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Affordable Low and High-Rise Honeycomb Housing - 5 new articles
Your Building's Invisible Fire Shield: Understanding Compartmentation
Ever wondered how modern buildings are designed to keep you safe in a
fire? Beyond smoke alarms and sprinklers, there's a fundamental safety
concept at play that you might not even realize exists: fire compartmentation. Think of it as your building's invisible fire shield, des igned to
contain a blaze and buy you precious time to escape.
What is Fire Compartmentation?
At its core, fire compartmentation is about dividing a building into smaller, fire-resistant zones or "boxes". Imagine your building isn't just one big open space, but rather a
collection of sealed-off areas. If a fire starts in one "box," the goal is
to keep it trapped there, preventing it from spreading to other parts of
the building, especially the escape routes.
This isn't just about protecting the building itself; it's primarily
about saving lives. By limiting the spread of fire and smoke, compartmentation gives
occupants more time to safely evacuate and creates safer conditions for
firefighters to do their critical work. It also helps protect property and business operations by localizing
potential damage.
How Does This "Invisible Shield" Work?
The magic of compartmentation lies in special building elements designed
with "fire resistance periods" (FRP). This means they can withstand fire for a specific amount of time,
giving them "superpowers" against heat and flames.
Key elements of this fire shield include:
• Compartment Walls and Floors: These are the primary barriers, literally walls and floors built to
resist fire. They are constructed with materials and designs that prevent flames,
hot gases, and even heat from passing through for a defined period. The required fire resistance varies depending on the building's purpose
(e.g., residential, office, hospital) and its height.
• Fire Doors: An opening in a compartment wall is a weak point, so fire doors are
essential. These are not just any doors; they're specially designed to resist fire
and must have automatic self-closing devices to ensure they are always shut when not in use.
• Protected Shafts: Think of staircases, lifts, and utility ducts as vertical highways
within a building. If not properly protected, they can act like chimneys,
rapidly spreading fire and smoke between floors. Therefore, these "shafts" must be enclosed within fire-resisting construction themselves, essentially creating protected routes that fire cannot
easily breach.
• Fire-Stopping and Cavity Barriers: Even tiny gaps or hidden spaces within walls, floors, or around pipes
and ducts can allow fire and smoke to bypass compartmentation. Fire-stopping is the act of sealing these imperfections with fire-resistant
materials, while cavity barriers subdivide larger hidden spaces (like false ceilings or roof spaces)
to prevent unseen fire spread within them.
Where is Compartmentation Most Important?
Compartmentation isn't a one-size-fits-all solution; its application is
tailored to the specific risks of different buildings and areas:
• Larger or Taller Buildings: Buildings exceeding certain heights (e.g., over 9 meters or 30 meters)
are required to have compartment floors at specific levels, or even on
every floor, to prevent rapid vertical fire spread.
• High-Risk Areas: Places like boiler rooms, transformer rooms, and areas storing
hazardous materials must be separated from other parts of the building by
fire-resisting construction due to their higher fire risk.
• Basements: These are particularly vulnerable due to their below-ground location.
Specific requirements apply to basement floors, especially those exceeding
100 square meters, mandating them as separate compartments. They also require specialized smoke venting systems.
• Residential Units: Flats and maisonettes within a larger building must be separated from
other parts of the same building by compartment walls or floors to protect
residents.
• Mixed-Use Buildings: If different parts of a building serve different purposes (e.g., a shop
below offices), compartmentation is crucial to isolate the varying fire
risks.
The Sprinkler Advantage
Here's an interesting insight: if a building is equipped with
an automatic sprinkler system that meets the required standards, the limits on the size of fire
compartments (floor area or cubic capacity) can often be doubled. This is because sprinklers are highly effective at controlling a fire
in its early stages, reducing the overall fire severity and the likelihood
of widespread damage. This allows for more flexible and open building designs while still
maintaining a high level of safety.
Beyond the Basics: What Else to Know
Compartmentation is a complex system that integrates with many other fire
safety features:
• Smoke Control Systems: In open spaces like atria (large, multi-story open areas within a
building), physical compartmentation might not be fully possible. In these cases, advanced smoke control systems (using fans and vents to manage smoke movement) become critical to
maintain safe escape routes and prevent smoke from filling the entire
space.
• Evacuation Strategies: Compartmentation directly supports various evacuation plans, including
"progressive horizontal evacuation," where people move from a
fire-affected compartment to an adjacent, safe one on the same floor.
Your Peace of Mind
Ultimately, fire compartmentation might be an "invisible shield," but its
impact on your safety is very real and tangible. It's a proactive measure,
meticulously planned during the building's design, to ensure that in the
event of a fire, the structure itself acts as a first line of defense,
giving you the best possible chance to get to safety.
