Apartment with Acoustics Environment Approach in Center Jakarta

Environmental acoustics have an important architectural role that has a major influence on the productivity, health and sustainability of cities. living and proximity to the workplace have become essential needs for workers and entrepreneurs in today’s era. As many still work using the hybrid system, where workers require a comfortable living space as well as a comfortable workspace to support productivity, meetings and work can be done in the same place. SOHO apartments provide a solution to this problem, but they are prone to acoustic issues due to their open plan and loft concepts. The large volume of space requires special treatment, especially in terms of reverberation time. Excessive reverberation time can disrupt the productivity of residents and workers. A quiet space is needed to support these activities. This study aims to explain how environmental acoustics can improve the quality of a room and increase productivity and healthy through the application of acoustic absorbent material. However, the use of absorbent material is not very good for the environment if its use is not appropriate, therefore the selection of absorbent material must be analyzed carefully, so that what is obtained is PET (Polyethylene Terephthalate) material which supports all aspects of the SOHO apartment’s space needs and also material recycling up to 90%-99% which is good for sustainability. This study uses a combination method of observation and precedent studies. The results of this research involve the application of parameters to address acoustic issues in SOHO apartments and improve the acoustic quality of the space.


Introduction
Environmental acoustics, or architectural sound control, is a branch of environmental control in architectural space.One can be an architect creating an environment, where conditions improve ideally provided, whether in closed or open spaces and the occupants of the spaces architectural inside and out noise control at this time can create complex built environments in buildings that have fulfilled all the physical, physiological and psychological requirements of the occupants, in this case the artificial environment created is superior to natural conditions Creating space to control sound creates an environment acoustics that are second to none in nature.In this case it is clear that an architect has the ability to achieve this, which is sometimes very complicated.[1].
Jakarta is the capital of the Republic of Indonesia which is a business center and also has the most densely populated population in Indonesia.Not only that, Jakarta has a population of around 10,609,681 1324 (2024) 012035 IOP Publishing doi:10.1088/1755-1315/1324/1/012035 2 people [2].Population of Jakarta continues to increase every year.However, the availability of housing units still cannot meet the needs, creating a gap between the supply and demand for housing in Jakarta.
In 1972, only 30% of land in Jakarta was used, but it increased to 90% in 2002 [3].Based on this data, it indicates that the growth of horizontal housing will decrease, and it will change to vertical housing (Urban Sprawl Theory).Based on the above data, the appropriate project choice is an apartment, which is a vertical housing unit.However, besides the limited remaining land in Jakarta, Therefore, living near the office is essential for people today, especially in Jakarta, as commuting time to the office is better spent with friends, family, and pursuing hobbies.However, another problem is that the cost of buying a house is too expensive, so most people choose to rent a place to live near the office [4].Based on this data, the selection of a site needs to be close to the office area so that apartment residents can work and socialize not too far from the workplace and easily accessible.Traffic is not the only problem, but how people walk inside the building where they live is also a significant factor causing acoustic problems and disruptions [5].
Due to the site being located in Central Jakarta and targeted users are workers or entrepreneurs, it is necessary to collect data on whether there are SOHO concept apartments around the site because SOHO apartments are the most preferred choice for workers or entrepreneurs and have criteria that workers or entrepreneurs want, such as a strategic location, time and mobility efficiency, work-time flexibility, and efficiency of quality time [6].Within a 1.5 km radius, there is Citylofts Sudirman, which is a SOHO concept apartment.Based on mapping from this location, it can be concluded that there is still a lack of SOHO concept apartments in the site area that can strengthen the development of SOHO concept apartments in that location.
Acoustic problems not only occur outside the building but also inside the room, called Reverberation Time (RT), and Noise Reduction (NR) can help reduce the noise.It is known that both acoustic problems that occur outside and inside the room are detrimental to users, in this case, it can disrupt the productivity of workers who are still using the hybrid system.Therefore, the stability of sound quality in the room, natural sound quality, and acoustic consistency in the room must be considered [7].
With the data that there is still a widespread desire to undergo a hybrid work system, the occupants of the workers want a space that has high flexibility because it is believed that this flexibility can help workers to be more productive when carrying out the hybrid system.The pandemic changed the habit of working from home or hybrid, now workers need more work space and private places (Privacy).The SOHO concept of housing emerged when many professionals began to consider efficiency, flexibility and privacy when working, especially those engaged in small-scale businesses or workers [8].
According to Imelda Akmal in her book: "SOHO or Small Office Home Office", in 2013, everyone who wants to work from home has different motivations or goals.Some want to be more flexible about time and work, some want to have more opportunities with their family, or want to get comfortable working from their own home.In essence, the SOHO concept aims to facilitate the completion of work in a professional manner without neglecting attention to the family.In terms of room design, SOHO generally has a Loft-shaped design with high ceilings to design mezzanine floors and also open plans [5].With this design, the SOHO concept (High Volume, Open Plan and high ceilling) apartment with this loft type tends to have acoustic problems, namely Reverberation Time (RT) [9].
This problem can interfere with all activities carried out by workers, starting from speech actions, online meetings, and other productivity activities.Based on these problems, this research is more concerned with interior acoustic problems.Acoustic material can be one of the solutions for optimizing excessive Reverberation Time and also as Noise Reduction, acoustic material is one of the most important aspects in determining the optimization of a room's reverberation time (Samodra, 2018).those requiring clear information delivery have a recommended reverberation time of 0.7 -1.1 s [10].
This research is in accordance with point 11 of the Sustainable Development Goals (SDG), creating urban green open ratio housing, which is expected to create cities and human settlements that are inclusive, safe, resilient and sustainable.This study aims to explain how environmental acoustics can improve the quality of a room and increase productivity and healthy through the application of acoustic absorbent material.However, the use of absorbent material is not very good for the environment if its use is not appropriate, therefore the selection of absorbent material must be analyzed carefully, so that what is obtained is PET (Polyethylene Terephthalate) material which supports all aspects of the SOHO apartment's space needs and also material recycling up to 90%-99% which is good for sustainability.

