The success and final
outcome of this assignment required a lot of guidance and assistance from many
people. We are fortunate to have guidance and help and we would not forget to
thank them for their full support.
First of all, we would like
to express our great appreciation and thanks to our lecturer, Dr. Sr. Fara Diva
binti Mustapa who gave us an opportunity to implement this assignment on the
topic “Design Variables that Effect on Building Cost” and gave a lot of
guidance while we are doing this assignment. Without her guidance and help,
this assignment would not have been possible for us to be completed.
Furthermore, we have learned many new things and knowledge while doing research
for this assignment.
Next, we would really like
to express our deepest gratitude to our parents because they gave us a constant
encouragement and support in moral and financial to carry out this task well. A
special notes of thanks to all our classmates who took keen interest in our assignment
by providing and sharing all necessary information and idea to complete this assignment
properly until the last date of
submission. Without them, this project would have been a distant reality.
Finally, we realize that by doing this
project, it was not just to get points and good grades, but also to increase our
knowledge in this course of which we have learned.
The issue of construction
work costs is one of the issues that does not run away from the minds of
construction clients, design teams, builders and, of course, quantity
surveyors. The cost of constructing a building project is a major concern for
the majority of construction clients. Indeed one of the most common startup
questions clients have is “what will impose me?” often followed by
“can we do it cheaper?”.
Providing answers to such
questions is the main objective of the quantity surveyor, whose job it is to
predict the possible cost of building work and to manage the project’s evolving
project to ensure that the estimate of the customer’s budget does not exceed.
This is a challenging task, which often involves one, one unique, the purpose
of building a building, and QS usually operates in a design team brought
together for the project.
Customers are often aware of
the cost of their building. The indicative cost ranges for various types of
development are often published by practice of greater quantity measurement and
are also available in construction price books. In this situation, QS needs to
explain that the cost of construction work is influenced by various factors.
Most of these factors are
interconnected and one of them is the building’s own design variables. Building
geometry has a huge impact on costs. The morphological building is concerned
with the size, shape and complexity of the building. The purpose of quantity
surveyors in this process is to maximize customer’s value for money.
On this paperwork, factors of design variable that give
impact on building cost will be described in details by comparing three units
of 3-storey office building which includes corner unit, intermediate unit and end
unit. The table below shows the project description that has been chosen to
carry out this assignment.
3.0 DESIGN VARIABLES THAT AFFECT BUILDING
3.1 CHANGES OF STOREY HEIGHT
Variations in storey height
are one of the factors that will cause change in building cost. For example,
the increase in building height influences building cost even with the same
gross floor area or not. The difference in construction and maintenance cost is
more obvious especially influenced by vertical building components.
As per our project, the
height of corner unit, intermediate unit and end unit is 11.40m. If the storey
height changes higher than 11.40m, it surely will affect the building cost in a
lot of aspects of part of the building. Followings are the major costs that
will also change when the storey height increase:
The structure, construction
cost of frame or the height of column will increase due to the changes of height
and load of storey of building.
As we could notice that the
construction cost for the foundation of building for the three types of storey
units will increase due to increasing of load in foundation. The size of
foundation will be bigger and will using a safer system such as the use of
piling. This means and increase in the cost of construction will occur.
The construction cost will
increase due to increase of height from one storey to another storey.
The quantity of using
external and internal brickwall will increase due to the changes of height of
building. The quantity of wall finishes also will increase.
The cost of ceiling
construction, finishes and upper floor increase due to increase in the aspect
of rate of labour and vertical transportation cost (needs plant and takes more
time). Besides, the installation of scaffoldings also will increase. This will
affect the construction cost of the building.
M&E system and piping
As the spatial volume of the
building increases, it will need a system that is of higher capacity for
cooling proposes. Furthermore, the installation cost of electrical wiring and
piping for water supply, the length Rain Water Down Pipe (RWDP) will increase.
Increase in storey height
will affect the building maintenance cost such as repainting works, operation
cost for mechanical and electrical system.
As we could see, the overall
construction cost will increase with the increase in total height of building
or with the increase of storey height. The construction cost for a high
structure is more than that for a low building that provides and offers the
same GFA. However, a high type of building is necessary to build if the land area
is limited and too expensive.
