A comprehensive guide to eco-friendly building in Bali, Indonesia

The Bali property market has exploded in recent times as it becomes a mecca for ex-pats, investors & Indonesians from neighbouring islands wanting to settle down or invest in a villa, and with this rapid rise in demand, the building cost has hit an all-time high.

The diversity of investors and homeowners has resulted in a big shift in architecture, with trends following those from Europe, Tulum (Mexico) and beyond. This shift in architecture has also meant a shift in building practices and the variety of materials used.

Some of these new building designs & practices are not always suited to the tropical climate of Bali, with intense rains during the 3-month rainy season (sometimes exceeding 1.7mm per year) and day after day of blisteringly hot days during the dry season places a lot of stress on buildings and the liveability of the properties, making it less sustainable for the long term.

But there are small changes you can make when designing & choosing your materials to make your next build more sustainable, both for the environment and for your hip pocket.

How we can implement passive cooling and save more energy

Bali is hot pretty much all year round with an average temperature of 28 C (82 F) and a humidity level hovering around 85-90%. With so much heat and humidity, it’s easy to reconcile with the idea of just adding more and more air-conditioner units to your property to help combat the heat. While this works, it comes at a cost to the environment, with power consumption producing tons of CO2 emissions and the use of HFC/HFO gas impacting the ozone layer.

While the use of air-conditioners will remain a staple here, we can implement some minor changes to the design to facilitate passive cooling. Passive cooling is an approach that focuses on heat gain control and heat dissipation in a building in order to improve indoor thermal comfort with low or no energy consumption and when it’s done right, it can be the least expensive means of cooling a home, especially in environmental terms.

We can achieve this control by either preventing heat from entering the building or by removing heat using natural cooling. Some common techniques include:

Solar Control

This is the use of shade in areas of high solar radiation. Large windows with direct sunlight, especially west facing, will heat your space very quickly. But with clever use of curtains, overhangs or trees, you can reduce the impact of solar radiation significantly.

Site design & orientation

We all know choosing the direction of your block of land is not always a choice, however, you do have control over the way you orientate your building to further minimize the impact of sunlight. Furthermore, by taking into account the concept of solar control, you can limit the need for measures in orientating your building, allowing you to build a space without sacrificing the design you want.

Beyond sunlight, you also have ventilation. When you’re building, you can take into account historical records of wind direction & speed in your area, and with a clever design, you can increase ventilation and create a cross breeze throughout your building, naturally cooling your space.

Thermal zoning within your building

When designing your space, the laws of thermal dynamics will always exist and the more you push against them, the harder it is to control the climate in your home or building.

In principle, heat rises, so rooms on lower levels are naturally cooler than those above. So when designing your space, having spaces that are more thermally insulated or have less solar radiation on upper floors will be easier to cool, while big open spaces on lower levels will naturally be cooler. Of course, introducing clever ventilation and cross breeze can help lower the effects but it will come down to your land and the orientation of your building.

Thermal insulation

This is a big one, and it revolves around the idea of using materials that are more insulating from the onset, helping lower the amount of heat entering the building as a whole, regardless of any of the above principles.

As technology improves so too do the options available. While houses in Europe or North America commonly use a combination of insulating materials, for example, windows that are double glazed and walls that might have 3-4 separate layers (brick veneer followed by a timber/steel frame, insulation in the walls and roof, and finally gypsum/plasterboard), these options are either not available, not economically viable or just don’t work here in tropical environments.

As a result, buildings in Bali generally resort to using traditional concrete (or Hebel), and while it has an acceptable level of thermal conductivity value, it’s far behind in advantages compared to some of the newer and better options that are also well-suited to tropical conditions such as geopolymer concrete. EcoCrete’s cellular geopolymer concrete offers significantly better thermal protection than traditional concrete, creating a naturally cooler interior, lowering upfront costs & drastically lowering ongoing operating costs. In addition to this, we need to really consider the damage traditional concrete has on the environment which makes its use unsustainable - you can read more about it here.

Sustainable Design & Materials

When it comes to your material design and the finishings, you also have a lot of control over the impact of your building on the environment. For example, using locally sourced products vs imported, or materials that require a lot of processing vs ones that are recycled/have minimal lifecycle impact.

One of the best parts of the recent building boom in Indonesia is the innovation that’s brought in by so many companies producing products that really put sustainable design at the front and center.

For example, in the interior design space, we have Space Available, which make beautiful furniture and art from recycled plastic, and Della Santa Studios which uses a mix of plastic and recycles material to make lightweight pots & tabletops for your home or office. In the concrete space, EcoCrete has set out to create a product that could be sprayed, cast or poured, effectively replacing traditional concrete in a range of applications while being carbon negative. And in the wood recycling space, there’s Kaltimber, a company that sources waste timber from all over Indonesia and re-purposes it into new products, drastically cutting down the need for rainforest timber.

While there is still a long way to go, the future is bright in this space and we can’t wait to see what happens in the next few years.

Building to last

The method of construction can make a big impact on its overall sustainability - a villa or building that requires less maintenance and lasts longer will be better for the environment overall and it’s something everyone should be striving for.

This starts with clever design taking into account the environment around your site. For example, is it low and prone to dampness and flooding, or is it surrounded by a lot of buildings, which means less ventilation and needs better thermal properties to fight the surrounding trapped heat?

Once you have identified factors like these, you can tackle them before the build and save any headaches later down the road.

Tackling rising dampness/water damage in Bali

Let’s take a look at one of the most common problems here in Bali - rising dampness/water damage.

The tropical climate is of course inherently damp, even during the dry season. If you then take into consideration that most buildings are built on thousand-year-old rice terraces that are designed to hold water and moisture, you are fighting what feels like a losing battle if you don’t take the right precautions.

First step: Installing adequate drainage

Start by installing adequate drainage across the space, starting from a foundational level. This might include raising the structure above the lowest point of the surrounding land or using dry wells (biopori) or agi-pipe (French drain) around the footings of your structure to draw water away and down into the ground.

If you plan to use a traditional concrete slab, the use of a plastic membrane cannot be understated, as this is a major point of water penetration that can result in water entering your building from below. Another alternative is to use EcoCrete’s geopolymer concrete, which is waterproof and can be used as either a sub-slab or even as a complete slab.

An alternative to using a slab is the use of piles and a raised concrete grid structure - allowing airflow below the building and keeping it high and dry, although this usually comes at an increased cost.

Second step: Looking at your choice of wall materials

The second step is considering your choice of wall materials, as it dramatically impacts how moisture enters your building. For example, traditional batako bricks absorb up to 35% whereas EcoCrete Greenblocks absorb less than 8%.

Final step: Coming up with a clever roof design

If you look at traditional buildings in Bali and Indonesia as a whole, you will see they have high-pitched roofs, designed to wick water away as quickly as possible. Of course, this won’t always work with the up-and-coming trends in architectural design, so it’s important to take your roof design into consideration and allow for adequate drainage to remove water as quickly as possible.

There are many different factors at play here and it’s important to identify as many of these as possible before you start to build and raise them with either your architect or builder before construction begins.

We can all do it!

Building sustainably in Bali is totally possible and as technology improves and new exciting products and building practices come to the local market, it’s easier than ever before. Just remember that you don’t need to implement everything here to be making an impact - perhaps just making a slight shift in the orientation of your building to allow for better ventilation and cross breeze, or choosing to build with geopolymer concrete that gives you peace of mind when you sleep knowing you’re less likely to wake up to peeling walls.

If you have any other tips and tricks that you have found work or that you want us to look at, maybe even have our R&D lab put together something special for your next project, let us know, we would love to hear from you!