BCA Green Mark (Ape On Earth‘s Household Edition)
Last Revised: 27 Jul 2022
Disclaimer: All views expressed on BCA Green Mark (Ape On Earth‘s Household Edition) are my own. It is not intended to constitute or be relied upon as professional advice. You should consult a Green Mark Accredited Professional if you require professional advice.
References were made to following BCA documents in some sections of this article:
Dear reader, at Ape On Earth, I always begin a post by asking, does Climate Change matter to you? If you’re unsure, consider reading Blog Post #1 (5min) to find out about your inclinations before you return. And please know I appreciate it so much if you do, it literally means the world 🙂
This article is very long, so I suggest you skip to the headings that catch your fancy. But if you desire to maximise your return on investment (ROI), I challenge you to take it all in!
Why use BCA Green Mark (Household Edition) by Ape On Earth?
First and foremost, because Climate Change matters.
The world is legally bound by the Paris Agreement to limit global warming to well below 2, preferably to 1.5 degrees Celsius, compared to pre-industrial levels.
The world also has to reconcile the science-based Global Carbon Budget, which specifies that the world can only afford to emit a further 300-500 billion tonnes (Gt) CO2 from the start of 2020 (based on >50% likelihood of limiting warming to 1.5 deg C). This is an absolute budget, not an annual budget. There will be no other carbon budget. And there is no other Earth. (#noplanetb)
Now observe the graph below.
Source. Annual mean temperature in Singapore from 1948 to 2019 (Data based on climate station)
According to weather.gov.sg,
“Mean surface air temperature has risen by an average of 0.25°C per decade between 1948 and today. The upward trend is approximately double the trend in global temperatures, which occurred at a rate of 0.12°C per decade from 1951-2012.” “The higher trend over Singapore may have been due to the urbanisation, and could also be influenced by regional variations in the man-made global warming effect.”
In Australia, max temperatures recorded as recently as 2018, have been observed to have risen high enough to melt roads and cause transport infrastructure functionality issues.
Therefore, it is imperative that we design, and/or retrofit our households in such a way to defend against the looming effects of Climate Change, and ultimately preserve safe and comfortable living conditions.
Still need more reasons? My pleasure 🙂
- Sustainable cities and communities (UN SDG #11): Broadly meet the targets set out by UN SDG #11. Make cities and human settlements inclusive, safe, resilient and sustainable.
- Carbon Mitigation: Do your part to fight Climate Change when you find all ways to decarbonise. You are helping even by just systematically reducing your monthly energy usage. Your contribution puts less strain on our limited Renewable Energy (RE) resources, as we embark on a very challenging energy transition away from fossil fuels (mostly natural gas).
- More power stress to cooling systems: Referencing the popular Mitsubishi Electric Starmex split-type air conditioner operating instructions, the guaranteed operating range of the outdoor unit specifies that dry bulb outdoor temperature should be kept between 21 and 46 deg C. Also, it states that, “When the outside air temperature is high, the cooling effect may not be sufficient.” Rising temperatures will add stress to our existing installed cooling systems.
- Recurring cost savings: Any improvements you achieve in energy and water efficiency instantly reduces your monthly utility expenses. Straightforward.
- Return on investment (ROI) on your property: “BCA’s 2016 survey on green buildings also found that over 90% of the homeowners understood the benefits of green buildings, and more than 70% were willing to pay 3 to 4% more to own a home in a green development.” (source) Also, “An independent review of BCA’s Green Mark scheme carried out in 2019 assessed the total lifecycle cost across both residential and non-residential buildings. The study affirms that Green Mark certified buildings would be able to reap net positive savings throughout its lifecycle and the energy savings outweigh the upfront investment cost.” (source)
- Climate-responsiveness, health and well-being: Reduce heat gain into the buildings and improve natural ventilation. Improve indoor environmental quality. Guard against a fatal combo of high temperatures and high humidity, and guard against the failing of the sweating mechanism of the body that helps it naturally cool itself, as well as other effects of heat-related morbidity (illnesses) and mortality (deaths).
- Wayward building professionals: What if I told you that I can cite Singaporean residential developments that TOP as recently as 2017, that have fallen victim to poor building design? What if I told you that I witnessed people I know having to live with the mistakes made by so-called building professionals for the next 99 years of their property lease period? Are you so sure your building was well built? Why not read up just a little more so you can stand up for your rights?
Or perhaps you’re just a freedom pirate at sea (just kidding), then be sure to check out the following sections further in this article, to take full advantage of Singapore’s natural weather resources:
- Harness the Sun – Solar PV
- Master The Winds – Promote Cross Ventilation
This article leaves no man behind, pirate or not!
If we do this right, nobody loses.
Why the need for BCA Green Mark (Household Edition)?
The BCA Green Mark Certification Scheme, launched in 2005, is a nationally and globally recognised green building rating system. According to a 2020 media release by BCA,
But the Scheme was designed for entire buildings, NOT FOR HOUSEHOLDS.
According to 2022 data by Emporis, there are 11,287 low-rise and high-rise buildings in Singapore, out of a grand total of 12,375 buildings. It’s important to note that the high-rise building category excludes skyscrapers in Singapore. Even then, just adding up the low-rise and high-rise buildings in Singapore already accounts for 91%* of Singapore’s buildings.
* I have not been able to find data from singstat to reveal how many buildings in Singapore are residential. Do take note that I am looking for data on the number of buildings, not units/properties/dwellings. However, if you have a quick scroll through the data by Emporis, you will find most of the low-rise and high-rise buildings are residential buildings.
