Facts

The plaintiff entered into 16 similar sale and purchase agreements ('the SPAs') with the first defendant whereby the plaintiff purchased 16 office lots in a building owned by the first defendant. The said 16 SPAs contain, inter alia, similar relevant clauses which are as follows:

Section 1.01(m):

'Service charges' which may be imposed by the defendants for the services provided by the defendants for the management, upkeep and maintenance of the building including the plaintiff's 16 office lots and 'service charges' include costs of electric power and water supply.

Section 5.01(a):

Provides that the plaintiff shall upon the defendants' demand pay to the defendants the quit rent and assessment on the plaintiff's 16 office lots.

Section 5.01(b)(1):

Provides that the plaintiff shall be liable to pay the defendants for the service charges for the maintenance and management of 'the common property' as defined in clause 1.01(1).

Section 5.01(b)(2):

Provides that the plaintiff shall pay service charges and a contribution to 'the sinking fund' at the rates specified in section 6(a) and (b) of Schedule A to the SPAs.

Sections 4.05 and 10.13:

Provide that time shal