So, the next time you're in a multi-story building, remember the silent
work of its compartmentation – a testament to thoughtful design aimed at
protecting every occupant.
On Youtube - How Affordable Honeycomb High Rise can be 25% Cheaper to Build than a Conventional Design
This was my 12-minute talk at the Malaysian Urban Forum in February 2019 at KLCC Conference Centre. by Mazlin Ghazali. Providing every home with a private and a shared garden is the key to overcoming the social defects of high-rise and also to making them affordable.
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Cover
Contents
Title Page
Copyright
Dedication
Contents
Figures
Tables
INTRODUCTION
PART 1:
LOW-RISE HONEYCOMB HOUSING
6.2 A Big Site
PART II:
HIGH-RISE HONEYCOMB HOUSING
10.1
High-Rise Housing
13.1 The Singapore Experience
PART III:
AFFORDABLE HONEYCOMB HOUSING
Bibliography
Index
Notes
About the
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Reducing the Development Cost of High-Density High-Rise by 10 - 20%
The key inventive step in the Honeycomb apartment concept is
the elimination of corridors and replacing them instead with of sky-courts.
Re-inventing how residents are connected from the public street to their
individual apartments overcomes the social problems that have been linked to
the nature of corridors and “intermediate space” but also opens up to various
ways of reducing costs.
The chart below that breaks down the selling price of a
typical apartment helps us better understand by how much the checkerboard can
help make housing affordable.
Here the components that make up the price of a typical
apartment is listed with the bigger costs at the bottom. In this example, the
biggest cost factor is land followed by the cost of architectural works, profit,
car park, M&E services, superstructure, infrastructure, consultant’s fees,
bridging loan, substructure, preliminaries, marketing costs and contributions.
The key thing about the Honeycomb checkerboard-plan is that it
simultaneously attacks these multiple cost-centres:
From this list, all but two of the cost-centres mentioned above
have been affected. But these two factors – profit and consultant fees – are
calculated based on a percentage of development cost and when this has been
substantially reduced, so can the amount of profit and fees for consultants.
So, in both direct and indirect ways, we have shown that ALL the cost-centres
have been tackled by the checkerboard design.
This validates the strategy that we have adopted. To really reduce
the cost of homes to make them affordable, re-looking at the apartment typology
and re-designing it from first principles offers a way forward.
10 to 20% SAVINGS
All these cost-savings point to checkerboard-plan apartments to be
even cheaper to build than conventional high-rise.
A preliminary estimate of all the savings discussed above
indicates that it is possible for affordable housing below RM300 per square
foot to be provided in the major city centres where the price of land is within
RM300 per square foot and where the density permitted is 130 units an acre and
the parking standard is 2.2 car park per unit.
A COMPARATIVE STUDY
A study has been done to compare an actual project with a hypothetical Honeycomb alternative on the same site. We were able to enlist the help of the Quantity Surveyor of a real project near Putrajaya by PR1MA, a government-owned company tasked with delivering 500,000 affordable homes by 2020. At the time of writing, the project was at piling stage.
Instead of two
15-storey blocks with a separate 6-storey car park block, we just had five 8
storey blocks on the car parking all on the ground floor. Naturally, there was
a reduction in the construction cost per square foot of gross built-up area
(GFA): just over 9% from RM119 to RM109.
     The initial result shows that the potential savings are as substantial as we expected. The following table presents a summary.
The average Net
Saleable Area for each unit of only 88.11sm is increased by 21% to 106.75sm,
but allied with a slight reduction in Gross Development Area: the efficiency of
the layout, i.e. The Net Saleable Area as a percentage of the Gross Development
Area has greatly increased from 49% to 60%. This means that there is a huge
reduction in the construction cost per square foot of Net Sellable area of just
over 24.8% from RM242 to RM182!
In this
example, the Honeycomb alternative had a slightly lower density, 62 units per
acre instead of 70. But with bigger units the Net Plot Ratio slightly increases
from 1.52 to 1.56, causing a slight reduction in land cost per square foot of
saleable area. With the land priced at only RM80 per square foot, the effect is
not large.
However, with
important land component of development costs virtually unchanged, the large
reduction in construction cost has a more moderate effect on Selling Price: the
alternative design can be sold at the average price of RM273 per square foot
instead of RM323, a reduction of about 15%.
Table
2
A COMPARATIVE STUDY
This is well in the middle of our estimate
for the cost savings achievable by the Honeycomb Apartment layout compared with
conventional design. In this example, cost savings from construction was
maximized and potential cost savings from land was not exploited because the
land price was relatively cheap.
At RM80 per square foot, the potential
savings from land did not merit the added cost of adding more residential
floors and digging in a half basement car park. However, in cases where land is
more expensive, the calculation would yield a different result.
