Contracts, tenders and specifications

Civil Engineering (B.E./B.Tech) · Construction management · free study notes for exams, placements and interviews

In short

A construction contract is a legally enforceable agreement in which a contractor executes defined work for an owner at an agreed price, time and quality, governed in India by the Indian Contract Act, 1872. Tendering is the competitive, documented process by which that contractor is selected, and specifications are the written statement of materials, workmanship and acceptance standards that define "quality" in measurable terms. Together they decide who builds, for how much, and to what standard — so disputes, claims and cost overruns almost always trace back to a defective contract clause, tender condition or specification. The topic carries steady marks in Construction Management and Estimating papers and in state AE/JE and PSU recruitment exams (GATE Civil's construction management section is limited to project planning and network analysis), and is tested heavily in interviews for CPWD, PWD, NHAI, railways, L&T, Tata Projects, Shapoorji Pallonji, AFCONS and consultancies, where junior engineers handle NITs, BOQs, measurement books and running account bills from day one.

Explained

Contract: legal basis and contract documents

Contract (Sec. 2(h), Indian Contract Act, 1872): an agreement enforceable by law — i.e. proposal, acceptance, consideration and intention to create legal relations.
Essentials of a valid contract: offer and acceptance; lawful consideration; competent parties (Sec. 11 — major, sound mind, not disqualified); free consent (no coercion, undue influence, fraud, misrepresentation, mistake); lawful object; not expressly void; certainty of terms; possibility of performance.
Void, voidable, illegal: a void agreement has no effect from the start (wager, impossible act); a voidable contract is valid until the aggrieved party rescinds it (consent obtained by fraud); an illegal agreement is void and also punishable.
Breach and remedies: damages (Sec. 73 — compensation for loss naturally arising), liquidated damages / penalty (Sec. 74 — reasonable compensation, not exceeding the stipulated sum), specific performance, injunction, quantum meruit for work actually done.
Parties: Owner/Employer, Contractor, Engineer-in-Charge (administers the contract, certifies measurements and payments), Consultant/Architect, sub-contractor (only if permitted; main contractor stays liable).
Contract documents (read together; a priority-of-documents clause resolves conflicts): agreement/contract deed, notice inviting tender (NIT), tender/bid form and letter of acceptance, general conditions of contract (GCC), special conditions (SCC), technical specifications, schedule of quantities (BOQ) with rates, drawings, bill of materials, schedule of issue of materials and machinery, time schedule, safety and labour conditions, correspondence incorporated by reference.
Essentials of a sound contract document: unambiguous and complete scope; realistic quantities and time; clear payment and measurement basis; defined risk sharing (variation, escalation, force majeure); dispute resolution mechanism; no contradiction between clauses.

Types of construction contracts

Item rate (unit price / schedule) contract: contractor quotes a rate per item; payment = actual measured quantity × quoted rate. Most common in Indian government work. Suits well-defined work with uncertain quantities; owner bears quantity risk, contractor bears rate risk.
Percentage rate contract: owner gives the BOQ with its own rates (e.g. the departmental Schedule of Rates); bidders quote a single percentage above or below. Prevents unbalanced bidding and arithmetic errors; limits contractor's pricing freedom.
Lump sum (fixed price) contract: one fixed amount for the whole work against complete drawings and specifications. Needs a schedule of rates only for valuing variations. Owner's cost is certain; needs fully frozen design, else heavy variation claims.
Lump sum with schedule of rates: hybrid — lump sum for defined scope plus a priced schedule for additions and deletions.
Cost plus contracts: owner reimburses actual cost and pays a fee. Variants — *cost plus fixed percentage* (fee grows with cost, no incentive to economise), *cost plus fixed fee*, *cost plus fluctuating fee* (fee falls as cost rises), *cost plus with guaranteed maximum / target cost* with savings shared. Used for emergency, repair or undefined-scope work; needs strict audit of vouchers.
Labour contract: contractor supplies only labour and tools; owner supplies materials. Common for small items and departmental work. A piece-work agreement is distinct — only a rate per unit is agreed, with no total quantity or completion time stipulated.
Target contract: target cost and time fixed; savings or overruns shared in an agreed ratio.
Turnkey / EPC contract: single agency does engineering, procurement and construction and hands over a working facility; design risk shifts to the contractor. Standard for NHAI highways, metros and power plants.
Design–build, Item-rate vs EPC vs PPP: PPP concession models — BOT (Toll), BOT (Annuity), DBFOT, Hybrid Annuity Model (HAM — authority funds 40% during construction, 60% as annuity with interest), TOT (Toll-Operate-Transfer) for monetising built assets.
Rate contract / running contract: agreed rates for supply of specified materials over a period, quantity not fixed (DGS&D-type, now largely through GeM).
Negotiated contract: single capable agency negotiated with, without open competition — allowed only in limited circumstances; CVC guidelines discourage post-tender negotiation except with L1.