If my assumptions above are not too far off reality, and if that much of Singapore’s built environment is being made up by residential units, it strengthens the case to dedicate resources towards a BCA Green Mark (Household Edition), that could help to extract the sections from the main Scheme with the most potential for impact through DIY or professionally outsourced implementation in households.
Interior Designers (IDs), Contractors, and Residential Facility Managers could also be regulated to reference the official guidelines in BCA Green Mark (Household Edition), should it be realised one day. The BCA Green Mark (Household Edition) can also provide an opportunity for all Singaporeans to develop a deeper appreciation of the original Scheme. As they say, every bit counts!
Fun fact: All new and existing buildings undergoing retrofitting (including major change to the cooling system) are required to be assessed under the BCA Green Mark Certification Scheme. However, not all buildings are eligible for assessment. As of the date of this article, the scheme does not apply to office interiors, retail interiors, or other interior fit out projects. Perhaps more needs to be done to address this gap moving forward.
Don’t forget about water efficiency
Fun fact: According to a CNA article,
I will not elaborate too much on water efficiency in this article, if only because I feel that PUB has done well in Singapore to push on this front, and absolutely not because it is not important.
Source. R&D on the water loop by PUB
PUB’s R&D work is centred on the water loop shown above. In my opinion, NEWater is by far Singapore’s crowning jewel for its circular economy ambitions. Onwards and upwards!
Since as early as 1 Apr 2017, under the nation’s mandatory Water Efficiency Labelling Scheme (WELS), Singaporeans would not have had much choice in their next purchase of a water fitting except for a water-saving one.
Also Singapore has piloted the Urban Water Harvesting System (UWHS) to recycle rainwater for non-potable uses and help mitigate flood risk by releasing stormwater at a slower rate.
However, if your household is still using older non-water-saving fittings, consider contacting PUB for help to install thimbles for taps and showerheads. For enquiries, call PUB’s 24-hour Call Centre at 1800-2255782. Or if you prefer, you can fill in an online request form for a Water Saving Kit (each kit consists of 4 thimbles for taps and 2 thimbles for showerhead) from PUB’s website.
Mastering Singapore’s weather
(not adapted from BCA Green Mark)
Source. Singapore’s sun path diagram by Gaisma
In Singapore, being a tropical island close to the equator, we get 12 hours of sun a day. According to data from Changi Climate Station, daily temperatures typically range between 24 to 32 deg C, and mean annual relative humidity is 83.9%.
But in 2022, there were days where max temperatures of 35 deg C were recorded. Try to pay closer attention to your household temperatures and relative humidity levels moving forward. It’s only gonna get hotter.
- Temperature: SS 553 stipulates that air temperature should be kept between 23 – 25 deg C. Several articles, like this one by DBS, suggest that Singapore should try to maintain a temperature of 25 deg C at home if you’re using an air-conditioner.
- Relative Humidity: SS 553 stipulates that the average relative humidity level should be no more than 65% for buildings designed to SS 553/554, or no more than 70% for all other buildings. Too high, higher risk of virus, fungi, mould and mildew. Too low, higher risk of electrostatic discharges, therefore try to keep RH above 30%.
I assume most of us do not actively track relative humidity levels at home unless you’re a photographer who cares about his sensitive gear or a rare wine collector.
But do take note that higher relative humidity levels do play a part in multiplying thermal discomfort, and increase the risk of heat-related morbidity (illnesses) and mortality (deaths).
However, just maintaining the household temperature near 25 deg C in Singapore is plenty good enough for most of us, on most days.
Also don’t forget that often the secret to achieving personal thermal comfort, perhaps also the simplest to do, is to choose light breathable clothing.
Choose high energy efficiency appliances
(Save on utility costs and help to put less strain on our limited Renewable Energy (RE) resources)
(adapted from BCA Green Mark RB: 2016, and NEA’s “Resource Efficiency Guide for New Home Owners”)
CNA/Talking Point has covered this subject very well in their article, “10 ways to slash your bill as water and electricity prices rise”. I appreciate that they start off by calling Singaporeans to be aware of the top energy guzzlers in their own household. This is critical especially since each household may use energy quite differently.
Source. Singapore’s Household Energy Consumption Profile
From the above household energy consumption profile, it’s useful to note that three-quarters (75%) of the electricity is used to power just three appliances:
- Air-conditioner (36%)
- Water heater (21%)
- Refrigerator (18%)
It’s obvious that most of us will fall into that average statistic, so pay closer attention to these appliances if you use them!
Quick tips* on choosing energy efficient appliances:
*ranked in order of highest to lowest typical household electrical usage
- 5-ticks Air-conditioner
- Electric Instantaneous Water Heater, Gas Water Heater, or a Heat Pump Water Heater
- 4-ticks Refrigerator
- 5-ticks TV
- 3-ticks LED light bulbs
- 4-ticks Washing Machine
- 5-ticks Clothes Dryer
- Brushless DC Motor For Mechanical Ventilation (instead of AC motor)
- Magnetic bearing for oil-free and frictionless operations
In general just aim for the highest number of ticks available at the time of purchase!
Spotlight: Best practice for choosing your air-conditioner system
(I put heavy emphasis on air-conditioner systems because it’s often the biggest energy guzzler (36%) in modern households)
Air-conditioner spec sheet sample:
(It may take some effort to find the full specs online. Some resellers choose to only publish limited specs, and sometimes even publish the wrong specs on their websites. I recommend that you compare at least 2 sources.)
