Building Services

This is E-Learning page for students undergraduate from Centre of Studies for Quantity Surveying Department. This page cover the plumbing system, typical appliances, water storage, direct and indirect system, zoning system and hot water supply.



Definition of Plumbing System

The system of pipes, drains, fittings, valves and fixtures installed for the distribution of portable water for drinking, heating, washing and for waste disposal.

The water system design must comply with Water Authority requirements.

Assessment of the application from the users or clients should contain of the following ;

  1. Number of flats/units in each block of the building
  2. Address of each premise need individually metered water supply
  3. Number of draw-off points and sanitary fittings in each unit
  4. Estimated daily consumption for all trade purposes

However, for water demand depends on the followings ;

  1. Type of building and its function
  2. Number of occupants permanents or transitional (domestic, commercial and educational buildings)
  3. Requirement for fire protection systems
  4. Landscape and water features


Typical Appliances Using The Cold Water

Typical appliances using the cold water system as follow;

  • Water closet, wash basin, bath, shower, sink
  • Washing machine, dishwasher
  • Urinal flushing cistern

Water closet

Wash basin






Water storage need to be install at the area of development and also in the building itself. 

Recommended Minimum Storage of Cold and Hot Water System

Figure 1 shows recommended of minimum water storage for cold and hot water system. Difference types of building have a difference standard of water storage for cold and hot water system.


High-rise Plumbing System

High-rise plumbing usually uses vertical piping systems in terms of water distribution and drainage or venting system. The installation of piping system should consider of the pressure distribution.

A suitable pressure distribution for the fixtures is usually not higher than 25 psi for water closet and supplied with flush valve fixtures. The reason is to limit the water velocity below critical values for noise consideration and to avoid erosion of piping, damage to fixtures and equipment and excessive equipment cost. The objectives of an engineer is to have a system where the pressure is controlled, usually by either placing pressure reducing valves on each level where pressure exceeds the code maximum or branching from the higher pressure riser to make a pressure zone. This pressure zone uses a central pressure-reducing valve and sub-riser to meet the minimum pressure required at the highest level and the maximum pressure allowed at the lowest level. This method of installation has been used for high-rise building design.

Other considerations for water supply distribution for high-rise building :

  • Available municipal water pressure
  • Pressure requirements at different floor throughout the building and at the upper floor
  • Flow demand
  • Booster pump capacity and control
  • Pipe and valve materials
  • Riser locations
  • Pressure zones
  • Pressure regulating stations
  • Water heater storage capacity
  • Water heater locations
  • Domestic hot water circulation or pipe temperature maintenance
  • Space requirements in the building
  • Economics
  • Energy efficiency and acoustics.


Zoning System is a method introduced to avoid excessive pressure, several schemes have been developed over years to achieve an economical, efficient and safe installation.

Single Zone

  • System tank allocate at the top and will distribute the flow of water to the bottom.
  • Distributed using gravity down feed arrangement.
  • Rarely used due to the risk of overloaded of water storage and dangerous to the occupants.

Multiple Zone

  • Multiple tank were used, one at high zone and the other one at low zone.
  • An air gap creates break in between the upper and lower zones.
  • The tank must be sufficiently elevated for adequate pressure at the first floor connected.

Multi-Zone Cold Water Distribution with Multiple Pumps

  • Multiple booster pumps with constant-speed, constant-pressure control were utilised, with one pump for each zone.

Pressure Regulating Valves

  • Separating building into zones.
  • With pumped system, the supply pressure to the lower zone is controlled by pressure regulating valve (PRV), and the pump discharge pressure is set for the supply to the upper zone.
  • Another alternative is use the tank as the source, and continue to control the lower zone pressure with a PRV.

Variable-Speed Pumps System

  • Can reduce the energy consumption over the life of the system while increasing system life by years.
  • This is due to the constant water pressure is desired in the building.
  • The advantage of using variable-speed booster pump systems,
  • Can reduced equipment and energy costs
  • The elimination of water hammer and surges found with most constant speed systems.
  • Variable speed’s ability to maintain accurate pressure settings.


Hot water can either be generated through central boiler plant and stored and local.

Central Boiler Hot Water Supply

The central boiler system is used for houses, hotels, offices and flats. Basically the sources of energy used to boiler the water either from solid fuel, oil, gas or electricity. The distribution of hot water supply is to distribute through straightforward vertical distributing pipe system with short draw-off branches leading to taps to sanitary appliances for both anticipated peak demand and during the recharge period. The disadvantages of this system is that there are some loss of head from the distributing pipes and if the sources of energy from electricity, the cost of usage will be very high. Figure 2  shows hot water system.

Local Hot Water Supply

This method used a water heater, adjacent to the fittings to be supplied. The sources of energy ether from gas or electricity. The water is either heated or stored locally or heated instantaneously as it flows through the heater, the advantages of the system is the minimum usage of pipework.

Hot water Supply Heaters

The local hot water storage heater consists of a heat source and a storage cylinder or tank, and the instantaneously as it is run off. The larger water storage heaters are used to supply hot water to a range of fittings such as basins, showers and baths. The storage heater is heavily insulated to conserve energy. The size of the heater is determined by the anticipated use of hot water at times of peak use. A thermostat or switch operate the lower immersion heater. An advantage of this system is that it does not have to be fixed close to the wall. 

Figure 3 : Water storage heater

Figure 4 : Floor standing water heater storage


What is plumbing system?

  • A system for the collection, transmission, treatment, storage and distribution of water from source to consumers.
  • A system of pipes, drains, fittings, valves and fixtures installed for the distribution of portable water for drinking, heating, washing and for waste disposal.
  • The process of removing contaminants from wastewater, primarily from household sewage.

Choose the correct design for water storage (multiple answer)

  • Frequency
  • Patterns of use
  • Economics
  • Type and number of fittings
  • Space requirements in the building
  • Likelihood and frequency of breakdown of supply

Which one is define as direct system?

  • The system of water supply direct to the water tank.
  • The system of water supply direct from the main to the kitchen.

This system tank is allocated at the top and will distribute the flow of water at the bottom. The water is distributed using gravity down feed arrangement. Which is true about that?

  • Single Zone
  • Multiple Zone
  • Multi-Zone Cold Water Distribution with multiple pumps
  • Pressure Regulating Valves
  • Variable-Speed Pumps System

Which of the following is indirect system?