Tenders: types and step-by-step process

Tender: an offer in writing to execute work at a stated price; it becomes a contract only on acceptance communicated to the tenderer.
Types by competition: open tender (public advertisement, maximum competition; global/ICB when foreign bidders are invited), limited/selective tender (from an approved panel), single tender / nomination (proprietary or emergency), negotiated, two-stage tender (technical concept first, then price), reverse auction (online downward bidding, common on GeM).
Types by submission: single-bid, two-bid/two-envelope (Technical + Financial, financial opened only for technically qualified bidders), three-envelope (EMD + technical + financial).
Process:
Administrative approval, technical sanction and estimate; decide contract type and packaging.
Pre-qualification (PQ) for large works — turnover, similar-work experience, bid capacity, plant, key personnel, solvency certificate, litigation history.
Notice Inviting Tender (NIT): name and scope of work, estimated cost put to tender, EMD, cost of documents, time of completion, dates of sale/submission/opening, eligibility, place of inspection.
Publication — mandatorily on the Central Public Procurement Portal (eprocure.gov.in) / state e-procurement portals / GeM for goods and services, plus newspapers above threshold; e-publication is required by GFR, 2017.
Issue of documents and pre-bid meeting; clarifications issued as addenda/corrigenda to all bidders.
Submission with EMD/bid security (or a bid-security declaration, now permitted in place of EMD in many central procurements) before the deadline; digitally signed and encrypted in e-tendering.
Opening: technical bids opened in presence of bidders/representatives; a comparative statement (tender scrutiny sheet) is prepared.
Evaluation: responsiveness check, arithmetic correction, rate analysis of abnormally low/high items, qualification check, loading for deviations; L1 is the lowest evaluated responsive bid (QCBS — quality-cum-cost-based selection — is used for consultancy, where technical score is weighted with price).
Acceptance: approval by the competent authority, Letter of Acceptance (LOA)/work order, performance security and additional performance security for low bids, signing of the agreement, handing over of site, notice to proceed.
Unsuccessful bidders' EMD refunded; records retained for audit.
E-tendering advantages: wider reach, no cartel-friendly physical opening, audit trail, lower cost and time; needs DSC, bandwidth and bidder training.
Earnest money deposit (EMD): usually about 2% of estimated cost (slabs and ceilings vary by department); forfeited if the bidder withdraws or refuses to execute the agreement.

