S. Ravindra Bhat, J.

All three appeals impugn separate orders passed by the learned Single judge on applications filed by the respondents under Section 34 of the Arbitration and Conciliation Act, 1996 (hereafter, "the Act"). The common strain in all the appeals is that since the respondents/contractors had accepted the final bills without protest, their claims could not have been entertained. The awards granted in favour of such respondent/claimants (hereafter collectively "claimants", "contractors" or by their names, i.e. "Sukumar, "GSC" and "Kuber").

Facts:

FAO 431/2012

2. The correctness of the learned single judge's order and judgment, in OMP 399/2007 preferred by the respondent Delhi Development Authority (hereafter referred as "DDA") under Section 34 of the Act is questioned in this appeal. DDA had challenged an award dated 15.12.2006 of the sole arbitrator in the disputes between it (DDA) and claimant, Sukumar. The claimant was awarded the work of construction of 8314 houses in Sector-XV, Rohini, Delhi, SH & Construction of 252 LIG houses in Pocket Nos. 6 & 7, Block- G, Sector XV, Rohini, Delhi by DDA by letter dated 16.12.1985. An agreement bearing No. 15/EE/RPD-II/85-86 was executed between the parties. The work was to be completed within 12 months from the date of commencement which was 26.12.1985. Under the letter of award, the work consisted of two schemes, viz. Scheme No. 31 and Scheme No. 35-A. The stipulated date of competition was 26.12.1986. The awarded work was completed by the claimant on 30.08.1991 and the DDA extended time up to this date without levy of compensation. Due to the failure of the DDA, the work could not be commenced till 17.01.1986 (Scheme No. 31) and 20.01.1986 (Scheme No. 35-A). Further, the layout plan, foundation and other drawings were not provided to the claimant before the said dates. Cement and steel too were not made available to the claimant by DDA within time. The claimant sought compensation, which was denied. The resultant disputes were referred to the arbitrator. The claimant invoked the arbitration clause by letter dated 26.06.1993 and by an order dated 22.10.2003, this court appointed Justice J.K. Mehra (Retired) as sole arbitrator. The Tribunal passed an award dated15.12.2006 after hearing both the parties to the dispute. This was challenged by the DDA in the year 2007 under Section 34 of the Act. DDA's contention was that the claimant could not claim damages on account of delay, because it had, in the extension of time proforma, agreed not to do so. The Tribunal rejected this defense and relied on the decision in Bedi Construction v. Delhi Development Authority, 1995 1 ArbLR 575. The Tribunal rejected Sukumar's plea that the final bill was accepted by DDA in full and final settlement and held that payment of only undisputed items was made by the DDA on 05.06.1993 and with respect to the remaining claimant, without delay, it invoked arbitration on 26.06.1993.

3. These findings had not been challenged by the DDA. DDA had challenged the award in respect of Claim nos. 1, 2, 4, 8, 9, 14, 15, 17B-H and 19. For claim No. 14, the arbitrator awarded Rs. 4,00,000/- on account of extra expenditure due to overheads etc. for prolonged periods. DDA's objection that such amounts could not be awarded, because the claimant had accepted previously, the amounts given and given up any claim for further amounts, was rejected; the Tribunal held that:

"After considering the contentions and the pleadings of the parties including the submissions made in writing, the oral submissions and the case law it is clear that such recording by respondent on the performa of the extension of time up to 31.8.1991 is not with free consent and on this basis the claim of the claimant because of prolongation of the contract period cannot be disallowed."

4. Before the learned single judge, the contractor contended that it had offered four rebates on the estimated cost of Rs.56,09,304/-. 1% on running bills if mont