Table 3: Summary of the cost of the strengthening/retrofitting approaches.

Methods		Cost
To reduce force	Base isolation	It is very expensive to install. It costs about 3% of total construction cost to install a new hybrid base isolation system.
	Seismic damper	It is very expensive to apply seismic damper. Furthermore, this technique requires advanced equipment and techniques.
To upgrade the existing buildings	Surface treatment	It is expensive to install as it requires special equipment as well as manufacturing of concrete and use of steel.
	Mortar joint treatment	It is cheap to use this technique as the mortar and masonry units are easy and cheap to obtain.
	External steel reinforcement	It requires relatively high cost because of the steel usage.
	Post-tension	This technique is somewhat highly costly.
	Mesh reinforcement	It is expensive as FRP is 5 to 10 times more expensive than steel.
	Reticulatus system	It is cost-effective as it requires small portion of reinforcement mesh and some re-pointing mortar.
To improve the integrity	Constructional columns	It is expensive to apply this technique as it requires demolition and reconstruction on the original structure.
	Ring beams	It is expensive to construct ring beams on URM structure.
	Tie bars	The cost of this technique is close to that of post-tensioning
	Fibre/textile-reinforced mortar	The cost of this technique is somewhat cheap as only mortar and fibres should be considered.