115mm External Brickwall
115mm Internal Brickwall
115mm External Brickwall
115mm Internal Brickwall
115mm External Brickwall
115mm Internal Brickwall
Table 1: Cost comparison
causes by changes height of brickwall between each unit of 3-storey office
One of the main elements that
includes in substructure is foundation. Foundation of the building is really important as a
component of the structural interface between the building and the support
ground. It performs an important function to transmit building
loads including wind and earthquake impacts that make soil strata as a support without any shear failure or excessive placement.
The properties of the soil
will determine the strength of the soil. Mark and Halliburton
(1972) emphasize that the strength of clay-soil mixtures depends on many
variables such as soil type, lime content, curing time, water content,
compaction method and cost. Mark and Halliburton (1972) also found that increasing temperatures on the curing of limestone
soil caused increased strength. If the land is swamped there will be a rising
cost because the base type will be changed from the base of the strip to the
base of the inner band which will increase the cost of the substructure. If the
soil is a rocky area, it depends on the depths that lie on the rock, if the
rock is located on the surface, which requires a little explosion before
The selection of a suitable base system for multi-storey buildings like our selected project which is 3-storey office lot, generally is controlled by some factors which are:- 1. Building loads. Each unit which is end unit, intermediate unit and corner unit has different loads to be carried due to its building size. This does affect how big or small the substructure is for each unit. 2. Wind and earthquake effects. The location of these units also effect on the substructure cost due to the wind and earthquake effects. The corner unit and end unit must come with a good substructure to withstand these kinds of effect because of its location that located at the very end of whole units.
3. Soil profile. Soil profile especially on soil settlement is very important in choosing the best substructure to be used for each unit especially the material to be used to construct the substructure. This is because without considering this factor, the building will collapse due to the settlement of soil. 4. Water table conditions. By checking the water table conditions before doing the substructure, the best substructure to be constructed for each unit can be perfectly selected to avoid any problems occur in future such as building collapse. 5. Chemically aggressive soil conditions. Soil survey must be carried out before the substructure being constructed to detect any chemically aggressive soil conditions. This is very important because corrosion will occur on the substructure of each unit if there is no action been taken to solve this problem. 6. Existing buildings.
Before the substructure being
construct, existing buildings must be recognized to avoid any discrepancies or
problems occur for example when choosing the best method in constructing the
foundation to avoid existing buildings receive any defects from the construction
Based on these factors, the engineers have designed the most suitable foundation for each unit which are end lot, intermediate lot and corner lot. On the next page, comparisons have been made between these three units to differ cost of substructure for each unit. The cost for each unit is differing due to the different types of foundation used and the method of construction for the foundation itself.
Total Cost of Substructure
Table 2: Cost comparison for substructure between each unit of 3-storey office lot.
Windows are connecting the interior
of the house to the outside of the house. It provides a good ventilation and
daylight from sunlight to brighten the building besides they also provide the
lowest insulation value in the building envelope. Windows are important aesthetic
elements in a building. Indirectly, it has become a centre of public attention
and attraction in terms of design architecture.
Windows come in many types of material such as steel, aluminium, plastic, timber and stainless steel. Each of these materials has its own economic factors. There are few factors of windows that give impact on our cost of 3-storey office lot which are:- 1. Quantity. The number of windows definitely effect on cost of building because of the price to buy and install the windows. The higher the quantity of windows, the higher the cost of building. The corner unit requires a lot of windows because of its open location area. 2. Type of material used. Types of material that are being used for windows in a building also give effects on cost. They are comes with many types such as timber, aluminium, steel and etc. Each of these types has different costs due to its different material type so automatically the building cost will get affected when different type of windows are used. Besides, timber or steel windows needs some kind of preservative and decoration and these will also effect on building cost. 3. Size. A well-designed building considers how big enough the size of each window that is required for a good ventilation and daylight. Besides, the size of windows also gives effect on building cost. Basically, small windows size has a high cost/m²GFA that will impact the cost of building directly.
4. Location. The perfect locations to be arranged for windows are very important to avoid any area from not getting enough daylight or good ventilation. Besides without a perfect and strategic location, more windows are used to cover up certain area especially corner unit that require a lot of windows. 5. Performance.
