1 (INMETRO 2012), and for acoustic performance of external walls away from intense noise, according to the standard the soundproofing should be≥ 20 dB, for blind internal walls between living room or kitchen and eventual traffic areas, as corridors, soundproofing should be ≥ 30 dB (ABNT 2013a). Therefore, the LSF walls (Table 1) established in the project are in accordance with the requirements of Brazilian standards.In the evaluation of the topic of Minimum Wrap Performance, the analyzed project met the requirements of the PBE Edifica labeling with regard to thermal transmittance, thermal capacity, natural ventilation and natural lighting, according to Table 3.
Table 3 - Final analysis of the classification of the Housing Unit (HU) RTQ-R
Components analyzed
|
Score
|
Classification
|
Summer Wrap
|
4.35
|
B
|
Winter wrap
|
4.77
|
A
|
Water heating
|
3.00
|
C
|
Numerical equivalent of the wrap
|
4.58
|
A
|
Wrap ifartificiallycooled
|
5.00
|
A
|
Bonuses
|
1.03
|
-
|
Region/Location
|
-
|
South
|
Coefficient a
|
0.65
|
-
|
FinalHU Score
|
5.06
|
A
|
The project has the potential to obtain scores of 5.06 and classification A on the PBE Edifica seal, although the efficiency value for wrap in the summer was "B", due to the positioning of the first bedroom and office windows facing southwest, and the classification "C" for the water heating system. This was due to the fact that the solar water heating system was designed to supply between 60 and 69% of the hot water demand, including the use of the two showers at the same time, being complemented by electric heating.
3.2 Sustainable Sites (SS)
In SS all four prerequisites were met, the first requires erosion control, sedimentation and dust in the work, the second requires the use of adequate bioclimatic guidance for the implantation site, the third, the non-use of invasive plants. and the fourth requires that the land has infrastructure with water supply and sewage treatment, already existing in the condominium.
Regarding the prerequisite of Bioclimatic Architecture Guidelines, Brazilian bioclimatic zoning is defined through NBR 15220-3 (ABNT, 2005b), which establishes that for projects in BZ2 it is necessary to direct openings, from the environments of greater permanence of users, to the north, east, northeast, west or northwest, being these last two the last options. The project has reached this prerequisite, because the residence master bedroom and corridor are directed to the northwest, the windows of the living room are directed to the northeast and northwest, except for an area of light, which directs the opening to the southwest. However the incidence of sun in this window is limited by the garage wall, not being harmful in summer. The other bedrooms, office, kitchen and laundry, for limitations of the land, have their openings directed to the southeast.
Credit 1 (Certified Urban Development) cannot be applied, because the neighborhood where the project is inserted is not environmentally certified. Therefore, this score was not obtained, and it was necessary to analyze credits 2 to 5. With regard to credit 2 (Urbanization of the surroundings and walking streets) it was possible to get two points, because there are sidewalks in the condominium with width of 1.5m, the entrance of vehicles does not obstruct the sidewalk and there is a retreat of five meters in front of the lot to the sidewalk, which must not receive any walls or closures. The project includes walls of two meters on the sides of the land and a canvas in the background covered by native vegetation. As around the condominium the land was not previously developed, it could not obtain the credit 3 (Location preferably developed).
In credit 4 (Preservation or restoration of habitat) it was possible to obtain two points. Because the building construction coefficients were approved by the Municipality of Pelotas and the vegetation area of the land will be composed of at least 80% of native vegetation acquired from local floriculture. As the lot underwent grounding, the native vegetation would not be transplanted on site.On credit 5 (Proximity to community resources and public transportation), the busstop closest to the condominium is approximately 210 meters walk, and its daily routes are 179 total for both directions, totaling the achievement of 2 points in this credit.
On credit 6 (Access to open space) it was possible to obtain a point, because the condominium has 64.353 m² of green area, 28.416 m² of social space area with gym, walking track and bike path in the external area. The project land has a total area of 400.20 m², and as the total built area of the residence will be 181.43 m², there will be 54.67% of green area, with low, medium and high vegetation. However, as a plan for the preservation of trees and vegetation on the ground was not elaborated, the credit 7 (Reduction of the impact of the work on the ground) was not analyzed. Nor was analyze credit 8 (Landscaping), due to the landscape design not being finished.
For credit 9 (Heat Island Reduction) the areas listed in Table 2 and the Equation 1 were used. The calculation follows below, according to equation 2. It was possible to reach two points in this credit.
