BQA Grade 9 cheat sheet

Open tendering invites any qualified bidder publicly; selective tendering invites only pre-qualified firms; negotiated tendering awards without competition, usually for specialist or urgent work.

A tender is an offer, not an acceptance; a binding contract forms only when the client issues an unconditional acceptance, and a conditional acceptance is a counter-offer.

A bid bond (typically 5-10% of tender price) protects the client if the successful bidder refuses to sign; a performance bond (typically 10%) covers post-award default.

Prequalification screens bidders on financial standing, technical capability, and safety record before tender documents are issued.

Addenda issued during the tender period become part of the tender documents and must be acknowledged by bidders; late addenda may justify an extension to the closing date.

Two-envelope tendering separates technical proposals from priced offers so technical evaluation is not influenced by price.

A tender clarification does not change scope or price; a material change after closing may require re-tendering to preserve fairness.

Best value evaluation scores price and non-price criteria (quality, programme, safety) using stated weightings published in the tender documents.

Letters of intent may create binding obligations if they commit payment for defined work; they are not a substitute for a signed contract.

A variation is a change to scope, quality, quantity, or timing authorised in writing by the contract administrator; oral instructions should be confirmed in writing.

An extension of time adjusts the completion date for excusable delay; it does not automatically entitle the contractor to loss and expense.

Liquidated damages are a pre-agreed genuine estimate of loss per day of culpable delay; they are unenforceable if they are a penalty.

Interim payments are certified at stated intervals; the final certificate follows the defects liability period and releases retention.

Retention is typically 5% deducted from payments, often reduced to 2.5% on practical completion, with the balance released after the defects period.

Practical completion marks the date the works are fit for purpose and handed over; it starts the defects liability period and triggers release of half the retention.

A site instruction records a directive on site; if it constitutes a variation it must be valued and certified through the change procedure.

Substantial completion vs final completion: the former transfers risk and possession, the latter closes all accounts and releases final retention.

Unit rate build-up: rate = labour + material + plant + subcontract cost + overheads + profit, divided by the measured quantity.

Labour cost per unit = (daily wage x crew size) / daily output, or wage divided by output per hour.

All-in labour rate includes base wage plus on-costs such as insurance, holiday pay, and supervision; ignore only if the client requires bare rates.

Preliminaries are site-wide costs (site staff, temporary works, insurance, welfare) that are not attributable to a measured item and are often priced as a lump sum.

Contingency is an allowance for identified but unquantified risk; it is not a substitute for accurate measurement.

Cost planning stages: order-of-magnitude, elemental, and detailed; accuracy improves as design information matures.

Escalation adjusts estimates for inflation between the estimating date and the construction period using a stated index.

Cash flow forecasting spreads cost over the programme; it differs from the priced bill, which is not time-distributed.

Pricing errors: an arithmetically unbalanced bid loads early items for cash flow; it is legitimate only if not misleading.

Critical path is the longest duration path through the network; it determines the minimum project duration and has zero total float.

Total float = latest finish minus earliest finish for an activity; free float is the delay possible without affecting the next activity's early start.

A Gantt chart shows activities against time but does not by itself show logical dependencies; network diagrams show logic.

A milestone has zero duration and marks a key event or decision point.

Crashing shortens duration by adding resources to critical activities; fast-tracking overlaps activities that would normally be sequential.

Resource levelling smooths peaks within float; resource smoothing may extend duration if float is insufficient.

Lag is a mandatory delay between finish and start of linked activities; lead is a negative lag allowing overlap.

Progress S-curve plots cumulative cost or work against time and is used to compare planned versus actual performance.

Programme logic must reflect construction sequence; an activity with no predecessor is a dangling activity and an error.

Concrete strength is specified by characteristic cube strength at 28 days; curing maintains moisture and temperature for hydration.

Formwork must resist fresh concrete pressure, which increases with pour height and rate; strike times depend on strength gain, not fixed hours.

Reinforcement cover protects steel from corrosion and provides fire resistance; cover is set by spacers, not by bar diameter alone.

Excavation support: battered slopes suit stable ground; shoring or sheet piles are needed where space or ground conditions prevent battering.

Dewatering lowers the water table to keep excavations dry; it must consider settlement risk to adjacent structures.

Brickwork bond patterns (stretcher, English, Flemish) distribute loads and tie the wall; mortar joint thickness affects compressive strength.

Structural steel connections are bolted (friction or bearing) or welded; bolt torque and weld inspection are quality-critical.

Foundations: strip footings suit continuous load-bearing walls; pad footings suit isolated columns; rafts spread load over weak ground.

Roof pitch and covering selection are governed by weathertightness; minimum pitch depends on the covering material and lap.

Hierarchy of control: eliminate, substitute, engineering controls, administrative controls, then PPE as last resort.

Risk = likelihood x severity; residual risk is what remains after controls are applied and must be recorded.

A method statement describes the safe sequence of work; a risk assessment identifies hazards and controls; a permit-to-work authorises high-risk tasks.

Working at height: fall protection is required above 2 m in many jurisdictions; guardrails, nets, and harnesses follow the hierarchy.

Excavations deeper than 1.2-1.5 m generally require shoring or battering, and must be inspected by a competent person before entry.

Silica dust, asbestos, and noise are common occupational health hazards; controls include wet methods, enclosure, and hearing protection.

Environmental controls: silt traps and settlement ponds prevent sediment entering watercourses; dust suppression uses water sprays.

Waste hierarchy: prevent, reuse, recycle, recover, dispose; disposal is the least preferred option.

Incident reporting: near misses are recorded to prevent recurrence; serious incidents trigger statutory notification and investigation.

Conflict of interest must be disclosed in writing as soon as it is known; failure to disclose is a breach of professional duty.

Confidentiality: client information is not disclosed without consent except where law or safety requires it.

Bribery and facilitation payments are prohibited; gifts and hospitality must be declared and recorded per policy.

Competence: professionals must work only within their competence and seek specialist advice where needed.

Integrity in tendering: collusion (bid rigging, cover pricing) is unlawful and a serious professional misconduct.

Accuracy in certification: certifying work not executed or overstating progress is fraudulent and grounds for dismissal and prosecution.

Whistleblowing: concerns about unsafe or unlawful practice should be raised through internal channels first, then regulators if unresolved.

Fair dealing: subcontractors and suppliers must be treated consistently with the terms offered to the main contractor; payment terms should be honoured.