The method of study
This research will be conducted using a mixed method approach that combines both quantitative and qualitative methods.The qualitative method will be carried out through observation, precedent study, and literature review.According to Moch.Nazir (2011), qualitative or descriptive method is a method of researching a set of conditions or a class of events in the present.the aim of this method is to create a systematic, factual, and accurate description, picture, of painting of the facts, properties a relationships among the phenomena investigated.Meanwhile, the use of comparative method will be done by making a comparison study between SOHO apartments with the use of acoustic materials and SOHO apartments without the use of acoustic materials.In the quantitative method, a research approach that uses numbers will be used, starting from data collection, interpretation of the obtained data, and dissemination of the results using the theory of Reverberation Time (RT) and Noise Reduction (NR).
This research uses primary data in the form of online and offline observations of apartment units to determine the use of acoustic materials in those units.This secondary data collection was taken from literature studies to obtain data on the correlation coefficient and efficiency of the use of acoustic materials in a room.The author used Leslie Doelle's textbook titled "Akustik Lingkungan" and Prasetio Satwiko's book titled "Fisika Bangunan" as literature guides for this research.

The case study
In this study the authors took data from Apartment SOHO Daan Mogot Jakarta and Citylofts Sudirman Apartment, for analysis Reverberation time and Noise Reduction.Based from Table 1 it was discovered that the reverberation time in the SOHO type C room is relatively high at 4.74 seconds, the standard for workspace and clear speech information is 0.7-1.1 seconds [9].In addition, it is known from the simulation using Autodesk Ecotect Analysis 2010 software that there are acoustic reflections in the apartment unit.From Figure 2 simulation results show that the sound mainly distributes on the first floor and there are few reflections on the second floor.Based on the simulation results, it can be concluded that the use of acoustic materials can be focused on the first floor, and the use of acoustic materials on the second floor can be minimized.

Analysis Absorber Material
Material Absorbers have various types with functions to absorb sound, such as Polyethylene Terephthalate (PET), Fabric, Polyester Fiber, Wood (MDF), and others.According to Sutanto (2015), the selection of acoustic materials requires consideration of factors such as sound absorption coefficient, aesthetic appearance and character suitable for the room, material resistance to fire, fungi and durability, ease of maintenance, and also the construction of the material installation [11].Material Absorbers have various factors that need to be analyzed, so an analysis will be carried out based on these factors to answer the problem statement and find suitable materials for the needs.Material PET has many advantages in its use in acoustic materials.The product used in this research analysis is the Ecoustic Dual Panel, which has a coefficient of 0.75 at a frequency of 1000.This material is easy to install using adhesives or joints, it can be easily shaped and has many patterns that can be adjusted to the needs of the room's characteristics.This material has good durability and fire resistance standards, and is also safe for health as it is nonallergenic and non-toxic.After being manually calculated, this material has been proven to be effective in optimizing reverberation time and noise The PET material also has many advantages when used as an acoustic material.The product used in this research analysis is the Ecoustic Dual Panel, which has a coefficient of 0.75 at a frequency of 1000.This material is easy to install using adhesive or joints, easy to shape, and has many patterns that can be adjusted to the characteristics of the room.It has good durability and fire resistance, and meets fire safety standards.The material is also safe for health as it is nonallergenic and non-toxic.