Just pay attention to the cooling capacity and rated power input/consumption as circled below.
- Step 1: Measure the enclosed area of the space to be air-conditioned.
Eg. 15m2 Master Bedroom
- Step 2: According to NEA’s “Resource Efficiency Guide for New Home Owners”, “…a useful rule of thumb is to divide the area of the space to be air-conditioned by 5.” Cooling capacity required in kW = Total area to be air-conditioned [m2] / 5
Eg. 15m2 / 5 = 3kW
- Step 3 (optional): Convert cooling capacity required in BTU/hr = Cooling capacity required in kW * 3412
Eg. 3kW * 3412 = 10,236 BTU/hr
- Step 4: Select an air-conditioner system in the market with the most number of ticks, but also has a designed cooling capacity that exceeds your kW value calculated in Step 2, or your BTU/hr value calculated in Step 3. Both cooling capacity values are equivalent and are supposed to be used interchangeably. But in reality I found that retailers occasionally like to round up BTU/hr figures to the nearest thousand, so you might shortchange yourself if you’re not careful. My advice is to just stick with using kW values.
Eg. For a 3kW or 10,236 BTU/hr cooling capacity requirement, you may discover that there may be no 5-ticks single split system yet (Feb 2022) that can meet your requirements. The most energy efficient single split air-conditioner that could meet the needs of your 15m2 Master Bedroom is a 4-ticks, 3.5kW or 12,000 BTU/hr cooling capacity model. It’s not 5-ticks, but that’s just reality.
- Step 5: Calculate your break even period and ROI.
Let’s say you are currently using an old 2-ticks model with the same cooling capacity as the new model you’re considering, of 3.5kW or 12,000 BTU/hr. Compared to the previous 2-ticks model which has a rated power input/consumption of 1.02kW, this new 4-ticks model has a rated power input/consumption of 0.81kW. You save $167 a year (based on 8 hours daily usage, electricity tariff of 27.22 cents/kWh). The break even period of this ~$1260 (Feb 2022) investment is about 7.5 years. Quite long! And I know how you feel! But again, that’s just reality. Perhaps more zero or low interest financing options can be introduced to lighten the upfront costs and urge households to make this transition!
- BUT WAIT! Let me give you a real life example!
You might be surprised that your household has been pre-installed with air-conditioner systems which have designed cooling capacities that are over the best practice requirements. Someone I know has a 11m2 Master Bedroom. The developer pre-installed an older 2-ticks single split model which has a cooling capacity of 3.5kW or 12,000 BTU/hr. Using formulas from Steps 2 and 3, the best practice cooling capacity required should be 2.2kW or 7,506 BTU/hr. Currently, the most energy efficient single split air-conditioner system in the market that can meet those needs is a 5-ticks, 2.5kW or 9,000 BTU cooling capacity model. Compared to the previous 2-ticks model which has a rated power input/consumption of 1.02kW, this new 5-ticks model has a rated power input/consumption of just 0.51kW! You now save $405 a year (based on 8 hours daily usage, electricity tariff of 27.22 cents/kWh). The break even period of this ~$1180 (Feb 2022) investment is now only 2.9 years!
- Conclusion for air-conditioner systems: The real life example above proves that one should probably take a second look at your household’s existing air-conditioner systems and work out your own requirements based on best practices. DO NOT rely on loose advice by sellers alone as they may recommend a higher cooling capacity model than you actually need. Annual savings can be very significant and beyond the break even period, you will be putting all that extra cash in your pocket!
Bonus: If you live in a 1-, 2- or 3-room HDB household, do take advantage of the Climate Friendly Households (CFH) Programme, which offers up to $225 in e-vouchers to offset purchases of energy and water efficient appliances!
If you would like to learn more about other ways to select the best appliances for your household, I recommend reading the section on “Buying Energy & Water Efficient Appliances” in NEA’s “Resource Efficiency Guide for New Home Owners”. The guide is well supported by graphics and is very easy to follow.
Use a Lighting Power Budget
(adapted from BCA Green Mark: 2021, EE Section)
According to NEA’s “Resource Efficiency Guide for New Home Owners”, lighting typically accounts for about 4% of energy use in Singapore households. This percentage may be much higher if your household is not using LED light bulbs, and as much as 6-7 times more if your household still uses incandescent light bulbs.
By now it should be common sense that one should be using LED lighting fixtures as much as possible in Singapore. According to NEA,
“All Light Bulbs Sold In S’pore To Be Minimally Of LED Efficiency Level From 2023.”
The gains from a longer lifespan and electricity savings often outweigh the additional upfront costs. In Singapore, there’s little reason to use any other type of lighting fixture in our households, unless for very specialised reasons.
Perhaps one claims there’s an advantage in using incandescent light bulbs because they provide energy output as heat, aside from light. But I have to ask,
“Singapore not hot enough for you is it?”.
Or perhaps one claims that LED light bulbs cannot produce the warm tones of incandescent light bulbs that you have grown to love, but did you know that LED light bulbs come in all sorts of colours these days? Including Warm White (2700K), which is the colour output of your favourite incandescent lamp?
That said, the lumen output per watt, or luminous efficacy of an LED light bulb is different when compared with other types of light fixtures.
For example, according to The Lightbulb Company, a 4W LED light bulb outputs the same amount of lumens as a 25W incandescent light bulb.