The performance of window whether
the manufacturing quality is good or not, weatherproof and ironmongery used for
the window installation also being considered as one of the factor that affect
cost of building. Cost will also increase for each office unit if there are any
sliding windows used and either the windows comply with safety requirements.
Based on these factors, a good consideration will be apply during designing the windows and doors on our 3-storey office building so that it is become a cost effective. On the table 4 in the next page shows that comparison of windows cost between each unit in 3-storey office building.
Number of Windows
TOTAL NO. OF WINDOW
TOTAL AREA (m²)
TOTAL COST (RM)
Table 3: Cost comparison for windows between each unit of 3-storey office lot.
Floor finishes is a material
used as the final layer of a floor to provide a walking surface. The choices of floor finishes are
likely depending on class and type of the building. There is various type of floor finishes
generally used for Shop Lots, which is listed as below: –
1) Cement Render
2) Vinyl Tile
3) Tiled Flooring (Ceramic Tiles)
4) Timber Laminate Flooring
Type of Floor Finishes
– Advantage and Disadvantages
Type of Floor
Cheapest and very basic type of flooring
Less attractive in its appearance
to tiles and any other type of floorings
contents in the final mix may lead to cracks on the finish
Very durable, fast to
construct, easy to clean, less maintenance and environmental friendly.
Require flat and smooth surface to work on.
Durable if properly
installed and maintained. Comfort underfoot. Ease of installation and easy to
care for. Low maintenance, water and stain resistance.
Wear down and tear
off easily. Not resistance to chemical stain. Cannot be refinished or
repaired when it is damaged
Tiled Flooring (Ceramic Tile)
Available in various textures, colors and sizes.
Expensive in materials and labour
Also very durable. Suitable for high traffic areas. Resistant against water, fire
Cleaning with any
strong detergent may still causing damage to the tiles such as color fade,
Require better workmanship and longer time
Type of Floor Finishes
– Advantage and Disadvantages (Cont’d)
Type of Floor
Timber laminate flooring
with various patterns to choose from.
Excessive water can
damage the surface; too much exposure to the sunlight may also cause damage.
Simple to install, easy to clean and
Less durable than
cement render and tiles. Limited Warranty up to 15 years only, may expose to
termite threat after the expiry of warranty.
Comparison of cost
Type of Floor
Vinyl Tile (2mm thick)
Tiled Flooring (300mm x 300mm Ceramic Tile)
Timber laminate flooring (8mm thick)
Flooring Option for Shop Lots
the table 1 & 2, we analyze that the most economical material used as floor
finishes for the shop lots is cement render. In term of its cheaper pricing,
cement render appears to be the most suitable choice for the Shop Lots, mainly
due to the following reasons:
1) Compliance with Authority’s
2) Fulfil the basic need
for every type of business because of its strength and durability, it will not
fade and wear off easily.
3) Cold characteristic
and does not retain heat hence suitable for tropical countries.
4) Allowing the buyers to choose their preference floor finishes for their nature of
business. Leaving the buyer a lot of design freedom because of its versatility.
that the construction industry continues to be one of the fastest growing
sectors in any economy, whether in developed or developed countries, the desire
to deliver the best product output in terms of well-designed construction
projects, which can meet customers and end users can be emphasized.
effect of the cost of the main design variables has been checked and compared
between three different units of 3-storey office buildings. Conclusory, building
costs are influenced by various factors, partly interconnected with each other.
It is very important that quantity surveyors should be aware of the
consequences of costs due to changes in shapes, windows, storey height,
substructure, finishes and other building features.
generally arguable that larger buildings with simple, rectangular and simple
rectangular designs will be cheaper per sq.m. of floor area of ??smaller
building, shaped, curved or corner complex. The allocation of economies of
scale imposes higher costs into a “productive” space. A simple and
easy solution encourages the use of larger plants and generates higher
productivity and less waste. 9 The complex layout and details are slower to
install and may involve some trade with greater risk of errors and defects. The
separation and repetition levels will also affect the overall cost of work.
Ø Building ECA
Ø Project Drawing Layout