Exposure on Elevator Ride is full of air-borne transmission

Top News

Otis Worldwide Corporation (NYSE: OTIS) released the results of a three-month academic study that investigates how elevator airflow affects potential exposure to the COVID-19 virus and a science-based approach for how to mitigate that exposure in elevators.

Findings show the significant amount of air exchange present in most elevators combined with simple mitigation strategies, including all riders properly wearing a surgical-style mask and the installation of a common type of air purification system, puts an elevator ride on the lower end of the exposure spectrum.

The study indicates strongly the provision of air purification system inside the lift car reduce the airborne transmission

MITIGATION STRATEGIES – VENTILATION CAN REDUCE RELATIVE EXPOSURE EVEN FURTHER

The study was led by Dr. Qingyan (Yan) Chen, the James G. Dwyer Professor of Mechanical Engineering at Purdue, who is widely recognized for his research into the spread of infectious disease through indoor air systems – and how to prevent it.

“Air exchange is important. the study findings concluded that the higher ventilation in an elevator, relative to the compared activities, results in lower exposure opportunity. If all passengers properly wear masks, the relative exposure risk drops 50%. Air purification, called NPBI, can reduce this by an additional 20-30%,”

Source: https://www.otis.com/zh/hk/news?cn=otis-releases-elevator-airflow-study-findings-covid-19-exposure-on-elevator-ride-is-low-risk-with-simple-mitigation

RISK OF CONTAMINATION IN LIFT CAR – PISTON MOVEMENT CREATES THE AIR DRAG

The study further investigate the position of the air inlets and outlets relationship. Alike to our another presentation 2021 and the study-2008 by University of Hong Kong, the position of inlet/outlet does significantly influences the flow circulation and droplet dispersion.
An air purifier does not eliminate airborne transmission. The droplet dispersion is reduced when a pair of an inlet and an outlet is implemented. The overall practical conclusion is that the placement and design of the air purifier and ventilation systems significantly affect the droplet dispersion and AVT. Thus, engineering designs of such systems must take into account the flow dynamics in the confined space the systems will be installed.

 

Source:https://aip.scitation.org/doi/10.1063/5.0038180

VENTILATION & AIR PURIFICATION SYSTEM SELECTION

(NCCO installation by Kingclorence)

The ventilation inside the Elevator is governed by legislation and code of practice from EMSD. It will be great if the position of inlet / outlet may be given due consideration in term of droplet dispersion and aerosol. Thus , in the absence of retrofit for outlet / inlet , the quick fix is to install the air-purification machine which can encourage the positive air flow.

There are different types of air purifiers in the market which can kill virus and improve air quality of the indoor environment. The size of your room is an important factor for choosing a suitable Air purifier. Bigger spaces will need larger air purifiers so make sure you choose an air purifier that can operate in a space that is 20-40% larger than the room for the best performance. GBE offers site inspection services for air quality control and recommends the air purifier for your best suit. Please contact us for more details.

Thank you

 

Does “Exempted Works” Matter you ? Court Case Referred

Unauthorised Building Works be the Deal Breaker 

In the court case Mariner International Hotels Ltd v Atlas Ltd (2007) 10 HKCFAR 1 , the parties involved were in legal fight about the Sale and Purchase agreement. One side was looking to exit the contract due to the steep down of the slump property market. The strategy they have adopted was to pinpoint some alleged unauthorised building works which might cause a toll to the “title”.  The court case was regarding a hotel valued more than HK$1 billion in 1996. The interesting thing in this case was the decision in Court of Appeal was revolved finally in the Court of Final Appeal. The definition in Section 41(3) of the Building Ordinance were subject to high scrutiny to its literal meaning and legal intention.

https://www.agoda.com/bay-bridge-lifestyle-retreat/hotel/hong-kong-hk.html?cid=1844104

The three structures involved in the court case (all on the roof of the hotel):

  1. Concrete plinths: a base for an air-conditioning chiller plant
  2. Gondola post: part of the system for cleaning the exterior walls and glass of the buildings
  3. An opening in the roof slab: for passage of a chilled water return pipe

Concrete plinths: https://www.bd.gov.hk/en/building-works/minor-works/minor-works-items/index_mwcs_items_c2b.html