CONCLUSION
Architects are not well known for helping to cut the cost of
construction: it is said that every line an architect draws add cost. If so, it’s better that we not draw anything
at all, just let the engineers or builders do it.
I write this only half-jokingly because it is a very common
perception and, after these 20 chapters, I hope to have shown it to be wrong.
When I was one of several architects doing low-cost mass
housing work for in the late 90’s, the client had in mind that we adopt a
standard design and the design responsibility of each architect was to do the
make -up work on the façade to give some sort of identity to each project.
The hope at that time was that the standardized design of
housing units would allow Industrial Building Systems of constructions to be
adopted, taking advantage of the large numbers of repetitive elements to be
manufactured and assembled.
Speeding up construction time, minimizing wet trades on
site, taking advantage of economies of scale, manufacturing techniques and reducing
labour, especially the need for skilled labour, all these can surely help
reduce the cost of building homes. But we must take a realistic perspective.
The cost of constructing a house is an important cost centre
but it’s not the only one. There is the land to acquire, infrastructural
services to provide and many other development costs to bear. Even just looking at construction costs, IBS
mainly affects the cost of structural and wall elements, which in conventional
construction only makes up about half of the building cost.
If structure and walls make up only half of the building
cost and building cost contribute to only, say, 50% of the selling price of a
home, then an IBS method of construction that involves only structure and wall
directly attacks only a 24% component of the cost of construction, equivalent
to roughly 12% of the price that a buyer pays for the home. So, if an IBS
system saves 10% off the cost of structure and walls, this can only deliver a
1.2% reduction in price. From my experience, it is unrealistic to expect
savings of more than a few percent of the total construction cost.
So, whilst better methods of construction should be pursued,
we also must look for ways to reduce the cost of infrastructure, land and other
costs.
A CASE FOR MORE RESEARCH INTO NEW TYPOLOGIES
This is where design can help. Not just another iteration of
existing apartment typologies, but a more fundamental re-examination of how homes
have been designed. This is the basis of
our research into new typologies.
In our Honeycomb Townhouse concept, compared to terrace
houses, there is at least 50% more units on each acre of land and construction
cost is also lower due to the sharing of roof, suspended floor and foundation
between the upstairs and downstairs unit.
Compared to conventional terrace townhouses, both the upper
and lower-level units have gardens, two car parks and ample window openings for
all the rooms. We have shown at our project in Alor Gajah that if priced about
20% lower than a terrace house with the same floor area, people will buy them.
We have discovered through experience that five-storey
walk-up flat is the cheapest housing typology in Malaysia. However, the two
highest floors were hard to sell even when sold at the heavily subsidized prices.
The V-shaped Honeycomb Medium-Rise concept provides a very
inexpensive lift that only shuttles between the ground floor and 3rd
floor to serve all units, a communal courtyard for all, and private front-yards
for some units, at an attractive block layout that achieves a density that is
about four times that of terrace houses.
It is envisaged that if the typical apartment is priced
about 20% lower than a terrace townhouse and 40% lower than a terrace house,
people will buy them. This new concept might be suited at the edge of small
towns.
In the suburbs of major urban centres where developers must
provide low-cost housing, we have come up with the Kotapuri concept where the
low-cost and low medium cost housing, priced between RM42,000 to RM100,000 are
placed on top of shops. Although sold at a loss, the marginal cost of building each unit of low-medium cost unit is
lower than its price; the marginal cost of
building each unit of heavily subsidized low-cost unit is not too much higher
than its price. In this case, the shops pay for the land and much of the
infrastructure cost. In locations where there is no demand for offices above
shops, it is better to use the space above it to provide housing units that
liven up the area and provide housing for the people who tend the shops.
Designed and managed properly the commercial and residential
components can add value to one another. In this way, the subsidized houses are
located near amenities and public transport rather than shunted to the
furthest, least attractive corner of a development.
In the Honeycomb apartment concept, the key inventive step
is the elimination of corridors and replacing them instead with of sky-courts.
Re-inventing how residents are connected from the public street to their
individual apartments overcomes the social problems that have been linked to
the nature of corridors and “intermediate space” but also opens up to various
ways of reducing costs, making it possible to reduce pricing by up to 20%.
At the same time, we offer products that are more desirable,
that can overcome the major social defects of high-density high-rise housing.
In the last few years, private and public developers have
concentrated either on landed property that are expensive due to the escalating
cost of land or else on high-density high-rise block that are very expensive to
construct. These new low and medium-rise Honeycomb designs provide a wider range of alternatives that can serve an important
gap in the housing market between terrace houses and high-rise apartments that
most Malaysians cannot afford, and the subsidized low-cost and affordable
housing that either lose money or provide thin margins.
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