For credit 10 (Rainwater Control and Management), a point was reached, because the permeability coefficient of the land is 37%, adequate according to the legislation of the municipality and the condominium has rainwater retention for artificial lakes with retention time of at least 24h.
3.3 Water Efficiency (WE)
The project is in accordance with all the requirements of the prerequisites of this topic. For credit 1 (Efficient use of water - Optimized), three points were obtained, as there is the prediction of the installation of mixers for washbasin and showers with maximum flow of 6L.min-1 and the faucets of general use have restricted drive.
Because there is no sectorized measurement of water consumption, only at the water inlet of the local concessionaire, nor the forecast of the use of water that is not potable for the hydrosanitary system, and because there is no forecast for irrigation system for the garden, it was not possible to obtain scores on credits 2, 3 and 4.
3.4 Energy and Atmosphere (EA)
In EA, the project met all the prerequisites, as it met the requirements of the PBE Edificalabeling with regard to thermal transmittance, thermal capacity, natural ventilation and natural lighting. In addition to the specification that the residence will be delivered with the lamps and luminaires installed, and at least 80% of the points of light will have the Procel seal.
Credit 1 (Enhanced Energy Performance) cannot be analyzed because the project was not submitted to energy efficiency software simulation. For credit 2 (Obtaining the PBE Edifica label), it was possible to obtain two points, and for credit 3 (Enhanced Performance of the Wrap) two points, because the residence would reach level A of the PBE Edifica (Table 3).
For credit 4 (Efficient Sources of Solar Heating) it would be possible, with the choices for heating water between solar and electric, to obtain two points in this item. For credit 5 (Optimized Lighting), with the addition of installing lamps and luminaires with Procelseal throughout the residence and the use of presence sensors and photocells in external lamps, two points are achieved in this. With the use of at least 80% of appliances with Procel labelwithclassification “A”, it would be possible to obtain a point in credit 6 (Efficient Appliances).
It would be possible to obtain four points in credit 7 (Renewable Energy), considering that the photovoltaic energy production project includes the use of 20 photovoltaic panel boards in the residence, which will provide all the energy demand of the building. The surplus produced returns to the local electricity concessionaire and generates credits in the energy bill. However, credit 8 (Commissioning of Installed Systems) does not apply, because the residence did not start construction, and this research turns only to the potential application of LEED for Homes certification. As for credit 9 (Basic Energy Measurement), with the future sharing of photovoltaic energy production data with GBC Brazil, it would be possible to obtain a point.
3.5 Materials and Resources (MR)
Prerequisite 1 requires a Construction and Operation Waste Management Plan, which was made by the company responsible for the design and execution. The residuesgenerated are classified according to their characteristics of dangerousness established by the NBR 10,004 standard (ABNT, 2004) in Table 4.
Table 4 Solid waste generated and its classification of dangerousness
Classification (ABNT, 2004)
|
Waste
|
Class I D – Dangerous
|
Inkandsolventsludge.
|
Class II A
|
OSB boards, plaster, wood, paper and cardboard.
|
Class II B
|
Profiles in steel, cementitious plates, sheet metal, electro ducts, electrical wiring, pipes and connectors in PVC, EPS, concrete and gravel.
|
Prerequisite 2 (Legalized Wood) requires the use of legalized wood in the construction of the enterprise, which is acquired from registered timber, and that it can be reused in other works. The wood used in the sealing of the walls will be of the type OSB boards, of certified company, with the use of reforestation wood in manufacturing, with a 20-year warranty and anti-termite protection. As for the sidings of the work, these will not be wood, but recycled plastic material, environmentally certified and legalized.
On credit 1 (Construction Waste Management) it would be possible to obtain three points, the Waste Management Plan is in accordance with Brazilian standards (CONAMA 2002) and more than 80% of the waste generated will be recycled and/or reused.
The residence could obtain two points in credit 2 (Certified Wood), one point in credit 3 (Environmental Labeling Type I - Certified Woods) and three points in credit 5 (Environmental Labeling Type III - Environmental Product Declaration - EPD), because the OSB boards and the wood used will be acquired from a company that uses 100% reforested wood, with EPD, with green seal as established by ISO 14.024 and forest stewardship council (FSC) certified, that is timber from properly managed forests. In addition, more than five products that will be used and permanently used in the residence are certified, such as: plaster lining, plasterboard, mass for plasterboard joints, paper tapes and mass for cementitious board joints.