Conditions of contract, securities and payments

General Conditions of Contract (GCC): standard clauses applying to all works of that department — time of completion, extension, variations, measurement and payment, materials and workmanship, insurance, labour, termination, arbitration.
Special Conditions (SCC): work-specific clauses that override the GCC — site constraints, traffic diversion, working hours, special testing.
Standard forms in Indian practice: CPWD forms (PWD Form 7/8, Works Manual), MoRTH/NHAI model EPC and HAM agreements, Indian Railways General Conditions of Contract, FIDIC suite internationally — Red Book (employer-designed construction), Yellow Book (plant and design-build), Silver Book (EPC/turnkey) — with the Engineer and claims/dispute board procedures.
Securities and deductions (typical; exact percentages vary with department and must be read from the NIT): performance guarantee ≈ 5% of contract value as a bank guarantee; security deposit/retention ≈ 5% recovered from running bills and released after the defect liability period; mobilisation and plant advance (interest-bearing, against bank guarantee); income tax TDS and GST TDS as applicable; labour cess 1% under the Building and Other Construction Workers' Welfare Cess Act, 1996.
Measurement and payment: work recorded in the Measurement Book (MB) — a legal document, in ink, no erasures — as per IS 1200 (modes of measurement, part-wise); running account (RA) bills at agreed intervals; on-account payment for unmeasured work; final bill after completion certificate; no-claim certificate usually taken with the final bill.
Time clauses: time of completion and milestones; extension of time (EOT) for owner's delay or force majeure; liquidated damages/compensation for delay (commonly 0.5% to 1% of contract value per week, capped at about 10%); force majeure; price escalation (CPWD clause 10CC-type / MoRTH price adjustment) linked to published indices; variation/deviation clause with permissible limits and rate derivation for extra items (from BOQ rates, Schedule of Rates, or market rate analysis).
Defect liability period (DLP)/maintenance period: usually 12 months (longer for specialised works) during which the contractor rectifies defects free of cost; part of security is released only after it.
Termination, risk and cost: on default, the owner may rescind and get the balance work done at the contractor's risk and cost, recovering the excess.

Specifications

Specification: the written description of materials, workmanship, construction method, tolerances, testing and acceptance criteria, supplementing the drawings (which show shape and dimension).
Purposes: define quality and scope; form the basis of rate analysis and estimation; allow fair comparison of bids; form the legal yardstick for acceptance or rejection; guide execution and inspection.
General specification: a brief statement of the class of work and principal materials for each item of a building (e.g. "RCC framed structure, M25 concrete, Fe 500D steel, brick infill in CM 1:6, vitrified tile flooring") — used for preliminary estimates.
Detailed specification: item-by-item description of material quality, proportions, workmanship, method, tolerances, curing, tests, measurement and payment basis — part of the contract.
Classification by drafting approach: prescriptive/method specification (states materials and procedure; owner carries performance risk), performance/end-result specification (states the required outcome, e.g. pavement roughness or concrete strength; contractor chooses the method), proprietary specification (names a brand — avoided in public tenders, or qualified with "or equivalent approved"), reference specification (adopts an IS code or standard specification by reference).
Essentials of good specification writing: simple, unambiguous language; metric/SI units; no contradiction with drawings or BOQ; reference to current IS code numbers; tests and frequency stated; acceptance tolerances quantified; measurement clause for every item.
Indian standards and documents commonly referenced: National Building Code of India, 2016 (SP 7); IS 456:2000 plain and reinforced concrete; IS 10262 concrete mix proportioning; IS 2212 brickwork; IS 1200 measurement; IS 800 steel structures; IS 1893 seismic design; CPWD Specifications and CPWD Works Manual with the Delhi Schedule of Rates (DSR); MoRTH Specifications for Road and Bridge Works and the MoRTH Standard Data Book for roads; IRC codes for bridges and pavements; railway and state PWD standard specifications. Code editions and SOR years are revised periodically — always quote the edition named in the tender.

Statutory and regulatory framework, and disputes

Procurement rules: General Financial Rules, 2017 (Rules 142–178 on procurement, e-publishing, bid security, performance security); Delegation of Financial Powers; CVC circulars on tendering transparency; Public Procurement (Preference to Make in India) Order, 2017 with local-content classes; MSMED Act, 2006 reservations and exemption from EMD; GeM for goods and services.
Other applicable law: GST on works contracts (a composite supply of service — rates have been revised more than once, including the withdrawal of the concessional rate for many government works, so apply the notification current at bid date); Income Tax TDS u/s 194C; Contract Labour (Regulation and Abolition) Act, 1970; Building and Other Construction Workers (RE&CS) Act, 1996 and the Welfare Cess Act, 1996; Code on Wages, 2019 and the other labour codes (notification phased — confirm the status in force); Legal Metrology for measurement; Limitation Act, 1963 for claims.
Dispute resolution ladder: engineer's decision → amicable settlement/mediation or conciliation → Dispute Adjudication Board (FIDIC/NHAI contracts) → arbitration under the Arbitration and Conciliation Act, 1996 (amended 2015, 2019 and 2021 — time limits for award, arbitrator fees schedule, limited court interference, unconditional stay on an award where fraud or corruption is shown prima facie) → court. The Micro, Small and Medium Enterprises Facilitation Council and the government's Vivad se Vishwas-type settlement schemes are alternative routes.
Common claim heads: extension of time with prolongation cost, idle machinery and labour, escalation, variation and extra items, delayed handing over of site or drawings, non-payment of RA bills with interest, hindrance register entries as evidence.

