Hot Outside, But the Roof Stays Cool? Discover Emak’s Home Strategy!

Keeping a roof cool in hot weather involves more than simply selecting the right roofing material. For architects, thermal comfort must be achieved through the relationship between building envelope geometry, opening orientation, airflow pathways, insulation layers, and the characteristics of the spaces beneath the roof.

Rumah Emak, designed by Pavilion 95 in Tangerang, is a residential project by architect Ar. Cahyo Candrawan, IAI, GP, and was selected as one of the finalists of the Steel Architectural Award 2024. Built on a 166 m² plot with a total building area of 116 m², the house demonstrates this approach through a residential design tailored to an elderly occupant. Conceived as a gift from a son to his mother, the house allows her to maintain an independent lifestyle while living close to her eldest child's residence.

Similar approaches can also be found in other finalist projects of the Steel Architectural Award 2024, including GOR Djarum Magelang, which addresses large-span roofing requirements; Raja Haji Fisabilillah International Airport, which responds to coastal climate conditions; and Mayora Head Office Canteen, which enhances spatial quality through its roof and ceiling design.

These projects demonstrate how tropical architecture principles can be adapted to different building typologies according to their specific requirements.

Understanding Rumah Emak and Its Occupants' Needs

Rumah Emak was developed in response to highly specific living requirements. The residence was designed for an elderly mother and a caregiver. Located near her eldest child's home, it allows the occupant to remain connected with her family while maintaining an independent living environment.

This context places clear spatial orientation, shorter circulation distances, and straightforward maintenance at the center of the architectural design.

1. Open Floor Plan for Easy Navigation

The spatial organization is designed to be intuitive and easy to navigate. Three bedrooms and two bathrooms are arranged along circulation paths with minimal intersections. The main bedroom, kitchen, semi-open terrace, staircase, and family room are connected through a shared circulation hub.

This arrangement reduces potentially confusing corners and allows the caregiver to monitor the occupant's daily activities more easily.

The upper floor accommodates two additional bedrooms, a multipurpose room, a bathroom, and a small north-facing terrace, while the ground floor remains the primary living area for the elderly occupant.

2. Family Room as the Center of the Design

The family room serves as the central element connecting functionality, natural lighting, and airflow. High ceilings and a void create a sense of vertical spaciousness within the relatively limited site.

Large glass doors connect the family room with the terraces and gardens at both the front and rear of the house.

When opened, these doors visually expand the interior while allowing air to circulate through the building. This relationship between indoor and outdoor spaces also reflects the principles of modern architecture, which integrate functionality, proportion, materials, and occupant experience into a unified composition.

Curved Roof Design That Enhances the House's Character and Performance

The roof of Rumah Emak serves not only as a protective element but also as a defining feature of its architectural identity.

The traditional gable roof is transformed into a curved surface with a radius of approximately 120 centimeters, creating a continuous building envelope that extends from the roof to the facade. This approach produces a simple architectural expression while strengthening the house's distinctive character.

To maintain this curved form, LYSAGHT® SPANDEK® OPTIMA profiles are applied to the roof and selected wall surfaces, ensuring a consistent linear rhythm across the facade.

Beyond its clean appearance, the roof geometry also considers building performance, including space for insulation, ventilation within the roof cavity, and rainwater drainage to help maintain thermal comfort.

A seemingly simple roof form also requires precise construction detailing. Panel modules, joints, support points, and drainage systems are carefully designed to preserve the roof's continuous appearance while supporting its performance in tropical conditions.

This approach demonstrates that effective roof design should not only establish a strong visual identity but also support the building's long-term performance.

Tips for Keeping the Roof Cool: Strategies from Rumah Emak

Thermal comfort at Rumah Emak does not depend on a single element. Instead, it results from the integration of roof design, ventilation, materials, and color selection.

1. Optimizing Natural Ventilation

Fresh air enters through glass doors, terraces, gardens, and lower-level openings. It then moves upward through the family room and void before exiting through skylights and upper openings.

This vertical airflow helps reduce the accumulation of warm air inside the house.

2. Using the Void as an Airflow Pathway

The void creates a sense of spaciousness while providing a vertical pathway for warm air to escape.

It also allows natural light to penetrate deeper into the interior, helping maintain thermal comfort without relying entirely on mechanical cooling systems.

3. Installing Insulation Effectively

A layer of rockwool insulation beneath the roof covering helps slow heat transfer and reduce noise from rainfall.

For optimal performance, the insulation should be installed continuously, without gaps at roof joints, wall connections, or skylight interfaces.

4. Choosing the Right Roof Color

Rumah Emak features a Gull Grey roof combined with an Off-White facade and natural-toned materials.

In addition to reinforcing the building's architectural character, roof color selection contributes to the overall thermal comfort strategy, particularly when considered alongside building orientation and the intensity of solar exposure.

Support Cooler Residential Roof Designs with the Right Materials

Material selection should respond to the spatial concept, building envelope geometry, and site conditions.

COLORBOND® Steel has been developed by BlueScope over the past 60 years for roofing and facade applications. Material options for residential projects can be evaluated based on profile characteristics, environmental conditions, jointing systems, colors, and maintenance requirements.

Various residential case studies demonstrate the relationship between building scale, roof geometry, material palettes, and climate responsiveness.

At Rumah Emak, strategies for keeping the roof cool are achieved through the coordination of a curved roof, voids, cross ventilation, upper openings, rockwool insulation, and spatial organization designed around the needs of an elderly occupant.

Every project has different orientations, roof configurations, and environmental challenges. Therefore, material specifications should be tailored to the design requirements and site conditions through technical discussions from the early planning stages.

Frequently Asked Questions (FAQ)

1. What are the key principles behind Rumah Emak's cool roof design?

The main principle is to integrate roof geometry, cross ventilation, voids, upper openings, rockwool insulation, and color selection into a coordinated building envelope system.

2. Why are voids important for thermal comfort?

Voids provide vertical pathways that allow warm air to move toward skylights and upper openings while connecting airflow between different levels of the house.

3. What are the main challenges of designing a curved roof?

The main challenges include determining the bending radius, panel modules, installation tolerances, overlap direction, drainage systems, fastening methods, and insulation continuity.

4. Why are sectional drawings important in designing a cooler roof?

Sectional drawings illustrate the relationship between opening heights, roof cavities, insulation placement, airflow pathways, and material junctions that may not be fully represented in floor plans.

5. How does roof color contribute to keeping a building cool?

Roof color influences the building's visual character and the surface's response to solar exposure. Its selection should be considered alongside building orientation, roof slope, shading conditions, and the overall facade composition.

Article Sources

Steel Architectural Award

References to the Steel Architectural Award 2024 finalists from the COLORBOND® website:

• GOR Djarum Magelang

• Raja Haji Fisabilillah International Airport

• Mayora Head Office Canteen

Related Articles from the COLORBOND® Steel Website

• Characteristics of Tropical Architecture

• Modern Architecture