time flies, just noticed 10 years as Director of BEAM Society Limited 🤣
The results from the Decarbonising Hong Kong public consultation were published by the Council for Sustainable Development in November 2020, one of the recommendations was energy saving building design.
One of our completed projects was featured in a HKGBC video, the HKUST Indoor Sports Center, Sai Kung, started years ago, but already incorporated energy saving building design.
It was a team effort, the whole team, the client, the engineers, the architect, and the contractor clicked, and delivered a project that scored 80% independently assessed used BEAM PLUS NB rating tool, earn final gold rating. It was challenging because BEAM PLUS NB is designed for a new build, not an extension over an existing building. The result I hope demonstrates and inspires future possibilities.
ABOVE: HKUST Indoor Sports Center
HKUST Indoor Sports Center achieved BEAM PLUS New Buildings Final Gold Certificate with an overall score of 80 points!
John Herbert was the project BEAM Professional, providing BEAM consulting, sustainable building design consultant, lighting consulting, and environmental consultant for the HKUST Indoor Sports Center, Sai Kung, Hong Kong.
by John Herbert (@johnherbert)
The No. 1 recommendation from the Decarbonisation Public consultation, Hong Kong should be Nett Zero by 2050 (published in Hong Kong Council for Sustainable development). Here is the link to the report https://bit.ly/38D6tvL
Since Hong Kong buildings account for around 90% of electricity consumption and therefore more than 60% of the Greenhouse Gas inventory, it must be obvious that buildings will be the targetted to dramatically lower emissions, that means improving energy efficiency.
This target, its still only a pledge, is broadly aligned with the targets in other countries in the region.
It is easy to promote a slogan without actually understanding the practical underlying details, the devil is in the details.
How can Hong Kong meet 2050 target?
by John Herbert (@johnherbert)
For building owners building air leakage costs extra money, whether it is through the additional energy use or poor indoor environmental quality. The latter, infiltration of polluted outdoor air and Radon are both a serious health concern impacting occupants.
Attempting rectification after occupation/renovation is always more difficult and time consuming, so the execution of the construction work is vital, we know it has a major impact on the airtightness of buildings.
Air leakage can be tested and verified during construction, using a 2 stage process using blower door test, supported with thermography (Infrared) and fog testing, to ensure unwanted air leakage is minimised.
In 2004 HK BEAM created 4/04 green building rating tool for new buildings, that introduced air leakage testing, and later in 2012 BEAM PLUS Interiors rating tool introduced air leakage testing for shops and offices, but regulation has not followed. Europe now has strict regulations requiring new buildings to undergo air leakage testing, to meet the country standard.
Therefore to help reduce building energy use and wasting energy, air leakage standards and testing are needed here in Asia.
Air Leakage Frequently Asked Questions (FAQ)
What is Building Air Leakage?
A building envelope with openings, sometimes due to poor construction, allows polluted outdoor air into the building.
What are the consequences of air leakage in buildings?
In Asia, air infiltration has several consequences:
- allowing hot humid air to enter an air conditioned building, causes condensation on interior surfaces, providing the right environment for growth of mould inside buildings;
- poor indoor air quality impacts the health of occupants;
- increased energy use;
How to Identify Building Air Leakage?
Air leakage can be detected using blow door test, thermography, fog testing to identify the location of the air leakages, but in most cases these do not quantify the amount of leakage corresponding to each leakage.
What is the Key Issue for Buildings with Curtain Walls
According to the ASTM standard for curtain wall construction, curtain wall have permitted air leakage rate that qualifies for the ASTM standard. ( xxx litres/sec at 300pa). that means buildings with curtains walls have air leakage.
Resources (suggest a resource?)
HK BEAM 4/04 version (PDF page 1-20)
- CAN/CGSB 149.15 – Determination of the Overall Envelope Airtightness of Buildings by the Fan Pressurization Method Using the Building’s Air Handling Systems
- The United States Army Corps of Engineers Air Leakage Test Protocol for Building Envelopes
- ISO 9972:2006 – Thermal performance of buildings — Determination of air permeability of buildings — Fan pressurization method
- ASTM E779 – Standard Test Method for Determining Air Leakage Rate by Fan Pressurization
- ASTM E1827 – Standard Test Methods for Determining Airtightness of Buildings Using an Orifice Blower Door
- EN 16798-3: 2017: “Energy performance of buildings – Ventilation for buildings – Part 3
tags: air leakage, infiltration, exfiltration, permeance, building envelopes, airtightness
By John Herbert (@johnherbert)
What is the reality in construction?
So, the structural drawings and calculations are complete, the architects drawings are complete, the scheme has been through BD approval process, the MEP engineering drawings are complete, the QS measured quantities and prepared the bill, the contract documents are done, and scheme has been signed off by client.