Key points

Contract - agreement enforceable by law (Sec. 2(h), Indian Contract Act, 1872); needs offer, acceptance, consideration, free consent, lawful object, competent parties.
Item rate contract - payment by measured quantity × quoted rate; owner carries quantity risk; the Indian government default.
Percentage rate contract - bidders quote one percentage above/below the departmental Schedule of Rates; eliminates unbalanced bidding.
Lump sum contract - single fixed price against complete design; cost certainty for the owner, design-change risk for both.
Cost plus percentage - least incentive to economise; cost plus fluctuating fee or target cost corrects that.
EPC/turnkey - design plus construction with one agency; design risk on the contractor; NHAI and metro standard.
HAM - 40% of project cost paid by the authority during construction, 60% as annuity with interest after completion.
NIT - the invitation document: scope, estimated cost, EMD, time, eligibility, dates; publication on CPPP/GeM is mandatory under GFR, 2017.
Two-bid system - financial bid opened only for bidders who clear the technical bid; prevents price-led compromise on quality.
EMD - roughly 2% bid security against withdrawal; performance guarantee about 5%; retention/security deposit about 5% released after DLP (figures vary by department).
L1 vs QCBS - works go to the lowest evaluated responsive bid; consultancy to the best combined technical-and-price score.
Liquidated damages - pre-agreed compensation for delay under Sec. 74, typically 0.5-1% per week capped near 10%; must be compensatory, not penal.
Price escalation clause - adjusts payment using published labour, material, fuel and cement/steel indices, usually with an 85% factor and a base date.
Defect liability period - normally 12 months of free rectification after completion; security released only on its expiry.
Specification - defines quality and acceptance; prescriptive states the method, performance states the result.
IS 1200 - standard mode of measurement; the Measurement Book is the legal record of work done.
Arbitration and Conciliation Act, 1996 (amended 2015/2019/2021) - the main route for construction disputes, with statutory time limits on awards.
Priority of documents clause - decides which document prevails when drawings, specifications and BOQ disagree.

Formulas and examples

EMD = p_E × C_est, where p_E ≈ 0.02 (2%) and C_est = estimated cost put to tender (₹); slabs/ceilings per NIT
Performance security = p_P × C_contract (p_P ≈ 0.05); Retention per bill = p_R × value of that bill (p_R ≈ 0.05 up to a ceiling)
Liquidated damages LD = r_LD × C_contract × n, capped at L_max × C_contract (r_LD = rate per week/day, n = periods of delay)
Item-rate bill amount = Σ (Q_i × R_i), Q_i = measured quantity of item i (m, m², m³, kg, no.), R_i = accepted rate (₹ per unit)
Price adjustment (component-wise, CPWD/MoRTH form): V_x = 0.85 × (P_x/100) × R × (I_x − I_0)/I_0
V_x = escalation payable for component x (₹); P_x = that component's percentage of contract value; R = gross value of work done in the period (₹); I_0, I_x = index at base date and at the period's mid-point; 0.85 = the 15% risk retained by the contractor (factor and components vary by contract)
Cost plus percentage: payment = A × (1 + f), A = audited actual cost (₹), f = agreed fee fraction
Bid capacity (common PQ formula) = 2 × A × N − B; A = maximum value of construction work executed in any one year of the last five years (brought to current price level), N = number of years prescribed for completing the work being bid, B = value of existing commitments to be completed in the next N years

Example 1 - EMD, performance security and retention. Estimated cost put to tender ₹8.50 crore; contract awarded at ₹8.20 crore. EMD 2%, performance guarantee 5%, retention 5% of each bill.

