Measurement Checklists

Measurement Checklists KCTang Mon, 23/03/2020 - 18:12

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Note

23 Mar 2020: Numeric numbering system adopted. Punctuation standardised.

13 Mar 2020: Contents expanded.

3 Aug 2019: HKSMM4 Revised 2018 incorporated.

27 Jul 2019: Split to its own page and revised.

23 Dec 2014: Moved from wiki.

Clarify which Method of Measurement

  1. The Method of Measurement (more properly “rules”) to be used or which has been used should be clarified during the briefing session upon commencement of taking-off. 
    採用的標準工程量計算規則在開始計量的交底會確定。
  2. For pre-contract cost estimates, the Method of Measurement will be determined by the Consultants, and the quantities are usually approximate and relative items are grouped together to save time.
  3. For Pricing Schedules with quantities provided by the Consultants, the Method of Measurement should be stated.
  4. For new works, the Method of Measurement will be prescribed as to follow the Hong Kong Standard Method of Measurement of Building Works – Fourth Edition 2005 (“HKSMM4”) or Fourth Edition Revised 2018 ("HKSMM4R") published by The Hong Kong Institute of Surveyors.
  5. For Government term maintenance contracts, they use the Schedule of Rates for Term Contracts for Building Works (ttp://www.archsd.gov.hk/en/publications-publicity/bill-of-quantities,-method-…), which prescribe the Method of Measurement.
  6. The standard methods of measurement describe what should be measured and what can be deemed to be included in the rates and prices and need not be measured.
  7. For Pricing Schedules with quantities to be inserted by the Tenderers, the Method of Measurement may be prescribed by the Consultants but usually it is left to the Tenderers.
  8. The Tenderers may follow the standard Method of Measurement or may simplify or deviate.
  9. In any case, the method used by the Tenderers in the Pricing Schedule should be used for pricing variations and remeasured provisional quantities.

Read Method of Measurement 閱讀標準工程量計算規則

  1. Inexperienced Takers-off should read the relevant sections of the prescribed Method of Measurement before taking-off.
    生手計量員應在計量前閱讀瞭解計算規則。
  2. Experienced Takers-off should review the relevant sections of the prescribed Method of Measurement from time to time during the course of taking-off.
    熟手計量員應不時重溫計算規則。
  3. Upon completion of taking-off, all Takers-off should take a final review of the prescribed Method of Measurement to ensure that there are no missing items to be measured.
    計量完畢,全部計量員應翻閱計算規則,確保沒有錯漏。

Pay extra attention to how to treat 特別要注意如何處理的

  1. Wastage (not measured).
    損耗
  2. Gross or net measurement.
    毛或淨量
  3. Deductions for openings (small voids or openings not deducted, such as those not exceeding 0.50 m2 or 1.00 m2 or 0.50 m3 depending on the type of work).
    扣除孔洞
  4. Laps and intersections.
    搭接、交叉
  5. Working space for excavation (0.25 m or 0.60 m depending on the height of formwork below ground).
    工作面
  6. Slopes of excavated spaces (designed or restricted excavation profiles).
    放坡
  7. Staging or ranging where items can be measured together or separately (excavation depth below ground in successive stages of 1.50 m, soffit formwork and ceiling finishes heights above floor not exceeding 3.50 m high, then in 1.50 m stages, etc.).
    步距
  8. Sloping work (from horizontal) / slanting work (from vertical).
    斜坡、傾斜
  9. Circular work (usually measured separately).
    弧形
  10. Extra over items (principal items overlapping with the extra over items not deducted in the quantities, but to be considered in the unit rates, e.g. pipe bends, tees, etc.).
    補差計量
  11. Tenderers not strictly following any standard Method of Measurement may follow the above treatment as common practice.