Essentially, you could theoretically use 1 LED light bulb to output the same amount of perceived brightness as 6 incandescent light bulbs!
In any case, if you still insist on using non-LED lights at home, fine. But you will discover that using the Lighting Power Budget table below will be a bit more of a hassle. So why not save yourself the trouble and consider a change?
The Lighting Power Budget table below serves as a guideline that suggests an upper limit on the lighting power per square metre of space, depending on your household space type. The values are adapted from the original Lighting Power Budget table in the Green Mark Scheme.
It is important to note that using the budget below only focuses on capping your electricity consumption for your lighting design of each space type. Therefore, it does not mean that the perceived brightness will be ideal for the space type if you installed lights that are low quality and produce low lumen output per watt. Recall how a 4W LED light bulb outputs the same amount of lumens as a 25W incandescent light bulb. Long story short…purchase reasonable quality lights that can produce reasonable lumen output per watt. Just by choosing LED lights alone would help to avoid such issues. If you do it right, you may even have less lights to replace so in the long run, you save even more.
- The higher the value in W/m2, the brighter the light should be, when perceived by a person standing in a square metre of space with the light source overhead. For example, for a living room space of 3m2, you will need to cap lighting power to 24W (3m2 * 8W/m2) or below, to achieve GOLD standard. It’s your choice whether to opt for 1x24W LED Ceiling Light, or 2x12W LED Ceiling Lights spaced further apart, or even 2 parallel tracks of 3x4W lighting fixtures. So long as they add up to 24W within 3m2 of space, the sky’s the limit! There’s really no need to be too stringent about achieving the exact numbers listed in the table above and if you’re unsure, you can play it safe by buying lighting fixture(s) with a combined watt rating that is slightly higher. And please save your money, you don’t need to specially go out and buy a lux meter just to do this. And if you really must, you can just download a lux meter app on your phone.
- For space types that are not listed in the original Lighting Power Budget table in the Green Mark Scheme, I have selected the nearest match in order to provide my recommended values. For example, to provide recommendations for “Living Room”, which is not present in the original table in the Green Mark scheme, I have chosen “Multi-Purpose Hall” as the nearest match in order to provide my recommended values. Where there are multiple close contenders for matches, I have defaulted to select the highest value to provide for a safer margin of error.
- Try to avoid designing for a value below the SLE standard, or else safety, productivity and/or comfort levels may drop. You also don’t want your home to resemble a horror scene, do you?
- Try to avoid designing for a value above the SS530:2014 standard, as you may not observe any gain in safety, productivity and/or comfort levels. You will be simply wasting energy. And why would you pay extra to try and reproduce the sun at home? Are you trying to blind your guests?
- For readers who are building a new home and you’re engaging an ID or contractor, you can consider showing them the table and request them to design your lighting setup according to the standard of your choice!
Use task lighting
(currently not covered in BCA Green Mark)
Ever find yourself having to switch on all the overhead lights in your room just to do work on your desk in one small corner of the room?
Such scenarios call for task lighting! For example, you could retrofit your desk with in-built task lighting with replaceable light fixtures. The lighting should be specially directed at your work area so as to reduce your overall lighting power needs. Also, if you’re engaging an ID or contractor to custom-built your workstation, you can request for integrated task lighting!
I did find a reference to task lighting buried within the “Energy Efficient Interior Design Tips” section on NEA’s website.
It officially recognised the benefit of Task Lighting in Households but did not go far enough such that objective results could be engineered and reproduced in similar fashion as when utilising BCA Green Mark’s Lighting Power Budget.
This article explored “the energy saving potential and user behaviour towards task lights in two office spaces in Malaysia; one is daylight assisted, and another is the conventional design of full reliance on the overhead electrical light.” They found that
“Non-Daylight assisted task light office design saves up to 33.39% of lighting energy.”
And if your room has a window, you can try to position your desk closer to the window to receive daylight assistance, further reducing your lighting power needs during the day. The same article above found that,
“Daylight assisted task light office lighting design saves up to 78% of lighting energy.”
And so my dear readers, consider installing special task lighting at areas where you spend extended periods of your day with minimal movement requirement. If done right, you will improve your productivity and comfort, while saving electricity on excessive use of overhead lighting in your room.
I also hope that an official section on task lighting can be considered to be included in the next revision to the BCA Green Mark Scheme.
Harness the sun – solar PV
(adapted from BCA Green Mark: 2021, Re Section)
In Singapore, a tropical island close to the equator, we get 12 hours of sun a day. That’s a lot of Renewable Energy (RE) we ought not to waste!
The BCA Green Mark: 2021 does take into account,
This includes the
“supply, installation and commissioning of solar PV or thermal systems”.
So if your home has access to a solar-ready roof, be sure to check with your favourite local Green Electricity Contractor on how you can set up your own rooftop solar and immediately save you on energy costs.
I do not want to be accused of affiliation to any corporation, so just do a quick online search for “Solar for Landed Properties Singapore”, and you should find ready options.
Again, let me stress that you would want to be careful of companies who are #greenwashing. That said, regardless of which contractor you choose, it’s clear you already carry a spirit for positive change, and I thank you.
For readers who do not have access to their roofs at home, don’t fret. After all it’s more important you have a roof over your head, than access to it!
That said, we can still do our part by subscribing to a local Solar or Green Electricity Plan offered by a producer/retailer which has made public commitments to invest in RE infrastructure, whether locally or overseas. At least these guys put money where their mouths are. The other producers/retailers, I take a risk but I will call them out for #greenwashing. (feel free to prove me wrong, I would be relieved if I was.)