Gondola post: https://sites.google.com/a/astec-technology.com.sg/astec-technology/product/BMU-System-Gondola-System/BMU-Davit-Arm-Gondola-System

An opening in the roof slab: https://www.roof.hk/kwun-tong-all

 

Section 41(3) of the Building Ordinance (version in 1996):

In 1996, Building works other than drainage works, ground investigation in the scheduled areas or site formation works not involving the structure of any building may be carried out in any building without application to or approval from the Building Authority.(Amended 44 of 1959 s. 21; 41 of 1982 s. 11; 52 of 1990 s. 8)

Provided that nothing in this subsection shall permit any building works to be carried out in contravention of any regulation.

The party putting forward the allegedly unauthorised building works argued that the structure on the roof of the hotel are not“in” the building and “involving the structure of the building”.

2004: Court of First Instance (decision later revolved by CFA) 

The judgement of Court of First Instance was issued in 2004, the judge thought that all three structures fall in the criteria listed in Section 41(3) of the Building Ordinance, therefore, they are not unauthorized building works.

  • Structures were “in” the building:

The judge thought that the three structures were “in” the building because they could be reached only by entering the hotel.  “In” is expressed in a broad sense, to denote a physical juxtaposition which may not necessarily include a complete enveloping. Examples “in” the building such as works which were within the parapet walls or the external envelope of the building were given by the judge. To support this view, the judge referred to the text of a bill to amend the Building Ordinance which proposed to change the section 41(3) to “works which are to be carried out inside an existing building”. The judge thought that this showed the government considering “in” did not mean “inside”.

  • Structures do not involve structure:

Second, the judge equating “involving the structure” with “structural”, which means, to affect or involve the structure, building works had to be a structural element. Hence, placing a heavy weight on the roof, or bolting it to the roof, did not mean it had become part of the structure, even though the weight had to be taken into account in loading calculations. Unfortunately , this “involving structural element” explanation was later rebutted by CFA.

2007: Court of Final Appeal

Nonetheless, the judgement of Court of Final Appeal reverse the decision made by the Court of First Instance.

  • Structures were not “in” the building:

Lord Bokhary PJ agreed that the interpretation of wordings in Section 41(3) should be narrowly in a manner consistent with the statutory scheme of which it formed part instead of a broad manner as mentioned by the judge in the Court of First Instance. It is because the purpose of the building legislation is to protect the public by subjecting structural acceptability to the scrutiny of the Building Authority, widening the exemption would reduce the scrutiny.

As regard “in the building”, Bokhary PJ’s view was that works on the roof of a building are not “in” it. There was, he observed, a purposive difference, relevant to safety, between building works protected from the elements by being in the building and those exposed to the elements.  Also, building works on the roof of a building are not ”in” it. Bokhary PJ then also added that he would not cut down the meaning of the word “in’ by recourse to the proposed amendment by which “inside” would be substituted for “in”, since the judge thought that the proposed amendment is to avoid doubt.

Another Court Case Concerning the Definition of “in” the building:

In Bright Dragon Properties Limited v Director of Lands, the judge express that “in” the building means within the parameters and under the ceiling cover of the building.

  • Structures not involve building structure:

Lord Bokhary PJ held the view that building works which served a structural function or were capable to affect the integrity of the structure are involving structure of the building.

To exempt from applying to or getting approval from the Building Authority before construction, the building works should be not involving the structure of the building and in the building. Both criteria should be achieved in order to exempt from approval. Hence, even if only one criterion is achieved, and the building work did not approved by Buildings Department, the building work will also be classified as Unauthorised Building Works (UBW).

2007: Amendment of Buildings Ordinance and Implementation of Minor Works Control System:

This court case attract attentions from different parties and speed up the amendment of Buildings Ordinance in 2007. To facilitate building owners and occupants in carrying out small-scale building works which do not falls into the exemption of Section 41(3), the Buildings Department imposed a Minor Works Control System. If building owners carry out building works that falls into the scope of Minor Works Control System but did not submit the required documents, the building works will be classified as Unauthorized Building Works (UBW).

