Butwal Power Company Limited (BPC) Office Building

Client: Butwal Power Company Limited

Location: Buddhanagar, Kathmandu

Status: Completed 2017

Area: Plinth Area and 571.3 sq.m.; Total floor area: 5668.61 sq.m.

Services: Architectural and Interior Design

This is the first Hyperactive Office Building with Green Building Design features in Nepal. It has been tried to incorporate world class Green Building Technologies considering climatological condition of Kathmandu valley. Some components were modified considering local context. For example, treated air from Earth Air Tunnel (EAT) is used as pre-heated air to Solar Air Heating (SAH) Panels, rather than directly supplying to office rooms as it is used to in other countries. SAH panels are designed considering climatic condition of Kathmandu valley, especially high humidity content in air during winter. Even the SAH panels has been modified considering high dust particle content in Kathmandu air. An array of SAH panels (60 numbers) are installed producing 30 kilowatt of hot air supply into the building. The same solar panels is used as draft system to create pleasant breezing in rooms during summer season. Hybrid of Solar Electricity Generation System (4 kilowatts) and Wind Turbine (2 kilowatts) has been designed for charging electric vehicles, lighting common area (basement, staircase, corridor & toilet) and security system. Separate outdoor lighting units with photo-voltaic cells are used for exterior lighting system. Building is aligned east-west so that it will have south orientation. It is beneficial for maximum solar gain during winter and less penetration of unwanted harassing sunshine during summer. The summer solar exposure to the building is minimized by placement of stairwell and restrooms at west part of the building.

However, EAT has been used for cooling of the building during summer, as it used to in other countries.

World class energy efficient practices have been used in the building. Double Glazed Windows is used to prevent heat loss from the building. Extruded Polystyrene Board is used to protect heat loss through wall and roof. In addition to the use energy efficient LED lamps, various types of light sensor devices has been installed. Another major energy saving measure adopted in HVAC (Heating Ventilating and Air-Conditioning) system are energy efficient VRF (Variable Frequency) type air-conditioning system and air handling units with ERV (Energy Recovery Ventilator).

In toilets and bathrooms, cistern with 'dual flush valve' and waterless urinals are installed in order to reduce usage of potable water by 30%. 'Anaerobic Filtration System' in combination with 'Root Zone Treatment System' is adopted to recycle waste water from toilets, bathroom and kitchen. Gray-water produced from this system is used for irrigation of plants and washing vehicles.

Rainwater Harvesting System of capacity of 70,000 liters is installed and overflow from the underground water tank is connected to the Underground Water Charging System.

Major portion of terrace roof is covered with roof garden, which acts like and heat insulation layer and will contribute to reduce heat island effect. Adhesives, paints, carpets and sealable with VOC are not used in the Project in order to prevent contamination of indoor air during operation of the building. In order to improve Indoor Air Quality of the building; Treated Fresh Air System (TFAS) is incorporated in HVAC system.

There is a provision of store at basement for collection of recyclable materials like paper, wood, metal and plastic.

Apart from environment friendly and sustainable design features of the building, it is designed to be earthquake resistance of 8 rector scale. Better earthquake resistance has been achieved by working out stable configuration of the building and provision of shear wall at ducts which are adjacent to columns.

The building is also designed as per Vaastu Shastra.