Question 1 of 6: Estimating and Bidding — RS Means unit costs and crew-based duration
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Notes on this paper
National Examinations — May 2014 — 07-Str-B2 Management of Construction. Three hours, closed book; candidates may use one of the two approved calculators (Casio or Sharp). The paper prints six questions of equal value (20 marks each) and states that any five questions constitute a complete paper, only the first five appearing in the answer book being marked. Candidates are urged to submit a clear statement of any interpretive assumptions with their answers. All six questions are worked below, because this set is intended as a study resource rather than as a single exam sitting.
Reference texts: RSMeans, Building Construction Cost Data — the "How to Use the Cost Data" front matter, which defines daily output, labour-hours, bare costs and the Total Incl. O&P column used in Question 1; Halpin, D.W. & Senior, B.A., Construction Management (4th ed., Wiley) — unit-price estimating, crew balancing, labour relations and construction safety; Hegazy, T., Computer-Based Construction Project Management (Prentice Hall) — precedence networks with SS/FS/FF relationships and lags, which is exactly the notation of Question 2; Hendrickson, C. & Au, T., Project Management for Construction (2nd ed., Carnegie Mellon) — scheduling and cost control; Sullivan, W.G., Wicks, E.M. & Koelling, C.P., Engineering Economy (17th ed., Pearson) — present-worth analysis and the maximum-justified-investment problem of Question 4; Canadian Construction Documents Committee, CCDC 2 — Stipulated Price Contract (2020), General Conditions 6.5 (delays) and 6.6 (claims for a change in Contract Price); Goldsmith, I. & Heintzman, T.G., Goldsmith on Canadian Building Contracts (5th ed., Thomson Reuters) — delay and notice law in Canada; AACE International, Recommended Practice 29R-03: Forensic Schedule Analysis — the but-for and windows methods named in Question 5; British Columbia Labour Relations Code, RSBC 1996 c. 244 — certification, bargaining units and the construction-industry provisions behind Question 3; WorkSafeBC, Occupational Health and Safety Regulation (Parts 4, 8, 11, 18 and 20) and the BC Workers Compensation Act — the prime-contractor duty and the traffic-control, fall-protection and hazardous-substance rules behind Question 6.
Check — two readings taken from the printed page. The RS Means extract in Question 1 prints two cells as question marks; both are recovered below from the crew table, and the recovered labour-hour figure is checked against the printed $27 labour column before it is used. Two arrows leave the right-hand edge of activity D and turn vertically to reach E and C; they are read here as ordinary finish-to-start links, which is the only reading consistent with the drawing and with the fact that every unlabelled arrow on the sheet carries no lag.
Question 1: Estimating and Bidding — RS Means unit costs and crew-based duration (20 marks)
Find. (a) The two cells printed as question marks — the labour-hours per square metre and the Total Incl. O&P unit price; (b) the construction cost and the calendar duration of 1250 m2 of the same work executed by a five-worker local crew paid at local bare rates.
Approach. Recover the productivity constant that ties the RS Means line together — labour-hours per unit — from the crew's daily labour-hours and its daily output, check it against the printed labour column, use it to rebuild the Total Incl. O&P price, and then carry the same constant across to the new job, where only the crew size and the wage rates have changed.
Recover the missing labour-hours per unit. The RS Means labour-hours column reports the crew hours consumed per unit of finished work, which is simply the crew's daily labour-hour content divided by what the crew produces in that day:
$$H_u=\frac{H_c}{Q_d}=\frac{16\ \text{L.H./day}}{13.94\ \text{m}^2\text{/day}}=\boxed{1.148\ \text{L.H./m}^2}$$
The crew table confirms the numerator directly: it is footed “16 L.H., Daily Totals”, which is one tile layer plus one helper, each for an eight-hour shift.
Check the recovered value against a printed cell. A productivity figure recovered from one part of the table must reproduce the rest of it. Multiplying the labour-hours per unit by the bare cost per labour-hour must return the printed bare labour column:
$$c_L=H_u\,r_b=1.1478\times 23.55=\$27.03\ \text{/m}^2\approx\$27\ \checkmark$$
and the printed bare total agrees as well, since $48.50+27.00=\$75.50$ per square metre. The recovered 1.148 L.H./m2 is therefore the number RS Means used.
Rebuild the Total Incl. O&P unit price. RS Means loads the two cost components differently. Bare material is marked up 10 % for handling and profit, while labour is carried at the crew's own incl.-O&P rate, which already contains payroll burden, workers' compensation, overhead and profit. Taking the two in turn,
$$c_{m,o}=1.10\,c_m=1.10\times 48.50=\$53.35\ \text{/m}^2$$
$$c_{L,o}=H_u\,r_o=1.1478\times 34.83=\$39.98\ \text{/m}^2$$
There is no equipment in this line, so the two components are the whole price:
$$\text{Total Incl. O\&P}=53.35+39.98=\boxed{\$93.33\ \text{/m}^2}$$
which RS Means would print as roughly $93.50 after its own rounding.
Carry the productivity constant to the new job. Labour-hours per unit is a property of the work and the method, not of how many workers are sent to do it. Enlarging the crew therefore multiplies the daily output but leaves $H_u$ alone. The total labour content of the new job is
$$W=Q\,H_u=1250\times 1.1478=1434.7\ \text{L.H.}$$
Size the local crew and get the duration. Three tile layers and two helpers are five workers, each working an eight-hour shift, so
$$H_c'=5\times 8=40\ \text{L.H./day}$$
$$T=\frac{W}{H_c'}=\frac{1434.7}{40}=35.87\ \text{days}\ \Rightarrow\ \boxed{36\ \text{working days}}$$
The same answer follows from the output side, which is a useful independent check: the crew is 2.5 times the size of D-7, so its daily output is $13.94\times 2.5=34.85$ m2/day, and $1250/34.85=35.87$ days.
Price the local labour. The $23.55 and $34.83 rates belong to the RS Means national crew and must not be used here; the question supplies the local bare wages instead. The mixed crew costs
$$C_d=(3\times 30+2\times 23)\times 8=(90+46)\times 8=\$1{,}088\ \text{/day}$$
which is an average bare rate of $1088/40=\$27.20$ per labour-hour — noticeably richer than the RS Means $23.55 because the local crew is weighted three-to-two toward journeymen rather than one-to-one. The labour bill is then
$$C_L=W\times 27.20=1434.7\times 27.20=\$39{,}024$$
Add the material and total the estimate. Material is unaffected by who installs it, so it is carried at the RS Means bare rate:
$$C_M=Q\,c_m=1250\times 48.50=\$60{,}625$$
$$C=C_M+C_L=60{,}625+39{,}024=\boxed{\$99{,}649\ \text{bare construction cost}}$$
If the estimate is to be reported on the same basis as the Total Incl. O&P column, the material is marked up 10 % and the labour is loaded by the factor the crew table itself implies, $34.83/23.55=1.479$, giving $\$66{,}688+\$57{,}716=\$124{,}404$. That loaded figure, not the bare one, is what would go into a bid.
