What is the basis for calculating a sum to be omitted when the Contractors bid (and the contract) contained an error?

Asked 7 months ago
2020-04-28 19:54:45

Under a JCT DB 2016 an Employer has varied the works and specified a certain manufacturer of an expensive type of street lights to be procured and installed. The instruction occured before the Contractor had made any design submission, which would have been the cheapest possible compliant light because the Contractor, whilst having been deemed to have allowed for lighting to minimum legislative and ilumination standards as set out in the Employers Requirements, in fact made an error and included no sum of money in its bid or the contract.
The Employer has sought to value the variation ( or Change) at zero stating that the Contractors bid must have included for something similar whereas in fact cheaper lights would suffice and still have served the purpose - but the Contractor has lost this opportunity to minimize its losses due to the Change. How can the Contractor demonstrate that at least some reasonable but relatively low theoretical cost allowance must be used to establish a reasonable extra over for the approved lights, or can the Contractor expect to receive 100% of the net cost of the new specified expensive lights, or can the Employer simply be allowed to pay nothing for the net work cost of the Change citing that the Contractors bid must have included enough to cover the lights which would mean the Contractor is not only losing on a cheaper lights but also now losing more as a result of an Employer instruction ( there is no dispute over time and loss/expense in this case, and the ERs only included minimum illumination standards that many different products could achieve).