EMD = 0.02 × 8,50,00,000 = ₹17,00,000 (on the estimate, as per NIT).
Performance guarantee = 0.05 × 8,20,00,000 = ₹41,00,000, as a bank guarantee before signing.
A first RA bill of ₹1.10 crore: retention = 0.05 × 1,10,00,000 = ₹5,50,000; net payable before taxes/advances = ₹1,04,50,000.

Example 2 - Item-rate bill and arithmetic correction.

Item	Quantity measured	Rate (₹)	Amount (₹)
Earthwork excavation	1,250 m³	210 /m³	2,62,500
PCC 1:4:8	85 m³	5,400 /m³	4,59,000
RCC M25	310 m³	7,800 /m³	24,18,000
Reinforcement Fe 500D	28,500 kg	82 /kg	23,37,000
Brickwork CM 1:6	420 m³	6,250 /m³	26,25,000
Total			81,01,500

If the bidder had written the RCC amount as ₹24,80,000 against a rate of ₹7,800/m³, the quoted unit rate prevails in evaluation: the amount is corrected to ₹24,18,000 and the bid total reduced by ₹62,000 before comparison.

Example 3 - Price escalation. Gross work done in a quarter R = ₹2.00 crore. Labour component P_L = 25%, cement P_C = 10%. Labour index rose from 220 to 242; cement index from 180 to 189.

Labour: V_L = 0.85 × 0.25 × 2,00,00,000 × (242 − 220)/220 = 0.85 × 0.25 × 2,00,00,000 × 0.10 = ₹4,25,000.
Cement: V_C = 0.85 × 0.10 × 2,00,00,000 × (189 − 180)/180 = 0.85 × 0.10 × 2,00,00,000 × 0.05 = ₹85,000.
Total escalation for the quarter = ₹5,10,000 (2.55% of the quarter's work).

Example 4 - Liquidated damages with a cap. Contract ₹5.00 crore, stipulated completion 18 months, actual 18 months + 10 weeks, EOT granted for 3 weeks. LD 0.5% of contract value per week, capped at 10%.

Chargeable delay = 10 − 3 = 7 weeks. LD = 0.005 × 5,00,00,000 × 7 = ₹17,50,000 (3.5%).
Cap = 0.10 × 5,00,00,000 = ₹50,00,000, so the full ₹17,50,000 is recoverable from the bills or security.

Example 5 - Lump sum versus cost plus. Scope estimated at ₹1.00 crore. Lump sum bid ₹1.08 crore; cost-plus offer at actual cost + 10% fee. Actual audited cost comes to ₹1.15 crore (scope grew).

Cost plus payment = 1,15,00,000 × 1.10 = ₹1,26,50,000.
Lump sum payment = ₹1,08,00,000 plus any valued variation; the owner's exposure is ₹18.5 lakh lower, but only because the scope growth was within the lump sum definition — had it been a genuine variation, it would have been paid for separately at BOQ/SOR rates.

Basis	Item rate	Lump sum	Cost plus	EPC/turnkey
Price fixed?	Rates fixed, quantity variable	Yes	No	Yes (for defined output)
Design completeness needed	Moderate	Complete	Minimal	Concept only
Owner's cost risk	Quantity variation	Low	High	Low
Contractor's risk	Rates and productivity	Quantities and rates	Very low	Design, quantity and rates
Best used for	Government building and road works	Fully designed buildings	Emergency and repair work	Highways, metros, plants

Where it is used

Government works departments - CPWD, state PWDs, irrigation, municipal corporations and PSUs: NIT drafting, tender scrutiny sheets, MB recording, RA bills, deviation statements, final bills and audit replies (the core work of a junior/assistant engineer).
Infrastructure authorities - NHAI, NHIDCL, railways/RVNL, metro corporations, port trusts: EPC, HAM and concession agreements, independent engineer certification, price adjustment and claims.
Private contractors and developers - L&T, Tata Projects, Shapoorji Pallonji, AFCONS, Dilip Buildcon: bid/tender cells preparing rate analysis and bid capacity statements, contracts and claims departments, sub-contract back-to-back agreements.
Consultancy and PMC - tender document preparation, specification writing, bid evaluation reports, contract administration for clients.
Quantity surveying, billing and planning roles - BOQ control, variation valuation, escalation computation in Excel/ERP (SAP, Candy, Primavera-linked billing).
Arbitration and claims practice - construction law firms, arbitral tribunals and the dispute boards of large projects; hindrance registers, delay analysis and extension-of-time claims.