Read my article, “How to support Renewable Energy (RE) FROM Singapore?” to help you make your decision!
Master the winds – promote cross ventilation
(adapted from BCA Green Mark: 2021, Hw Section)
Few of us would disagree that prior to one making a political decision, one would be better off knowing which way the wind blows.
But before one can ever hope to achieve effective cross ventilation through your home, one’d jolly well first know which way the wind blows! ^^
And to do that we have to reference Singapore’s wind rose diagram, as below.
Source. Singapore wind rose diagram
If you’re struggling with the diagram, let me try to assist. In short, the bulk of Singapore’s wind tracked over a year is blowing from either the North/North-NorthEeast, or South directions, and at an average wind speed of 2.65m/s.
Fun fact: SS 553 stipulates an air movement speed of no more than 0.3m/s. Usually, 0.2m/s is considered ideal. Slightly higher speeds and the paper on your desk starts to experience lift and your work comfort may be affected. Even higher speeds and the indoor dust begins to disperse and turn into a source of discomfort and a potential health hazard. But of course, this factor is ultimately subjective and you can afford to experiment with it within your personal occupant space, as long as it does not affect other people in your immediate surroundings.
So if your home happens to have opposing openings generally facing the north and south, try to keep both these facings open and unobstructed, to promote cross ventilation.
Avoid including major structural bends in the crosswind’s pathway for maximum flow.
And remember, you need to open up BOTH opposing facings. It won’t work if you just open up one.
And it’s like free mechanical ventilation, so why not?
Fun fact: To score points on effective cross ventilation for Residential Buildings Non-Air-Conditioned functional spaces under the BCA Green Mark: 2021 Scheme,
“70% of habitable areas to meet the Area weighted average wind velocity of 0.6m/s.”
Install automated controls (smart home)
(adapted from BCA Green Mark RB: 2016)
If you count yourself amongst those who unintentionally struggle to turn off appliances when not in use, perhaps you can consider installing automated controls. Not many excuses left for wasting electricity these days ^^.
Be sure to check out YouTuber MADS “Smart Home Tech” playlist for inspiration. It’s actually not that difficult! Non-Affiliation Disclaimer: I am not endorsed by, directly affiliated with, maintained, authorised, or sponsored by MADS.
Now I would like to add on a few general tips of my own for those who are keen to embark on their home automation journey:
- Go for more well known smart home brands so there’s less risk of the company going defunct and leaving you with no means to receive future product support. It will be a complete waste of your time and efforts.
- Use a Schedule Design Approach if you unintentionally struggle to turn off appliances. For eg. Set a Schedule to auto turn off all lights after 10pm, or set a Schedule to auto turn off your air-conditioner two hours earlier than the typical time you wake up every morning. It’s relatively cool in the early mornings anyway and the existing cool air in the room is usually good for another hour or two. There are even others who claim, “One of the things that worked for me was that I can leave the air-con on for about two hours, and then I set the timer to switch it off”. If that works for you, even better still as you save on a lot more electricity.
- Use a Remote Design Approach if you struggle to manually turn off appliances due to some physical distance between you and the on/off switch. For eg. If you are currently on your bed and done with your night reading and you wish to turn off all your room lights without having to leave your bed to reach for the light switches on a far off wall.
- Use an Occupancy Design Approach for common areas that are seldom in use. For eg. Auto on/off the corridor lighting when occupancy is detected, after which it will auto turn off past a preset duration. You can opt to install motion sensors if the occupant is NOT expected to remain stationary at work in the area of detection. For eg. motion sensors are less effective in toilets, especially when you consider someone would be relatively stationary for a period of time when performing number 2. Important to note that the operational characteristics of occupancy sensors are slightly different from motion sensors.
I have to admit that home automation has been one of the most fun home retrofit projects that I embarked on. And so I hope that you too will find the same fulfilment I did!
Don’t go too overboard though, this project can quickly turn expensive!
It’s worth noting that there’s a fine line between automating for saving electricity and automating for laziness at home. While I am clearly in support of the former, there’s no crime in the latter ^^
Install door and window seals
(currently not covered in BCA Green Mark)
Many of us worry that our biscuits will go stale quickly when not kept in an airtight container. Yet, perhaps because we do not suffer the same fate as our biscuits, many of us do not see the need to seal our doors and windows at home ^^
It is important to know that by not doing so, we allow cooler air inside our enclosed rooms to leak out, and we end up causing our household cooling systems to work harder which leads to an increase in energy consumption.
Don’t believe me? Approach your nearest door, lay your head down on the surface of your floor, and observe how big the air gap is. Told you so.
Most door bottom gaps are approx. 15mm or less, but that’s significant if you consider the continuous air leak volume.
According to Arlington Air Conditioning Services,
Unfortunately, I do not have the resources to set up a controlled test environment to confirm the above claim. However, don’t let that discourage you from implementing this step. Aside from the bad English, it’s pretty obvious that the logic behind the advice is sound.
And besides, this is one of the cheapest solutions to implement and will help you to passively save on electricity in perpetuity.
I do not want to be accused of affiliation to any corporation, so just do a quick online search for “Door Window Seal”, and you should find plenty of local options.
You can save more if you DO NOT choose variants with automatic seal mechanisms, as they will be obviously far more expensive to manufacture.