  • Government proposed version

“Building works (other than drainage works, ground investigation in the scheduled areas, site formation works or minor works) in any building are exempt from sections 4, 9, 9AA, 14(1) and 21 if the works do not—

(a) alter the structural elements of the building; and

(b) bear any imposed load, wind load or dead load other than that due to their own weight.”

  • The wordings in proposed version was unclear commented by HKIS

Later on, HKIS submitted comments regarding the Buildings (Amendment) Bill 2007. They asked for clarification for the phase “bear any imposed load or dead load other that than due to their own weight”, because many very small scale building works also bear some imposed load, for example, the installation of hanging cabinet in kitchens or hanger rails in bathrooms.

Hanging Cabinet: https://www.realdealstubblefield.com/learning-to-install-kitchen-cabinets/

Hanger Rails: https://xiduoli.en.made-in-china.com/product/KOSEVDTdLGkX/China-Bathroom-Hotel-Wall-Mounted-Bath-Holder-Brass-Hanger-Rail-Towel-Rack.html

The Bill Committee Members agreed that certain exempted works are likely to bear imposed load and the proposed section 41(3)(b) could not clearly reflect the policy intent. The Administration was requested to improve the drafting of section 41(3).

  • The Administration modify the wordings

Then, the Administration clarified that furniture or fixtures such as kitchen cabinet or hanging rails within buildings are exempted in policy intent. The Administration admitted that the proposed wordings cannot clearly reflect the policy intent and planned to modify the wordings.

Today Current Version

“Building works (other than drainage works, ground investigation in the scheduled areas, site formation works or minor works) in any building are exempt from sections 4, 9, 9AA, 14(1) and 21 if the works do not involve the structure of the building.”

 

GBE welcomes comments from Professionals and enquiries from the Public

COVID-19 Outbreak From Fitness Centre and Restaurant

Top News

Call it an oversight or yet another loophole in social-distancing measures, but Hong Kong is again gripped by a serious Covid-19 outbreak. Centred on a gym in Sai Ying Pun, the cluster on Friday accounted for 47 cases that contributed to a dramatic surge in the city’s daily number of infections to 60.

Whether it heralds a fifth wave of the epidemic, as some experts are suggesting, is irrelevant; what matters is that for all our experience with the disease, a foolproof approach to containing its spread has still not been formulated.

The super-spreading event at Ursus Fitness seemingly resulted from instructors and customers not wearing masks. They were not required to; authorities had exempted people from wearing masks if doing vigorous exercise, even in indoor public places.

This is despite Covid-19 being spread by people exhaling and that being more pronounced when they are exercising. Belatedly, the government has reinstated the requirement of mask-wearing. All gym staff in the city have been ordered to have a coronavirus test by Sunday.

The oversight has been highly disruptive; in addition to the staff and customers who have tested positive and the gym’s closure for deep cleaning, 240 people who visited recently have had to be quarantined. Some were believed to be bankers, lawyers and educators, and offices and colleagues have been affected.

Source: https://www.scmp.com/comment/opinion/article/3125297/hong-kong-gym-outbreak-again-underlines-need-exercise-caution

VENTILATION IS KEY TO FIGHT COVID-19 TRANSMISSION

Source: https://www.scmp.com/news/hong-kong/health-environment/article/3123251/hong-kong-expecting-around-20-new-coronavirus

According to The Wall Street Journal, after urging steps like handwashing, masking and social distancing, researchers say proper ventilation indoors should join the list of necessary measures. Health scientists and mechanical engineers have started issuing recommendations to schools and businesses that wish to reopen for how often indoor air needs to be replaced, as well as guidelines for the fans, filters and other equipment needed to meet the goals.

Source: https://www.wsj.com/articles/key-to-preventing-covid-19-indoors-ventilation-11598953607

The above videos show how airflow can be visualized without a mask.

Ventilation System to Become an Integral Part Property Grading

Office interior with white columns and panoramic windows in modern loft. Many green plants in pots in workroom with laptops on tables with chairs and cups at daylight, flat lay, nobody, free space

The latest outbreak served as a dire warning for Hong Kong. Covid-19 shined a harsh light on how ventilation can impact business continuity and endanger capex investment. Ventilation provision has become a strict prerequisite for businesses that comes before any initial capital investment and expenditures in order to ensure business continuity.

