When designing buildings for sustainability, we create naturally ventilated facades and use local renewable materials. We leave roofing to the very end and end up using the same methods and materials.
With solar power and the climate of a site being powerful tools to enhance the living conditions of space, choosing the right roof for your building design is essential.
While choosing the right sustainable roofing method for your design, the following considerations can help make the process much easier:
Having covered the roofing materials in the previous article, the rest of the considerations are elaborated in brief in this article.
The concrete roof comprises natural materials such as sand, water, cement and so on. Materials that are derived from pre-used and discarded old concrete tiles can be recycled to form new tiles.
These tiles are an energy-efficient option due to their sunlight reflecting property. They are highly durable resulting in a longer life span for the tiles.
Cool roofs are a highly efficient method to reduce the overall internal temperature inside the buildings. They are designed to maximise solar reflectance and radiate absorbed solar energy.
They are highly energy-efficient and reduce air conditioning needs in the building. They are also known to improve indoor comfort and are cost-effective.
Some cool roof options are - Metal roofing, Asphalt or wood shingles, clay or concrete tiles and so on.
Insulated roof panels are fixed to provide maximum protection from the harshness of the climate. They are metal panels with steel skins attached to them, under which is an insulating foam core.
Roof gardens are an infamous energy-efficient option to keep the roofs cool at all times. With flexibility in their design, they can be custom-designed to fit the aesthetic and functional needs of each building.
Production of oxygen and reduction of overall carbon dioxide levels in space makes the air more breathable and reduces pollution. They keep the ceilings cool as no direct sunlight falls on the roofing itself.
Double skinned metal roofs are highly reflective and ventilated, making them an ideal choice for high-performance roofing. They are two metal sheets layered on top of each other with the provision of a central gap for insulation and vapour gap.
The heat is absorbed and then emitted back to the atmosphere consistently by natural convection. This hence makes an excellent passive cooling option for roofing.
The addition of water elements to the roof of buildings helps passively keep the building temperatures cool. The ponds are often supported with RCC slabs or metal reinforcement so it doesn't seep through the ceiling.
They are an effective feature for places that have low humidity and high temperatures. The roof ponds act as heat sinks that absorb heat from below.
Roofs are partially covered with glass or other transparent/translucent material to let in natural daylight into the building. This helps save overall energy costs during the day inside the building.
Operating windows could be added to the skylights to act as natural ventilators as well. Spaces that experience gloomy weather can make the most use of the skylights.
Solar PV Panels can be attached to the existing roof structures to enhance the energy efficiency of the building. Solar panels prove to be cost-effective in the long run.
They are also a perfect method to utilize the existing natural resource on the site in our favour. Solar tiles are a more aesthetic alternative to regular solar panels.
Wind catchers can be built along with the roof structure to let in natural ventilation into the buildings. They are designed to increase the speed of airflow.
Wind catchers have the ability to decrease the indoor temperature by 10 degrees. They are most effective in hot climates to create passive cooling inside the building.
The slope of the roof must take into consideration the climatic needs of the space.
Ex. A rainy or snowy climate calls for sloped roofs so that water or snow doesn’t stay stagnant and seep through the roofs into the building.
Maintenance and overall lifetime costs of the roofing system is important. This is mainly because roofs tend to be either inaccessible in some installations or have high repair costs.
They have to be entirely replaced in most cases, so choosing a durable alternative at the beginning will be a better solution.
The coating of the roof plays a major role in keeping the roof weatherproof. There are some aspects to roof coating, which when considered, can make them environmentally friendly:
i. Choose roof coating that is high in reflectivity.
ii. Prefer zero or ultra-low VOC coating.
iii. Check for LEED compliance of the coating material.
iv. Choose the roof coating kinds that are renewable every 10-15 years.
Light coloured roofing with high reflectance will make sure that only the required amount of sunlight is absorbed and most of it is reflected right back into the atmosphere. That makes them ideal solutions in areas with high exposure to sunlight.
Roofing is an aspect of building design, that when given the right amount of importance can increase the building’s energy efficiency by multiple folds.
Studying the local roofing techniques can often give us energy-efficient solutions to existing problems in the space.
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