And now that you have your seals installed, you can also count on a bonus reduction of pest entry and improved noise isolation. One of the best deals ever if you ask me! ^^
I hope that the electricity saving benefits of Door and Window Seals can be officially tested in a controlled environment and if proven, then perhaps be considered to be included in the next revision to the BCA Green Mark Scheme.
Demand Low-E glass for external facade windows
(adapted from Code On Envelope Thermal Performance For Buildings: 2008)
According to our Code On Envelope Thermal Performance For Buildings: 2008:
“The RETV (Residential Envelope Transmittance Value)…takes into consideration the three basic components of heat gain through the external walls and windows of a building. These are:
i. heat conduction through opaque walls,
ii. heat conduction through glass windows, and
iii. solar radiation through glass windows.”
In general, the lower your building’s RETV value, the more heat resilient it will be.
Fun fact: The Code states that,
“For the purpose of energy conservation, the maximum permissible RETV has been set at 25 W/m2.”
However, one may go even further with BCA Green Mark: 2021, EE Section, and qualify your residential building for Gold+ (22 W/m2), or Platinum/SLE (20 W/m2).
Lowering your building’s RETV will also help to lower the Mean Radiant Temperature (MRT), which is a key factor influencing overall thermal comfort.
Do note that MRT is different from Air Temperature (or Dry Bulb Temperature) in that it NOT ONLY considers the cooling/warming effect you get from contact with air in your occupied space, but it also considers the radiant cooling/warming effect you get from all other surfaces in your occupied space, such as your room windows, operating oven, etc.
In Singapore, an unofficial general rule of thumb is to design a building with MRT that is no more than 3 deg C above the air temperature. For badly designed buildings in Singapore, MRT can be measured to be as high as 10 deg C more than the air temperature.
According to Architect Magazine,
And that is why it is crucial that we remember that not all glass is created equal.
To decide which type of glass is best to use in Singapore, one must understand how to utilise the U-value of glass.
According to Wikipedia,
In general, the lower the U-value of a material used for the external facade of a building, the less the material will facilitate transfer of the sun’s heat into that building, therefore saving you electricity on air-conditioning needs and improving natural thermal comfort throughout the day.
According to EN 673 standard, Low-E type glass is typically rated with U-values of 1.8 W/m²K and below.
And yet, I can cite residential developments that TOP in Singapore as recently as 2017 that installed external facade windows using glass with U-values above 5 W/m²K! That’s almost three times the U-values of Low-E glass, even though they were invented as far back as 1981!
Hey, you professionals (you know who you are)…do you think Climate Change is a joke? Doesn’t mean something is not yet sufficiently regulated or illegal, means anyone should go ahead and deny one’s country the best.
Last warning: Property Developers/Architects/Building Contractors/Building Material Traders/Manufacturers all better wake up your idea.
Sorry…had a moment there. It’s just difficult to stand by and witness people you know having to live with the mistakes made by so-called building professionals for the next 99 years of their property lease period. Forgive me.
So my dear readers, have a guess at what is going on here? A quick search online for “Low-E glass Singapore” yields plenty of results that one could easily select from the myriad of local glass suppliers to build heat resilient buildings for our fellow Singaporeans to reside in. And yet, why isn’t this the case? Why have our professionals seemingly forsaken us?
Then, some of you might say,
“All is not lost! Why don’t we install solar films onto our existing windows to reduce solar transmission?”
A good suggestion, but let me first refer you to a “Proof of Technology Experiment” conducted by 3M for their 3M Window Film Prestige 70 product. 3M states in their experiment’s executive summary,
“While 3M believes that window films will have an overall benefit in reducing solar transmission, individual heat load and energy savings results will always depend on the unique circumstances of the application. 3M, therefore, does not warrant or promise any particular level of solar heat reduction or energy savings. 3M also does not recommend using the percentage improvement numbers reported in this study to estimate annual energy savings for the entire building. This should be completed with an energy simulation program, such as EFilm.”
My dear readers, why do you think 3M included this disclaimer? Yet, the fact is I don’t think it is fair to blame 3M for doing so at all.
While 3M’s product should clearly work as designed on its own, there are simply too many types of window glass available in the market that could result in a different outcome once the film is applied and depending on where it is applied.
The bottomline is that you might achieve the same 31% improvement in average heat flux through the window with Prestige 70 as per 3M’s 4-day experiment, or you might be less lucky and get less.
It will be impractical for 3M to publish heat flux performance outcomes for every known specification of glass in the market.
Also, for readers who have gone ahead to install solar films in your household, recall whether your installers bothered to help you do an energy simulation to estimate your annual energy savings before installation, as recommended earlier by 3M? Chances are, they did not. So we are left to blindly trust that they work as advertised, at our full expense.
A reason why I recommend installing Low-E glass windows right from the start, is because it will no doubt be a costly project to replace all the windows with Low-E glass once the building is occupied and in use.
And then, it is also worth noting that window glass can be quite complex in build, and may be made up of multiple layers, for eg. double glazed.
The effectiveness of applying a Low-E coating also depends on which layer of the glass the coating is applied to.
Generally, it may be difficult to retrofit and optimally apply the Low-E film once your window is already installed in your building.
This is because the Low-E coating is perhaps best applied during the glass manufacturing process, to achieve optimal heat blocking results and durability of the coating in the final product.
So my dear readers, know your window glass so you can demand for the best ones as much as possible!
If you’re interested to find out more about Low-E glass, you may like to refer to this informational write-up by build.com.au.