So now is the perfect time to assess the embodied energy? No, assessing the embodied energy based on completed contract documents is a purely an academic exercise, it’s too late, far too late to influence key decisions that could impact the embodied energy.
Think about it, tools that promoting assessment based on the finished design drawings steals any opportunity to influence choice of materials and therefore options for lowering embodied energy.
learn more about embodied energy and embodied carbon: http://www.kelcroft.com.hk/carbon-embodied-energy.htm
by John Herbert (@johnherbert)
Have to love academic research, boldly presenting and encouraging a new paradigm shift, in this case with the existing building stock being considered to be temporary raw material storage (you might remember the carpet example a few years ago).
But wait, when the ugly aftereffects, and so called unintended consequences do occur, everyone claims that was unforeseeable, really?
To reduce the rat population a bounty for every tail was offered, after paying the bounty and the population had not decreased. Finally it was discovered that rat farming in the countryside were breeding rats to collect the bounty. When stopped paying the bounty, the rat farmers have no use for their rats and released them.
In the real world, where commercial considerations apply, supply and demand matters. Firms set up to use the existing building stock to satisfy their production quota, creates an unequal pressure, the firm needing materials to keep their factory open, perhaps they might urge or incentive soonest demolition to use those “stored” materials.
Equally, the thermal insulation made from blue jeans (denim-insulation) is a great idea, but it will create and increase the market for old products, to keep their factory busy the owner might offer incentives for that materials, and overall increasing the usage of cotton.
In a complex world the best, logical solution may not be the only solution, and other possible consequences, although unintended, need to be considered.
One point that does bear repetition, only products that can be recycled 100% need be considered, if a new exotic product is created that cant be recycled, that is merely delaying its trip to the landfill.
Creating a vertical green wall is appealing “feature” although the reality is a lot different. It is a garden, and needs to be tended, in Hong Kong that requires a safe working platform typically a diesel powered aerial platform, this quick video shows the reality.
My quiet coffee break was interrupted by the noise AND pollution from this aerial platform preparing to tend the vertical greening.
If you live in an urban environment, the storage bank for constructing tomorrow’s buildings is all around you. Yes, those buildings will be deconstructed, becoming the raw material for tomorrow’s buildings. And if you are lucky you might find a building constructed from steel, which can be infinitely recycled.
Therefore, designers must consider how the building will be demolished and reused before its open.
The above drawing is from a new air conditioning building (designed 2020), an interior vapour barrier is stupid!
Why? The external vapour pressure is significantly higher (approx. 1kpa higher) than the interior vapour pressure in the air conditioning space, causing moisture flows toward and into the room.
However, the internal vapour barrier stops the flow, and traps moisture saturating the thermal insulation with water and destroying its thermal properties, and increasing the building energy consumption.
HKGBC recent asked for ideas to promote nett zero and lower energy consumption, the first step I suggest must be stopping architects doing stupid things!
To understand valuable design we also have to identify and flag cases of bad design. We find from the recent heath checks conducted at the Hong Kong International Airport that health professionals working on the frontline have inadequate facilities, was this foreseeable certainly, every border has provision for handling health checking.
The RTHK report [link] states
She said there were other problems concerning protective clothing, for example, no designated locations for workers to take off their gear.
In this context, their gear means their PPE. So the frontline nurses and doctors facing thousands of passengers, potentially carrying the infectious diseases including COVID19, don’t have adequate changing facilities risking themselves, and other employees at the airport.
After the shift, the PPE including a n95 mask for sale that I found, a gown, an apron, glove, face shield, etc. are considered contaminated, therefore, an appropriate space clearly identified, should be provided for healthcare workers to doff (remove) and don their PPE, but it seems the border control design did not provide such space, even a temporary space, and a frontline doctor tested positive for COVID19.
Design means considering reasonably foreseeable usage and planning according, health checks at borders are routine and commonplace for many years. If you are old enough to remember some countries made visitors present health records, but in this case, the designers ignored or overlookedthe healthcare workers.
In engineering terms, located transformers and switchgear underground is a risk, in the event of a blocked sewer pipe, flooding, or water leakage the building power supply or back up generator could be compromised. Of course, architects say oh that will never happen, until it does. In a recent Hong Kong incident, water leaking on the upper floor of the building flooded the corridor and the electrical meter room, water travelled down the building using the 2500 amp TPN busbar as the conduit shorting each floor, and continued to the LV switchroom in the basement, causing a disastrous short circuit, shutting off power to the entire building.
The takeaway, engaging and listening to people outside your field, outside your silo, gather views and ideas, consider future events and scenarios, while the building plans are still on the drawing board.