Measure net quantities

  1. Measure all work net as fixed in position, unless otherwise stated.
  2. This is a very important principle.
  3. If there is no prescribed Method of Measurement, at least state that “all work is to be measured its net quantity as fixed in position with no allowance for wastage and, in case of work measured superficially, for laps, unless otherwise stated”.
  4. Work which are “superficial” (as compared to “lineal” or “cubic”) and have laps not to be measured are wire mesh, waterproof layers, pitched roof tiling, etc.
  5. Work which are lineal and have laps to be measured are reinforcement bars, door frames, skirtings, etc.

Deduct voids

  1. Voids (openings and wants) smaller than the sizes specified in the SMM are not to be deducted.
  2. However, this refers to voids detached from the boundaries of the space measured.
  3. Voids caused by projections from the boundary of the space measured are always deducted:

Costs held to be included in items (HKSMM4 and HKSMM4R)

  1. Labour and all costs in connection therewith
  2. Materials, goods and all costs in connection therewith (e.g. conveyance, delivery, unloading, storing, returning packings, handling, hoisting and lowering)
  3. Fitting and fixing materials and goods in positions
  4. Use of plant
  5. All cutting and waste
  6. Establishment charges, overhead charges and profit.

Units of measurement (HKSMM4 and HKSMM4R)

  1. Items given by weight - kilograms
  2. Items given cube - cubic metres
  3. Items given super - square metres
  4. Items given run - linear metres
  5. Items enumerated - number of sets, as applicable
  6. Items given by time - Days or Hours, with definitions stated
  7. Dimensions used in calculations - rounded off to the nearest 10 mm.

Units of billing (HKSMM4 and HKSMM4R)

  1. Billing BQ:
    • Rounded to the nearest whole unit
    • Subject to a minimum of 1 if more than 0
  2. Billing variations and remeasurement:
    • Rounded to the nearest 0.1 for m, m2, m3
    • Rounded to the nearst 1 for kg
    • Applicable to omissions or additions
    • Quantity less than 1 but billed as 1 in the original contract to be omitted as 1 if the quantity is not done.

Order of dimensions in BQ or dimension sheets

  • Generally in the sequence of length, width and height.

Ranges

  1. When a range of widths, heights, depths, etc. is given in the item description in a Pricing Schedule, “A – B” usually means “exceeding A but not exceeding B”.
  2. A - B = exceeding A but not exceeding B = "> A but <= B".

Pipe and tubing

  1. Pipe size: to be described by nominal sizes (HKSMM4 and HKSMM4R) vs by internal diameter (HKSMM3).
  2. HKSMM3 pipe size groups for the purposes of painting (all measured run):
    • Small pipes = pipes <= 55 mm diameters
    • Large pipes = pipes 55 - 110 mm diameters
    • Pipe size stated = pipes > 110 mm diameters.
  3. HKSMM4 pipe size groups for the purposes of painting (all measured run):
    • pipes <= 50 mm diameters
    • pipes 50 - 100 mm diameters
    • pipes > 110 mm diameters, pipe size stated.
  4. HKSMM4R pipe size groups for the purposes of painting:
    • pipes <= 300 mm girth (measured run)
    • pipes > 300 mm girth (measured super).

Circular work

  1. HKSMM3 only:
    • Small radius = 0 - 300 mm radius
    • Medium radius = 300 mm - 1.50 m radius
    • Large radius = radius > 1.50 m.
  2. HKSMM4 and HKSMM4R:
    • No grouping by radius.

Prime Cost Rates (P.C. Rates)

  1. Where a prime cost rate (P.C. rate) is included for a component in the description of an item in the Bills of Quantities, the prime cost rate is either (a) for the material cost of that component delivered to site only and the Contractor shall allow in addition for all waste, fixing, all ancillary materials required for fixing such as mortar for bedding and jointing and all other similar items of a like nature, and for profits and overheads, or (b) for the cost of supply and installation or application of the component (such as specialist suspended ceilings or finishes) as charged by a domestic sub-contractor, and the Contractor shall allow for his own profits and overheads.
  2. In the settlement of the Final Account, the rate for the item will be adjusted by the net difference between the prime cost rate and the actual unit cost and will be applied to the nett quantity of the component measured as fixed, installed or applied in position, exclusive of wastage.