Credit 4 (Environmental Labeling Type II - Environmentally Preferable Materials) requires the use of materials that come from reuse, with recyclable content, rapid renewal and recyclable, aiming at reducing CO2 emissions and extracting non-renewable natural resources. According to Table 5, based on the total materials to be used, the company responsible for the design and execution states that 4.4% of the total cost of materials is with reuse materials, 62.72% with recyclable materials and 14.69% with materials of rapid renewal, meeting the percentages established by LEED certification. It is possible to obtain three points in this credit.
Table 5 Classification of materials used in the HU
Classification
|
% / total cost of materials
|
% requiredby LEED
|
Reuse materials
|
4.40
|
2.5
|
Recyclable materials
|
62.72
|
20.0
|
Fast-renewal materials
|
14.69
|
1.0
|
Total
|
81.81
|
-
|
In credit 6.1 (Dismountability and Waste Reduction – Structural Systems), it would be possible to obtain a point, because the LSF system is prefabricated, industrialized and can be assembled and disassembled in a practical, easy and fast way. Its waste generation is low, due to the modulation of the system and the use of industrialized materials. An LSF building can be dismantled if it needs, without losing its properties, and reassembled elsewhere, maintaining the same shape and structural strength. Because the fixing of the metal structure and the plates are made through screws, which makes the whole structure dismountable.
In the analysis for credit 6.2 (Demontability and Waste Reduction – Non-structural elements) it would be possible to obtain a point, because more than 60% of the non-structural materials are completely demountable, such as coatings of the internal and external walls, since they are elements screwed to the metal structure. The internal and external seals are composed of reusable and removable partitions. The PVC frames are fixed through screws, and the liners are in plaster, fully removable.
3.6 Indoor Environmental Quality (IEQ)
All the prerequisites of the item were reached, because in the project there is no prediction of the installation of equipment with combustion process within the internal spaces of the residence, and the openings met the requirements of Brazilian standards, including cross ventilation, ensuring a minimum air quality.Unfortunately, credits 1 (Thermal Performance) and 2 (Lumine Performance) were not met, because it was not possible to perform the software simulation of the energy and luminic efficiency of the building. However, in credit 3 (Acoustic performance) it would be possible to obtain two points, considering that the minimum acoustic performance was reached according to Brazilian specifications.
On credit 4 (Local humidity control) it could obtain a point, because the projects are equipped with waterproofing of boxes of bathrooms, with slope of the floor for sewage collectors and moisture resistant gypsum boards. Credit 5 (Protection of Pollutants From the Garage) requires carbon monoxide detectors if the garage is closed, however the garage gate will be leaked aluminum grid, allowing the constant exchange of air from the site, being possible to obtain a point in that credit.
To obtain three points in credit 6 (Contaminant Particle Control), the residence must have all ducts and openings sealed and opened after the end of all phases of construction. At the construction site there should be a demarcation for smokers, eight meters from the cafeteria, dressing room and work area.After the work is finished, contaminant control should be made in indoor environments with cleaning and cleaning of all rooms by a specialized company.
It would be possible to obtain two points for credit 7 (Low Emission Materials), with the use of materials of low urea emission, formaldehyde, levels of volatile organic compounds equal to zero. For credit 8 (Health and Well-Being) a point could be obtained because the requirements of the Implementation credit 6 were reached, about space for physical activities, and because the residence will be delivered with a User Manual, with an explanatory guide to the operation, maintenance and cleaning of the enterprise and its materials. The residence also has ventilation control with easily operable frames, keeping carbon dioxide levels below 800 ppm.
3.7 Social Requirements (SR)
The prerequisite would be achieved because the company responsible for the future execution of the work is with its regular legal obligations. Credit 1 (Universal Accessibility) requires that the enterprise be accessible to users with accessibility limitations. Because it is a single-site residence and a modular construction system that is easy to dismount, the necessary adaptations would be quick to accomplish, so the building would gain a point.
It would be possible to obtain a point in credit 1 (Good Practices for Design and Work) considering that all employees of the company are literate and have a course to implement the LSF system. The professional training courses for assembly of LSF are taught by the company itself and covers 100% of employees. This training is carried out during the execution of the work and the methodology includes the following stages: knowledge transmission, skills development, supervised experience and professional evaluation.
In credit 3 (Good Social Practices for Operation and Maintenance) a point can be obtained, because the owners receive, in an explanatory meeting, a User Manual, with all the information necessary for maintenance and use of the building. However, because the company responsible does not have a member of GBC Brazil, it is not possible to obtain a score in credit 4 (Leadership in Action).