Which operation demands ventilation

Obviously, all operations require ventilation, but what the standard of ventilation is and how to achieve it? The laws involved are from Schedule 2 of Public Health and Municipal Services Ordinance (Cap.132) and the Buildings Ordinance (Cap. 123). The former legislation is to control “SCHEDULED PREMISES” where crowded space is anticipated while the latter legislation deals with office space.

Second Schedule
[ss. 2, 93 & 102]
Scheduled Premises
(Format changes—E.R. 4 of 2019)


Class of premises
No. of cubic metres per hour for each person who may be accommodated in the premises
Cinemas
13
Dancing establishments
17
Factory canteens
17
Funeral parlours
17
Restaurants
17
Theatres
13

Air Supply Vs. Air Change

The current standard enforced in ventilation in office buildings is the volume of “air supply”, not numbers of air change. There is a huge difference between these two concepts. Air change, which is repeatedly mentioned by the microbiologist, is NOT mentioned by the law.

Massive ducting is needed for air change results no incentive for better system

To achieve the required air change standard, the ducting quantity and sizing is likely almost double than that of normal air supply provision, making it almost impossible for many offices and premises to achieve. Developers are used to providing the minimum standard as required by the law, and not catering to users nor designed for preventing viral outbreak.

Proper Air Treatment System is the Silver Shield

Along with WFH, Social Distancing is an implied feature of our society today. With the slow adoption of the vaccine due to issues stemming from logistics and mistrust, we can expect that limitations on physical gathering may still be in place for the better of 2021. This means that businesses and schools may experience intermittent closures, and productivity technologies such as Zoom will become a more permanent part of work.

Creating indoor air circulation system with Air Treatment

Source: https://www.wsj.com/articles/key-to-preventing-covid-19-indoors-ventilation-11598953607

While air change with external air involves substantial ducting engineering, many operators may consider building the internal circulation system to significantly improve the air quality. There are different types of air purifiers in the market which can kill virus and improve air quality of the indoor environment. The size of your room is an important factor for choosing a suitable Air purifier. Bigger spaces will need larger air purifiers so make sure you choose an air purifier that can operate in a space that is 20-40% larger than the room for the best performance. GBE offers site inspection services for air quality control and recommends the air purifier for your best suit. Please contact us for more details.

See How Strategic Air Purifier Placement Reduces COVID Virus Spread Within Music Classrooms

Air Purification System Selection

 

There are different types of air purifiers in the market which can kill virus and improve air quality of the indoor environment. The size of your room is an important factor for choosing a suitable Air purifier. Bigger spaces will need larger air purifiers so make sure you choose an air purifier that can operate in a space that is 20-40% larger than the room for the best performance. GBE offers site inspection services for air quality control and recommends the air purifier for your best suit. Please contact us for more details.

 

Turning Non-domestic space to Domestic usage for Public Rental Housing

To boost the housing supply is the urgent needs in today HK. Although many resources such as transitional housing and new town development are allocated , GBE has been working on two interesting cases which are to convert the “non-domestic space” to domestic usage. We love to sharing our experience to all reader.

Technical Hurdle for conversion 

There are many technical consideration to the conversion. To list some, the issues cover the “GFA” , “site coverage”, natural lighting and ventilation, open space, Fire safety are all in the radar . On top of this , some tricky issues such as concrete cover ; width of re-entry for open space; barrier free access ; provision of gas aperture , Kitchen, sanitary fitment and the clear headroom for the domestic space are all counting on.

Overcome the hurdle

It is technically complex to resolve all the issues in one scheme. We have to prioritise the amount of effort to resolve each problem. Honestly , some of the technical hurdle may be too costly to resolve or even not possible to overcome

  • GFA and site coverage is the most tricky

Among all the hurdles, the GFA and site coverage are the most pertinent and profound factor. We have had a blog talking about the GFA conversion. Honestly , in the case of conversion, we usually have to rebuild the entire GFA calculation and site coverage from scarp. It boils down to the classification of site, open space and roof cover area. It is highly tedious but technical process.