Interview questions

Q: What makes a construction agreement a valid contract? A: Offer and acceptance, lawful consideration, competent parties, free consent, lawful object, certainty of terms and enforceability under the Indian Contract Act, 1872 — a tender becomes a contract only when acceptance is communicated.
Q: When would you choose an item-rate contract over a lump sum? A: When quantities cannot be fixed accurately at tender stage (excavation, foundations, repair work); a lump sum needs fully frozen drawings and specifications, otherwise variation claims multiply.
Q: Why is the percentage rate contract used in government work? A: All bidders price the same departmental Schedule of Rates, so bids differ by a single percentage — this removes arithmetic errors and unbalanced bidding, and simplifies comparison.
Q: What is the difference between EMD, performance security and retention money? A: EMD is bid security against withdrawal before award; performance security (usually a bank guarantee) secures performance of the contract; retention is deducted from running bills and released after the defect liability period.
Q: Why a two-bid system? A: Technical bids are evaluated first and financial bids of only qualified bidders are opened, so price cannot influence the technical judgement and unqualified low bids are eliminated.
Q: Is L1 always awarded the work? A: No — the award goes to the lowest *evaluated responsive* bid; a bid that is non-responsive, unqualified or abnormally low (requiring additional security or rejected after rate justification) can be set aside, and consultancy uses QCBS.
Q: Difference between liquidated damages and a penalty? A: Liquidated damages are a genuine pre-estimate of loss and recoverable under Sec. 74 as reasonable compensation; a sum that is purely punitive is scaled down by courts to actual reasonable compensation.
Q: How does a price escalation clause work? A: Each cost component (labour, cement, steel, bitumen, fuel) is given a percentage of the contract value and adjusted by the change in a published index from the base date, usually multiplied by 0.85 so the contractor retains part of the risk.
Q: Prescriptive versus performance specification? A: Prescriptive states materials and method and leaves the result risk with the owner; performance states the required end result (strength, roughness, density) and lets the contractor choose the method, carrying the result risk.
Q: Which documents govern if the drawing, BOQ and specification conflict? A: The priority-of-documents clause in the contract; typically the agreement and special conditions override general conditions, with specifications prevailing over drawings for quality and drawings over BOQ for dimensions.
Q: How is the rate for an extra item not in the BOQ fixed? A: Under the deviation clause — derived from BOQ rates for similar items, then the departmental Schedule of Rates with the tender percentage, and only failing both, by fresh market rate analysis approved by the competent authority.
Q: What is the defect liability period and how does it differ from a maintenance contract? A: DLP (typically 12 months) obliges the contractor to rectify defects free of cost from the same contract; a maintenance or O&M contract is a separately paid obligation to operate and maintain the asset.

Common mistakes

Treating a tender as a contract — there is no contract until acceptance is communicated and, where stipulated, the agreement is signed and security furnished.
Writing "lowest tender must be accepted" — the correct answer is the lowest *evaluated responsive* bid from a qualified bidder.
Confusing EMD with security deposit/performance guarantee, or quoting a single percentage as universal when departments differ (always cite the NIT).
Applying escalation to the whole bill instead of component-wise with the 0.85 factor and the correct base index, or escalating work done beyond the stipulated period without checking the clause.
Mixing up prescriptive and performance specifications, and writing specifications that repeat the drawing instead of stating materials, workmanship, tests and tolerances.
Omitting the measurement and payment clause (and the IS 1200 mode) from a detailed specification, which makes the item unbillable without dispute.
Arithmetic slips in bill and LD computations — wrong units (m³ priced as m²), forgetting the LD cap, or deducting LD on the estimated instead of the contract value.