The goal of this research is to acquire any work items that are viable to be value-engineered and also can increase the value of a material [1]. Many concepts of implementing green buildings have provided various benefits in developed countries, but implementation is still largely not beneficial in developing countries, including Indonesia [2].

According to Law Number 28, 2002 concerning buildings, it is explained that each building has a different function. The number of 3-star hotels in DKI Jakarta in the 2014-2018 period has increased by 53.05% or from 213 hotels in 2014 to 326 hotels in 2018. Meanwhile, the number of hotels throughout Indonesia has reached 1,302 hotel units built [3].

The Facade is the outermost part of the building's architecture that reflects the image and expression of all parts of the building, it can even become the soul of the building.

The exterior will be the most critical and vulnerable to extreme and rapid weather changes. The composition of a façade, taking into account all its functional requirements (windows, doors, sun shading, roof planes) is principally carried out by creating a harmonious unity using a proportional composition, structured vertical and horizontal elements, materials, colors, and decorative elements. Other things that are no less important to get more attention are the proportion of openings, building height, the principle of repetition, a good balance of composition, and the themes that are included in the variations [4].

The use of the VE method will certainly be more valuable with a combination of the Green Building method. Based on the most recent research [5] that buildings and their construction consume 36% of the world's energy, and cause 39% of greenhouse gas (CO₂) emissions, therefore the façade design concept will be reduced by using the Green Building method to reduce the dangers of natural damage and is also environmentally friendly (Fig. 1).

Besides, it can also be seen that the percentage of external heat gain from the use of the façade is the highest load of the main cooling system which reaches 60%. Thus the facade can be optimized with energy-saving consumption using value engineering methods and green building concepts. The implementation of the green building concept can be applied by utilizing solar energy sources. Based PP. 79 of 2014 concerning National Energy Policy, the target of the new and renewable energy mix in 2025 is at least 23% and 31% in 2050. Indonesia has a large enough potential for new and renewable energy to achieve the primary energy mix target, as seen in Table 1 below.

Currently, the local government has installed as many as 24 power plants from new and renewable energy sources with a capacity of 354.08 MW from the total planning of 1,771.41 MW and has been operating in the 1^st semester of 2020 [6]. The application of a working system using VE and green building can achieve innovations in quality and cost efficiency and energy conservation obtained during planning until the value of benefits is calculated in the future. This research is a novelty with these innovative achievements that can reduce the use of electricity that comes from PV.

In the current construction world, finishing work on the outer wall (facade) as the outer side of a building is common and widely used. The use of a building façade is closely related to the concept of environmentally friendly buildings. For example, if a building uses glass as a facade material, it can certainly have a bad impact on the environment, where the effect of the reflection of sunlight from the glass material can increase hot temperatures and dilute the ozone layer as a protective layer of the earth and what happens if the entire building uses glass as a material. The facade will certainly add to the worse of the things mentioned above.

In this paper, the author will analyze the value engineering of the facade material with the concept of an environmentally friendly building. In Value Engineering (VE) problems in general, the obstacles that are often encountered include in the design process, correcting mistakes made by planners, or doing recalculation that has been done by planners, reducing process costs, reducing costs by reducing excellence or appearance, and quality control.

Green Building and VE in the facade work process have never been carried out, even though VE activities in the facade work process are very necessary because they can create a function of the work process stages and reduce construction costs to be more efficient overall without reducing the function of the material and space in the hotel building.

The application of this system can achieve innovations in quality and cost efficiency and energy conservation that are obtained not at the beginning of development but obtained during planning so that the value of benefits is calculated in the future.

The results of this study are as follows:

• Implementation of high-rise hotel building façades based on Green Building and VE can be seen in the implementation flow chart, where several factors influence cost performance which is the research variable as indicators of success and the achievement of hypotheses in facade work performance.
• From the results of statistical analysis, there are 10 (ten) factors that most influence the application of the Green Building and VE methods on facade work; 1. Project Feasibility Study, 2. Detailed Engineering Design (DED), 3. Cost Usage, 4. Data Analysis, 5. Functional analysis 6. Development Stage, 7. Cost Reduction / Reduction Cost, 8. Design Concept Selection, 9. Image Specifications, 10. Material and System Selection (Reduce / Select).
• After the value and function engineering was carried out through case study analysis, with the use of PV material as much as 100% (floor 1 to floor 10) from 2 sides of the facade wall (east side and west side) which can produce ± 1,050 KVA of electricity from PLTS, and can reduce the use of electricity from PLN by 991 KVA, of the total hotel electricity needs that reach 2,041 KVA can reduce PLN electricity use by 47.32%.
• The hypothesis of this research is based on the results of statistical analysis and case studies. It can be concluded and proven that the application of the Green Building and VE methods can improve the cost performance of high-rise hotel building façades.

This research can still be developed more broadly by looking at the other side of the green building aspect, of course with the same object or even a different object, but still prioritizing the green building aspect, especially in saving energy.

The use of PV materials in high-rise building facade components, if applied optimally, will produce optimal electrical power, besides that it is also an environmentally friendly material with reference to the green concept.