  • Lighting and ventilation / fire safety 

Many peers usually have the impression that these are resolvable and always undermine the inherent difficulties. Let us share you one point, the importance of the RHS and prescribed windows are always in the play. Since the RHS is dictated much by site surrounding and site boundary, it eventually restricts the design of light/ventilation very much

The same hurdles happens to the fire safety. Some of the professional may overlook the essence of the concrete cover and believe the fire proofing materials be helpful. Unfortunately , the clear headroom of the space is always very limited and the resulted headroom after the new fire protection layer added may lead to inadequacy, it sounds ridiculous but it did happen.

  • Sanitary Fitment and Kitchen 

These are not usually posing difficult , but the problem raised from the gas aperture for the bathroom, the RHS for kitchen and the drainage provision for the sanitary fitment. The gas aperture’s design demands a lot of the space consideration while the kitchen needs the RHS. When all these factors come together, the layout of the apartment becomes quite challenging

Looking forward to the future

While a lot of resources have been allocated to MiC , Transitional housing and New town development , we can see there are some abandoned or under-utilised space in urban area , which can be converted into the habitation purpose. We have attempted successfully such conversion in some old districts in Hong Kong. We hope we can bring more similar cases for sharing in future

 

Make Use of Verandah in High Rise Buildings for Fire Safety Aspect

The impact of Fire Safety Code in Hong Kong

The fire safety code has experienced a few rounds of reform. The most influential reform we opined was the code published in 1996 and also the code in 2011. While there are many honorable peers have shared the view to both code applicable in Hong Kong, GBE found one interesting HK-unique escape staircase arrangement which have been prevailing in 2 decades ago. This the verandah space intercepting between the apartment units and the requirement staircase (usually scissor-type)

 

Verandah Space being merged 

This verandah space was a space designed in half-open to the external air. The space is connecting between the staircase and the apartment unit through the fire-rated doors. Driven by congested space in Hong Kong, some verandah, in this case, has been enclosed by the window and merged to the apartment units. This was deemed to be against the fire safety code or approved plan.

 

GBP for showing the Typical location of the verandah in a domestic unit

The Provision of HK CAP 502

In 2007, the HONG KONG CAP 572 Fire Safety (Buildings) Ordinance has been put into enforcement. The “Purpose Of Ordinance” is cited in clause 2 of Cap 572 and We copied here as follows.

This ordinance is aimed to provide protection from the risk of fire of occupants, users, and visitors to certain kinds of composite buildings and domestic buildings.

The law further explains the requirements including fire service installation and equipment and fire safety construction for different kinds of buildings in its Schedule 1 , 2, and 3 correspondingly. The governing requirements stated clearly is to apply the Code 1996 as the “standard” to satisfy the intention of this Ordinance. Thus, the said “Verandah” enclosure or modification is likely in this radar.

 

What did Code in 1996 talk about the “Verandah”

In our view, there was no direct elaboration to the “veranda” being designed for the intercepting lobby between the required staircase and the unit. From the MOE code 1996 and FRC 1996, there was a few relevant paragraphs which came up eventually the “veranda” application as a protected lobby. Since the author was not the Code writer nor in an authoritative position to comment, this blog of write-up serves to trigger some interesting discussion.

 

The provision of the “Protection” lobby was written in clause 13.5 in MOE 1996 and the design of “Protection lobby” was explained in 11.3 FRC 1996. Nevertheless, the enclosing wall of the Protected lobby was further explained in clause 11.7. Honestly, it was a complex integration of different clauses at different code and could easily lead to various explanation outcomes. This undesirable situation such complex set of codes has been improved in lately 2011 code.

The interpretations of Protected Lobby stated in MOE 1996 Code

The design of “Required staircase and protected lobby” was explained in Clause 11.3 at FRC 1996 Code

The Clause 13.5 in MOE 1996 Code

Indeed, the old 1996 code has remarked very clearly in clause 13.5 MOE 1996 code that “such lobby shall be designed as a common area and an integral part of the staircase so that it could not be readily incorporated as part of any adjacent unit(s) of accommodation” The 1996 code did aware the issue of merging the protection lobby to the private unit. Nevertheless, the complex nature of the set of codes 1996 which led to different explanations may undermine the intention in clause 13.5.