Demand external facade window shading
(adapted from Code On Envelope Thermal Performance For Buildings)
Refer to the picture below. Ever noticed those structural shading devices protruding horizontally outwards, above the external facade windows? Yes, you are looking at what are referred to as Horizontal Projection Shading Devices. Zoom in and notice how every horizontal projection casts a shadow over their respective set of windows below?
Photo by Danist Soh on Unsplash
It is important for us to appreciate that such a simple design and feature holds the key to making our residential buildings much more heat resilient.
The horizontal projections help to passively improve internal thermal comfort for occupants.
However, does your own residence boast such horizontal projections, or similar?
And if not, have you bothered to question why?
Again, I can cite residential developments that TOP in Singapore as recently as 2017 with insufficient horizontal projections over external facade windows despite them being subject to significant annual sun exposure.
So why again have our own building professionals seemingly forsaken us?
Is it not common industry expertise that horizontal projections are crucially important for all buildings in Singapore, given our already naturally hot climate, and to add the global warming effects of climate change to our growing concerns?
So my dear readers, let us arm ourselves with the knowledge of horizontal projection shading devices, so you can demand for them as much as possible!
Demand heat-reflective paint (cool paint) for building facade and pavement
(currently not covered in BCA Green Mark)
I directly quote HDB in their Joint Press Release with TC as follows:
“Residents in Tampines can potentially enjoy a cooler living environment under a pilot project by the Housing & Development Board (HDB) and Tampines Town Council (TC), which will see approximately 130 HDB blocks painted with cool paint. The pilot aims to reduce the ambient temperature of the site by up to 2 deg C, through the use of cool paint – a type of paint containing additives that reflect the heat of the sun to reduce surface heat absorption and emission. The large-scale pilot project is being rolled out under the HDB Green Towns Programme, a key initiative under the Singapore Green Plan which aims to build a greener Singapore in the face of climate change.”
So my dear readers, once the technology has been tested and proven to work well in Tampines, why not consider cool paint during your next repainting schedule? I also look forward to seeing it make the next revision to our BCA Green Mark Scheme!
Still other ways to save on energy
You may also want to refer to the following links as they get updated:
And you thought there was no end to this marathon…lol
If you have other BCA Green Mark (Household Edition) ideas to contribute, either drop me an email on our contact page or drop them in the comments below. Once verified, it might make it into the next revision!
Remember, the chief enemy is still CO2! So sharpen your swords and strike with precision! There’s not much time left!
Photo by Manny Becerra on Unsplash
SideQuest: Obtain an intimate understanding of what Greenwashing is. It’s quite a fuzzy topic at the moment and needs immediate support from the legal community for a legalese expansion exercise. Contribute here in the “Call For New Greenwashing Terms”. Cast your vote in a poll for new Greenwashing Terms!
And for all readers who have made it this far…
Thank you. It literally means the world 🙂
Watch this space.
Suggestions for Improvement
The sections beyond are for my own compilation of suggestions for improvement, in the hopes that they will find the attention of the relevant stakeholder(s). Peace and no obligations. Just putting it out there 🙂
Suggestion For Improvement 1: Consider to create Benchmark EUI for Residential Buildings
Currently even with the recently updated BCA Green Mark:2021, the Scheme does not specify a benchmark Energy Use Intensity (EUI) for Residential Buildings. The closest building match I could find is “Hotels” and their benchmark EUIs are as per the table below:
A quick calculation based on the above benchmark EUI values for Hotels will suggest that a HDB 2R flat of estimated 46 m2 floor area, can consume 690 kWh of electricity per month and still be considered good enough for GOLD standard. This is approx. 4X more, and grossly above the real national average consumption of 170.2 kWh for HDB 2R flats, based on EMA data. Therefore, I will conclude that the benchmark EUI for Hotels is perhaps not useful at all to benchmark operational carbon (energy consumption) of households in Singapore, despite their arguably close relationship in terms of the use of space.
Perhaps it might be good to consider providing benchmark EUI values for each type of Singapore dwelling moving forward, even if it’s not packaged together with the BCA Green Mark Scheme, so as not to cause problems for its international use. The benchmark EUI values for residential buildings can help to allow households to gauge if their energy consumption levels are in line with what is expected based on a test controlled environment fitted with state-of-the-art energy efficient appliances, and not simply compare to national average consumption levels, which neither suggests they are ideal, nor suggests that electricity consumption should not, or could not be further reduced.
Suggestion For Improvement 2: Consider to regulate use of Task Lighting Design Best Practices
BCA Green Mark Scheme includes a Lighting Power Budget to guide the lighting design for most space types, but there is no section dedicated to Task Lighting Design. NEA’s “Resource Efficiency Guide for New Home Owners” officially recognised the benefit of Task Lighting in Households but did not go far enough such that objective results could be engineered and reproduced in similar fashion as when utilising BCA Green Mark’s Lighting Power Budget.
IDs and Contractors often custom design and build purpose-specific furniture for households, including various built-to-order workstations. Typically, there is ample capacity within the workstation structure, to integrate and conceal optimal task lighting, without having to compete for prime real estate on the workstation. These task lights are also easily and cheaply replaceable, and on top of that there is an existing Producer Responsibility Scheme to recollect used lighting fixtures in Singapore. Also, such integrated task lighting would avoid having the user to separately procure a table lamp, standing lamp, or the like, off the shelf. Moreover, such off the shelf lamps typically utilise much more material in their construction and finish, and are bulkier and recycled less.