Fabric
This fabric material has a fairly good design, but it is less flexible because generally the material is fixed.In addition, this material has a high sound absorption coefficient of 0.72 at a frequency of 1000.This material is easy to install and can be attached using adhesive or even Velcro, but it is made of fiberglass which is not good for long-term respiratory and human health.The maintenance of this material is quite good, but it is vulnerable to water as it is quite absorbent, and it is also not very fire-resistant.In this study, this material is not suitable because the occupants work for hours and if this material is not good for respiration, it could cause health problems for them.This fabric material can also be used on ceilings and is as easy to install as on walls, but the with this material is its fiberglass base, which can lead to respiratory problems.

Wood (MDF)
This Wood (MDF) material is made of MDF, with a coefficient The (MDF) material can be used on the ceiling, but the installation of this material is quite complicated.It requires a lot of supporting frames, and when installed on the ceiling, it can be quite heavy and burden the ceiling or plafond.

Serat Polyester
This material has the same base material as PET, but there are differences in the composition of the material and its production.
In this research analysis, the material used is Acourete Board 230, which has a sound absorption coefficient of 0.4 at a frequency of 1000.The material is easy to install and maintain, durable, and has a fire-friendly reaction for the occupants.However, the material does not use recycled materials like PET and its effectiveness depends on its thickness.The design of this material is also easy to shape due to its flexible base material.For optimizing the reverberation time, this material has a significant impact and can absorb sound for the absorber material itself.
This material can be used for ceilings with the same ease of installation, but in some cases, it may require a frame for support when applying the material to the room.
Based on the comparison from Table 2 and Table 3, it can be concluded that PET and Polyester Fiber materials have a good level of safety for occupants.Meanwhile, Wood (MDF) and Fabric materials have aspects that are less suitable for this research, so the reverberation time calculation is only carried out on PET and Polyester Fiber materials to determine which material is more efficient in optimizing the reverberation time to maximize sound clarity and good acoustic in a SOHO apartment unit used for office or residential activities.4 , it can be concluded that the material that efficiently produces reverberation time in unit apartment C is Polyethylene Terephthalate (PET) because PET results in a reverberation time of 0.84 seconds.Based on the reverberation time calculation of the Polyester Fiber material, it does not meet the standard, only producing 1.41 seconds, which can cause the reverberation time to be too long and disrupt the clarity of sound during meetings.Further calculations will be carried out with different apartment configurations and types using PET material to confirm the above data.Table 5 is present the recap of all the simulation and result of reverberation time in all unit.

Design Implementation
The simulating the space with Autodesk Ecotect software to see how the room responds to sound reflections on potential sound sources, after that we see which parts are most affected by the sound reflections, after that the area will be calculated.the space that has been created and based on the number of areas (walls and ceilings) in the room, PET material will be applied which has been analyzed and calculated whether it meets the specified standards or not.After obtaining results that meet the standards, all materials and surfaces will be compared in ratios to obtain a room configuration that can be used for similar rooms.Based on Figure 6, calculations have been carried out on unit B and the results obtained from these calculations are 0.701 s, which is still within the specified standards, and also obtained material configurations of 4.85:1 and 1.71:1 for the walls and ceiling.

Unit Type C
Based from Figure 7 this unit is the type in this apartment building, with 11x6x5,4 dimension and two bedroom, this unit implemented the environment acoustics using PET Material for have standard result for meeting, material used in this unit is Ecoustics Dual Panel, Ecoustics Ceilling Flats, Ecoustics Print Plus.Ecoustics Dual Panel is for wall with 0,4 coefficient, Ecoustics Ceilling Flats is For Ceilling with the big 0.85 coefficient, and Ecoustics Print Plus is for Furniture in this case unit used for desk office.Based on figure 8, calculations have been carried out on unit C and the results obtained from these calculations are 0.82 s, which is still within the specified standards, and also obtained material configurations of 6.12:1 and 1.09:1 for walls and ceilings.