Plan for demonstrating the Verandah between the required staircase and the apartment

Above is another example where the “Veranda” was inserted between the escape staircase and the apartment. Interestingly, the kitchen doors also opened to the verandah. It was believed that this layout configuration is hardly survivable in today’s Code.

“Common Staircase” shared by adjoining lot in Hong Kong

The leftover structure coming from rapid Urban redevelopment in Hong Kong

In the urban development , the land was delineated by “Block” and was subsequently craved or partitioned in a different section and eventually further craved into different sub-section. It resulted a lot of common boundary to each piece of lands adjoining to each other.

 

The common boundary bought in the typical implication of “party wall” and “common staircase”. There was a blog written by GBE about “party wall”. The reader is welcome to comment. “Common staircase” is what this article goes deep.

 

The main staircase of the building became as “common” because it was commonly shared between two pieces of land. The common staircase was jointly owned for the enjoyment of the entire building. Since it was common to two adjoining pieces of land, it naturally positioned at the boundary line. It was not a must but naturally came up in the middle between two lots.

Redevelopment and remaining common staircase

With the re-development took place in one piece of land, the adjoining land where the original main building sitting on was necessitated to maintain the common staircase for access. This came up the situation alike to the “Party wall” where the common staircase needs to be retained and still occupy land and space on the land going to be redeveloped.

 

The first and immediate concern is obviously the common staircase is an enclosed space and fall into the definition of GFA. Nevertheless, this common staircase is nothing helpful and undesirable to new development. To cope with this, the above-extracted part plan has illustrated the example of how the PNAP ADM -2 resolves the GFA problem. In short , the entire footprint of the common staircase be deductible from the GFA calculation. According to PNAP ADM-2 from the Buildings Department, the existing common staircase for an old building can be excluded from site coverage and plot ratio calculation.

 

Case Study in two adjoining Urban buildings

Building “A” was redeveloped in 1992. The landlord was obligated to leave the common staircase un-touched and exempted its footprint from accountable GFA. Building “B” was subsequently redeveloped in 2008, but the redevelopment of Building B has demolished partly the “common staircase” sitting on the respective piece of land.

Ground Floor Plan of Building A (showing the Location of Common staircase with Building B)

 

 

GFA Calculation of Building A

 

Ground Floor Plan of Building B (showing the Location of Common staircase with Building A)

 

 

Site Area Calculation in Building B

Another example showing the common staircase issue

Building “C” was redeveloped in 2004, while Building D was redeveloped in 1994. Building “C” and Building “D” retained the common staircase after both redevelopments.

Ground Floor Plan of “Building C”

Ground Floor Plan of “Building D”

Funny interesting maintenance issue

The interesting things come up is that building A which developed earlier than Building B was containing the old “common staircase” . This old left-over common staircase in Building “A” was not GFA counted by the time of redevelopment. The owner of Building A is caught in dilemma. The site where building A sitting on has fully exploited its GFA potential by the time of its redevelopment in 1992. It is now found no surplus GFA be able to assign to this leftover physical ” common staircase” space in the hope to light up again the space utilisation, particularly valuable in highly urbanised city area. The landlord of building A is naturally no incentive to maintain nor convert this common staircase to other proper usage. The only value is the external wall of the left-over common staircase which was being poised for signage in Building “A” (as shown on the photo below. Obviously, the author is wondering the maintenance liability to the grandfather jointly owned structure , i.e Common staircase

 

Misery of Non-accountable GFA in Existing Building. The road from plain drawings to value-added

GFA is the core asset in real estate

GFA – Gross Floor Area is considered as the core valuable asset in real estate. One of the significant governing regulation to GFA stated in Buildings Ordinance is Building (Planning )Reg 23. The Reg 23 (3)(b) have listed in literal form the areas which can be subject to non-accountable GFA whereas the Reg 23(3)(a) has included all areas within the external of buildings as GFA countable.

The Ordinance allows some accountant GFA in 23(3)(a) becomes considered as non-accountable GFA through the power vested to Buildings Authority by section 42 of Buildings Ordinance and explained by the ADV – 02 (PNAP 30 in former version). Some GFA calculation cases are further complicated by the injection of sustainable development requirements stated in APP 151.