Task Lighting Design could be regulated to adhere to best practices and tested outcomes such that households are able to fully capitalise on potential electricity savings through prudent designs from the get-go. If we leave it to the average user to adopt task lighting on their own, one may find that the outcome may be much less ideal, both in terms of lighting performance outcomes, and electricity savings.
Suggestion For Improvement 3: Consider to mandate use of Low-E glass for external facade windows in Singapore
Singapore is mostly sunny, with rain (and that’s it). I’m guessing there’s also a good reason why our annual weather/climate overview, published on weather.gov.sg only features temperature and rainfall. We hardly have extreme seasons unlike other countries, and will probably never find a good reason to keep heat in our buildings. This makes a strong case for installing Low-E glass. The decision-making process for considering Low-E glass in Singapore is significantly less complicated than it would be for other countries. Not to mention that the benefits will be perpetually enjoyed all-year round once installed in households.
Suggestion For Improvement 4: Consider to mandate use of structural shading for external facade windows of buildings in Singapore
The reason is pretty similar to the reason for my earlier suggestion to consider mandating the use of Low-E glass in Singapore. Except that I am aware that passive building design may include a variety of methods such as the design for recessed windows, which may nullify the specific need for separate horizontal projection shading devices. Other shading designs include large externally mounted screens/meshes that provide thermal shade for the entire facade, on top of contributing to the aesthetics of the building. So in essence, my suggestion is more essentially to consider mandating all external facade windows to have some form of structural “shading”, so as to minimise incident sunlight on them.
Suggestion For Improvement 5: Consider to officially recognise and regulate installation of door and window seals as a passive means of saving electricity
I am not aware of any official endorsement or recognition for the use of door and window seals in any Singapore-based building code or Scheme (do correct me if I’m wrong). Yet, this could very well be one of the most simple and cost-effective ways to reduce air leak and help save electricity consumption by our household cooling systems. It may also be good to have a test controlled environment set up to test the effectiveness of this solution and publish the results publicly. Should it prove successful in the test environment, I hope that an official section dedicated to Door and Window Seals can be considered to be included in the next revision to the BCA Green Mark Scheme.
Suggestion For Improvement 6: Consider to mandate use of cool paint on building facades and pavement once technology has proven itself in the HDB/TC Pilot Project
I fully understand that a Pilot Project for cool paint is still ongoing. And I am hopeful that the results will turn out favourable. Should it prove successful at scale, I do hope to see cool paint covered in future revisions to all related passive building design standards, including BCA Green Mark, in a way that no dwelling type will be left out.
Suggestion For Improvement 7: Consider expansion of the Climate Friendly Households (CFH) Programme, introduce zero/low-interest financing options, and penalties for wayward professionals
Temperatures are rising in Singapore. Air-conditioning is marked as the biggest guzzler in the average Singaporean household (36%). The strain on our already limited Renewable Energy (RE) resources remains high. Perhaps we need to consider regulating the air-conditioning industry more tightly to conform to well-known best practices, in order to optimise electricity consumption as much as possible.
A full air-conditioning retrofit project is costly for a 4-room HDB household (~$6000, based on a setup of one system 3 multi-split, and two single split systems), the most common type of dwelling in Singapore. The upfront investment is difficult to justify on its own, even after considering potential annual savings, and especially when one considers that one’s existing setup is still fully functional. A combination of an expanded CFH programme, and availability of zero/low-interest financing options under green finance schemes for such projects will have a significant impact on low-carbon change management for households.
And then, one might ask if the energy transition needs of Singapore can afford existing households not being initiated on forced retrofit air-conditioning projects, especially those who are currently using still functional, but very low-efficiency models (sometimes 2x worse than their state-of-the-art variants). Immediately, freehold lease properties come to mind.
All existing households should not be excluded.
Also, consider setting penalties on wayward companies which owe a duty of care to provide sound advice to consumers during purchase/installation of air-conditioning systems. Solutions proposed should not overshoot best practice requirements as it can result in adding unnecessary but significant stress to our nation’s energy requirements.
Suggestion For Improvement 8: Consider to mandate all air-conditioner manufacturers to integrate user-friendly functionality to set programmable persistent (recurring) on/off timer settings from their bundled remote control.
A SUPER EASY way to save A LOT of electricity is to allow one to easily configure persistent settings for the air-conditioner to switch off 1-2 hours before one typically wakes up. Just by doing that, one saves up to 730 hours/yr on a single split unit air-conditioner system (~$250/yr on electricity costs, based on a 1.25kW single split outdoor unit, and electricity tariff rate of 27.22 cents/kWh).
And this is something one could set once, then forget about ever needing to change the settings, at least until one’s sleeping habits change. Yet, some major air-conditioner brands still do not provide such functionality by default.
Currently, one would need to set the on/off timer via the controller during operation of the air-conditioner. Once the set timer is triggered for that session and the air-conditioner auto switches on or off, the last on/off settings for the timer is cancelled (retired) and one has to start all over again during the next time the air-conditioner is in operation. And yes, that means one has to set the timer every single day!
A current workaround is to use third party universal IR remote hubs that can simulate the air-conditioner controller and remotely schedule persistent on/off timings. There are many currently available in the market but none can guarantee compatibility with one’s installed model of air-conditioner. There will be many who will not be able to justify the risk at the point of purchase. As such, this cannot be treated as a permanent solution to the problem.
This is such a simple way to achieve demand-mitigation on our use of electricity, but carries an immense potential for impact and at the same time, reduces the strain on our limited Renewable Energy (RE) resources.