3.8 Innovation in Design Process (IDP)
Prerequisite 1 (Operation Manual Use and Maintenance) was reached, because the owners of the building receive a User Manual, with all the projects and explanations necessary to understand the operation of the residence. Credit 1 (Integrated and Planned Project) grants three points with the existence of air conditioning projects, hydrosanitary installations, electrical and automation installations, integrated projects and planning for the execution of the work, prepared by professional architects or competent engineers.
In credit 2 (Education and Disclosure), to obtain two points, it is necessary to publish information, characteristics and benefits of the sustainable house and maintain the certification board of GBC Brasil Casa outside the residence, near the entrance. As for credit 3 (Innovation and Design) it is necessary to minimize the environmental impacts caused by the residence through the incorporation of sustainable techniques and constructive measures that bring benefits, in addition to those existing in LEED for homes certification.
Some benefits of LSF could be analyzed and compared to other construction systems, such as: use of water, cement and other materials, construction time, noise generated, the amount of material transport trips, influence of truck weight and fuel consumption, reduction of CO2 emissions during the construction period and use of the building, or the low impact on land movement and damage to buildings, justified by the use of surface foundation in the LSF system.
3.9 Regional Priorities (RP)
Credit 3 (Regional - South Priorities) for the southern part of the country requires obtaining the following credits, according to Table 6.
Table 6–Topics required by RP Credit 3 and achieved by the survey
Topics required by RP Credit 3
|
Achieved
|
SS Credit 5 - Proximity to community resources and public transport
|
Yes
|
SS Credit 9 -Heat Island reduction
|
Yes
|
SS Credit 10 - Rainwater control and management
|
Yes
|
WE Credit 2 - Sectorized measurement of water consumption
|
No
|
EA Credit 3 - Improved wrap performance
|
Yes
|
EA Credit 4 - Efficient sources of solar heating
|
Yes
|
EA Credit 7 - Renewable Energy
|
Yes
|
MR Credit 2 - Certified wood
|
Yes
|
As seven credits were reached, the residence could obtain a point, if it had reached the credit of Sectorized Measurement of water consumption, the building could receive two points.
3.10 Total score and suggestions for improvements
All the mandatory items of the eight topics evaluated were reached, and the score obtained from the non-mandatory parameters is shown in Table 7.
Table 7 - Application of the Check List LEED for Homes - GBC Brasil Casa
Topics
|
Total
|
Obtained
|
Percentage Achieved (%)
|
Sustainable Sites (SS)
|
21
|
11
|
52.38
|
Water Efficiency (WE)
|
12
|
3
|
25.0
|
Energy and Atmosphere (EA)
|
28
|
14
|
50.0
|
Materials and Resources (MR)
|
14
|
14
|
100.0
|
Indoor Environmental Quality (IEQ)
|
18
|
10
|
55.55
|
Social Requirements (SR)
|
5
|
3
|
60.0
|
Innovation in Design Process (IDP)
|
10
|
4
|
40.0
|
Regional Priorities (RP)
|
2
|
1
|
50.0
|
Total
|
110
|
60
|
54.55
|
The final residency score at LEED for Homes would be 60 points overall, which would classify it as GBC Gold Home. As the project did not go through energy efficiency simulation software, there was a loss of at least 16 points in the evaluation, which demonstrates its importance in the analysis of certification. The classification could be Platinum, if in addition to computer simulation, some modifications were made to the project, such as:
- Implementation in an environmentally certified neighborhood,
- Implementation close to communities with previous development,
- Have a plan to preserve the surrounding vegetation,
- Have landscaping project with regional vegetation,
- Have sectorized measurement of water consumption,
- Possess capture and use of rainwater for non-drinking consumption,
- Have efficient irrigation systems in the gardens,
- Have a water safety plan, which provides an action plan to minimize the health risks of residents,
- The benefits and innovations generated by the construction system in LSF were analyzed.
For the HU evaluated, because it has less than 300m² of built area, the investment required for its certification would be 4,000 reais (GBC Brasil 2017a, 2017b). This, if it were certified through GBC Brazil members, otherwise there would be a 20% increase in values.
The construction method in LSF showed several advantages, such as the use of certified materials, where maximum use was obtained in the topic Materials and Resources, in the energy efficiency provided by the composition of thermal and acoustic insulation used, in Social Requirements, while the system in LSF allows rapid reforms for adaptations of accessibility in the residence, and by the industrialized constructive method need operators trained with courses.