Existing Building GFA vs Regulation 23(a) 

In existing Building which was built in decade ago plus , the control to the non-accountable GFA was relied by Reg 23(3)(b) which generally covered the essential plants / duct / carpark etc. When the landlord wants to review/revamp the existing GFA hoping for unlocking the hidden potential, the latest requirements in 23(3)(a) mentioned before will kick in to the backdrop.

Some areas within the building which had been exempted from accountant GFA in the past may have to re-examine under Reg 23(3)(a) and is assessed in the ADV -02. The interesting but painful point is that some typically exempted in the past may now become accountable unless the modification is granted by BA. In some case, the modification is not straight-forward but under complex assessment such as BEAM requirement in APP 151. Obviously, the latest GFA requirements has blocked the unlock of some potential GFA.

Example showing the effect impact from tightening of GFA assessment

Assuming there is plant room , this plant room is assumed be acceptable by Reg 23(b). The implication of GFA will be manifest because the protected lobby going with the plant room will be exempted. To the contrary, If the said “plant room” is NOT in Reg 23(b), the GFA exemption will be at the stakes. The wall and associated protected lobby solely serving for plant rooms will be subject to the “non-mandatory features”. The area of wall and associated protected lobby will be barred by the overall cap of 10% in paragraph 4 APP 151 for non-mandatory features) . The capping 10% will effect some GFA from non accountable back to accountable.

Case by Case assessment 

Valuable assets in the urban areas are all GFA driven for the best maximization of property value. This is the key driving incentive to closely review and revamp from time to time to unlock the potential hidden GFA in the active asset management.

(Reader is advised to look also other strategies which have been shared in our other blog” of this website)

 

 

 

 

EV Parking vs Additional FSI

Demand for EV Charger facilities in existing (old) building carpark is definitely rising in the town. Many would focus on reliability of new power consumption, enhancement of infrastructure and how best to house those new facilities. In GBE, fire safety with respect to the additional fire load of EV charger facilities is also our key consideration on design and planning of project. Incorporation of smoke detection system, fire extinguisher, Direct Link connection and Fireman’s emergency switch, etc. are encouraged for the relevant project. Enhancement of client’s assets and upholding of high level of safety are one of our major deliverable to our clients.

Part 2 : Coating materials for Aluminium cladding – Misery of “Self-cleaning”

Following with our part 1 discussion, we now share another hot topic about coating applied on the aluminium. “Self-cleaning” is indeed a merchants’ name . The behind sciences are varying from among different manufacturer. We have conducted some comparison among different materials being applied to the cladding surface.

Theory of “Self-cleaning”

Self-cleaning : Hydrophilic approach 

In short, there are a few theories behind the “self-cleaning” . One typical approach is to create the surface which reduce the water surface tension. When the water droplet lands on the surface, the water droplet has formed an wetting angle to the surface of cladding. The stronger the water tension, the more acute the wetting angle is. The below diagram explains the wetting angle and how it carries the dirt / stain / attachment on the surface. Different manufacturer has formulated different chemical materials to reduce the water tension and flatten the wetting angle. The water is to carry and flush away the dirt. The most typical chemical approach is to create the coating surface which offer better hydrophilic (hydrophilic is origin from latin word, the word philic means love).

 

 

Self-cleaning : Photo-catalytic Oxidation 

Another theory is by “Photo-catalytic Oxidation” . We are not Chemist and cannot cite the theory . Nevertheless, we found one extract from “Chemosphere 193( 2018-198-206)” ,  there explains the “photo-catalytic oxidation” with the below graphic. In short, it is the oxidation process to the VOCs by UV and Photon. This is again alleged by many peers as ” self – cleaning” , but obviously the theory is very different from “hydrophilic approach”

Self-cleaning : Hydrophilic approach

To the contrary of “Hydrophilic” , some manufacturer applied the opposite ; hydrophobic approach. The theory behind is to keep the strong water tension of the droplet and let the droplet to “PICK” the dirt away. From our very preliminary scanning , this technique was more relying on the water – repellent nature ,

Product in the market : – 

We have encountered different approaches in the market. All suggest their “self-cleaning” properties. We try to cite some examples to illustrate different theory behind . We are not in the position to comment each performance and indeed it is difficult to do comparison. We hope this articles can offer some ideas for future research

Kansai Paint : 

One of the product is made by Kasiai, we were given the understanding that the materials is silicon-based modified resin materials with their own additive untold to the public. This is to create the “Hydrophilic” by flush and deliver the dirt.