Unit type C2
Based from Figure 9, this unit is the type in this apartment building, with 10x6x5,4 dimension and two bedrooms, this unit implemented the environment acoustics using PET Material for have standard result for meeting, material used in this unit is Ecoustics Dual Panel, Ecoustics Ceilling Flats, Ecoustics Print Plus.Ecoustics Dual Panel is for wall with 0,4 Coefficient, Ecoustics Ceilling Flats is For Ceilling with the big 0.85 Coefficient, and Ecoustics Print Plus is for Furniture in this case unit used for desk office.Based on figure 10, calculations have been carried out on unit C2 and the results obtained from these calculations are 0.776 s, which is still within the specified standards, and also obtained material configurations of 2.4:1 and 1.43:1 for walls and ceilings.

Concluding remark
Based on the analysis that has been conducted by analyzing a building material through the application to a precedent study sample, it is stated that the use of absorber material can create good acoustic comfort results, providing significant results from the existing condition that does not enter the Reverberation Time (RT) standard category.After being treated with absorber material, the reverberation time in the room falls into the category of good acoustic space (standard).
Based on this discussion, the material that meets the aspects for optimizing reverberation time and sound absorption for absorber material is PET material, which has the following aspects: 1. Sufficient absorption coefficient to meet the functional requirements of a room.2. Practical material installation.3. Good maintenance and durability of the material.4. Resistant to fire, mold, and long-lasting.5. Material design that is suitable for the aesthetic needs of the room.
The use of absorber material can also make a room more private because it plays a significant role in absorbing sound from the inside, providing more privacy for workers, especially when the unit is used as a meeting or conference room.This way, occupants or workers do not need to worry about sound escaping from the room.
With these findings, the material configuration and installation of materials for each room that has been analyzed can be used in various SOHO rooms with the same or similar size and layout, with the use of the same materials and also the same configuration, all SOHO type apartments will have a level good room acoustics, contribute to sustainability, push the productivity of occupants by using materials that have been analyzed and calculated in this research.
This result of this research can be references for private sector or developers in designing apartments SOHO or lofts from material configuration and acoustics environments in order to achieve sustainable, healthy, and productive urban communities and cities.

Figure 1 .
Figure 1.Padina Residence tipe c & d Based from Figure 1.The Padina Residance SOHO apartment unit is an apartment with a SOHO concept that serves as a workspace (meetings, interactions, work, etc.) as well as a residence.The room has an area of 50 square meters (excluding the balcony).The floor material used is 40 x 40 terrazzo tiles, the walls are made of brick with plaster and paint finishing, and the ceiling uses 9mm gypsum board.This unit type has two large windows up to the ceiling and a door with dimensions of 1 meter x 2.1 meters.There is a unit available in the Padina Residence SOHO apartment, type C. The unit layout in the Padina Residance apartment is a double-loaded corridor type, where one corridor is flanked by two rows of apartments.

Figure 2 .
Figure 2. Simulation sound bounce at unit c

1 .
Unit Type A Based on Figure3this unit is the smallest type in this apartment building, with 4x8x5,4 dimension, this unit implemented the environment acoustics using PET Material for have standard result for meeting, material used in this unit is Ecoustics Dual Panel, Ecoustics Ceilling Flats, Ecoustics Print Plus.Ecoustics Dual Panel is for wall with 0,4 coefficient, Ecoustics Ceilling Flats is For Ceilling with 0.85 coefficient, and Ecoustics Print Plus is for Furniture in this case unit used for desk office.

Figure 3 .
Figure 3. Unit Detail Type A

Figure 4 .
Figure 4. Simulation of unit Type ABased on figure4, calculations have been carried out on unit A and the results obtained from these calculations are 0.722 s, which is still within the specified standards, and also obtained material configurations of 4.8:1 and 1.8:1 for walls and ceilings.

3. 4 . 2 .
Unit Type B Based from Figure5this unit is the type in this apartment building, with 6x8x5,4 dimension, this unit implemented the environment acoustics using PET Material for have standard result for meeting, material used in this unit is Ecoustics Dual Panel, Ecoustics Ceilling Flats, Ecoustics Print Plus.Ecoustics Dual Panel is for wall with 0,4 Coefficient, Ecoustics Ceilling Flats is For Ceilling with the big 0.85 Coefficient, and Ecoustics Print Plus is for Furniture in this case unit used for desk office.

Table 1 .
Coefficient room acoustic unit c (existing)

Table 2 .
Material conclusion

Table 4 .
Result type c