 

 

Hydrotech from TOTO

Hydrotect is the tradename by TOTO. We extract their self-allegation from their official website. In short, they claimed their coating technique is photocatalytic which is to OXIDE the VOCs in the air. Their website further suggests this “Hydrotect” can offer the hydrophilic surface to flush the dirt

XX Sheet film paper 

A manufacturer , named to be untold here, claimed that there film sheeting offer the self-cleaning. We cannot identify their theory online. Nevertheless, we did a quick water spray test on the surface. We noticed that the water droplet kept intact on the surface and did not appear wetting pattern which is for flushing the surface.  From the picture below, the water – droplet keeps visually keeps the sharp and the droplet drip pattern is in the form of line.

 

 

Condensation Issue in Building – Part 1

Unwanted condensation can cause the building damage and also affect human health. In Hong Kong, condensation is a common problem which almost every single owner has to deal with. Temperature difference and high humidity are the main causes lead to condensation occurs.

Condensation is created when warm moist air begins to cool down and the moisture is released. This moisture then settles on cold surfaces making them damp. This can happen quickly when warm moisture in the air connects with cold air or surfaces, such as having a shower and the steam from the shower hits the cold window or mirror making it wet to touch, this is condensation.

Source: https://www.falkirk.gov.uk/services/homes-property/council-housing/repairs-maintenance/docs/condensation/Condensation%20in%20your%20home.pdf?v=201910291603#:~:text=Condensation%20is%20created%20when%20warm,and%20the%20moisture%20is%20released.&text=This%20can%20happen%20quickly%20when,to%20touch%2C%20this%20is%20condensation.

Information from Hong Kong Observatory

March and April are milder although there are occasional spells of high humidity. Fog and drizzle can be particularly troublesome on high ground which is exposed to the southeast, and air traffic and ferry services are occasionally disrupted because of reduced visibility. May to August are hot and humid with occasional showers and thunderstorms, particularly during the mornings. Afternoon temperatures often exceed 31 Degree C whereas at night, temperatures generally remain around 26 Degree C with high humidity. There is usually a fine dry spell in July which may possibly last for one to two weeks, or for even longer in some years.

Source: https://www.hko.gov.hk/en/cis/climahk.htm

 

On average, May is the most humid.

On average, December is the least humid month.

The average annual percentage of humidity is: 77.0%

Source: https://weather-and-climate.com/average-monthly-Humidity-perc,Hong-Kong,Hong-Kong

Due to such high temperature and high humidity environment in Hong Kong, condensation will be easily occurs if lack of consideration in daily operation and usage of room. GBE has deal with many condensation cases caused by lack of communication in design stage and also in wrong material selection. With an detailed study and planning before design stage which can help in material selection and insulation. Also, the heat source from outside the unit or building will be needed to consider through out the design process.

Negative pressure in building which may cause a big effect of condensation as the hot air from outside collide with the cold air within the building. Many people deal with condensation problem with balancing the temperature and humidity difference between indoor air with outdoor air by ventilation. However, such measure is not practical when outside air is in high humidity which the ventilation system is not sufficient for get away the moisture within the area as the high humidity air will get through the window to indoor by negative pressure.

Source: https://basc.pnnl.gov/sites/default/files/images/HVAC515_whlbldgvent4_DS_1-10-13.jpg

The above image show that the exhaust-only ventilation only system may cause negative pressure which can easily made the outdoor air to the building or unit. In below example, a cold storage with 24 hours A/C control store room which was found with condensation problem with hot air getting through from outdoor air by negative pressure. The owner has installed a few dehumidifiers which were not sufficient to get rid of the moisture as the hot air from outdoor is non-stoppable. In such case, the high cost in electricity usage and also high maintenance cost may affect the owner in daily operation. GBE has studied and apply the insulation to stop the hot air to get in from the electrical cable duct and also can save the cost for running the dehumidifiers and prevent the rusting effect at the electrical cable duct.