Provisional Sum

  1. A sum provided for work or for costs which cannot be entirely foreseen, defined or detailed at the time the tendering documents are issued (HKSMM4 and HKSMM4R).
  2. In the settlement of the Final Account, the provisional sum will be omitted from, and the actual expenditure added to the Contract Sum.

Prime Cost Sum

  1. A sum provided for work or for services to be executed by a Nominated Sub-Contractor or for materials or goods to be obtained from a Nominated Supplier. Such sum shall be deemed to be exclusive of any profit or attendance required by the Contractor and provision shall be made for the addition thereof (HKSMM4 and HKSMM4R).
  2. In the settlement of the Final Account, the Prime Cost Sum will be omitted from, and the actual expenditure added to the Contract Sum.
  3. The Contractor’s profit is to be allowed as a percentage of the Prime Cost Sum. The same percentage will be applied to the final expenditure of the Prime Cost Sum in the settlement of the Final Account.
  4. The Contractor’s attendance is to be allowed as a lump sum not to be adjusted in the settlement of the Final Account, but if the Prime Cost Sum is not expended at all, then the lump sum will be omitted.

Work to be specifically described as such (HKSMM4 and HKSMM4R)

  1. Work under reservoir, river or sea water
  2. Work in compressed air
  3. Work outside the curtilage of the Site
  4. Work in existing building
  5. Temporary works.

Preliminaries

  1. Items should be included in the Preliminaries Bill to inform the tenderers and to specify requirements to enable them to price for the costs.
  2. HKSMM4R:
    • Preliminary Particulars
      • Employer and consultants
      • Description of the Works
      • Site and inspection
      • Division of the Works into sections
    • Conditions of Contract
      • Forms of Contract and Sub-Contract
      • Particulars to be inserted in Appendix to Schedule of Conditions
    • General matters
      • Working hours, rates of wages, etc.
      • Plant, tools, scaffolding, site offices, sheds, etc.
      • Statutory obligations
      • Safety supervision plan and safety precautions
      • Construction Levy
      • Pneumoconiosis and Mesothelioma Levies
      • Setting out
      • Contractor's site management team
      • Protection of public and adjacent property
      • Sub-letting
      • Persons or specialist contractors engaged by the Employer
      • Injury to persons and damage to property
      • Insurances (Contractors' all risks, third party liability, employees' compensation, construction plant, materials off site)
      • Provisional and Prime Cost Sums
      • Conditions of payment
      • Surety or bond
      • Watching
      • Protection
      • Antiquities, etc.
      • Variations and method of measuring and valuing
      • Samples
      • Testing of materials
      • Removal of water
      • Temporary water
      • Temporary lighting and power
      • Attendance
      • Hoardings, etc.
      • Works by public authorities
      • Temporary roads
      • Drying the building
      • Removal of rubbish
      • Defects after completion
      • Co-ordination of services
      • Building information modelling.

Piling

  1. Commencement level / commencing level:
    • Identify the commencement level of piling - existing ground level, level after general site levelling or bulk site formation, or bottom level of footing or basement excavation.
    • State the commencement level in the BQ - the commencement level may not always be the formation level as stipulated by the SMM.
  2. Usual items:
    • Mobilization and demobilization.
    • Trial piles.
    • Preformed portion (whole piles, linings only, driven or placed):
      • Supplying
      • Reinforcing if not described to be included in the supply
      • Driving
      • Dollying
      • Cutting
      • Withdrawal.
    • Cast in-situ portion (whole piles, fillings only, pre-boring):
      • Boring
      • Reinforcing
      • Casting
      • Cutting.
    • Heads, shoes.
    • Testing:
      • Before piling
      • During piling
      • After piling.
  3. Usual units:
    • Area for steel sheet piles or contiguous piles - Measure the area in plane (not developed) elevation along the centre line of steel sheet piles
    • Length for piles in isolated pieces
    • Length or number for extra over items or isolated items.
  4. Supplying preformed portion (including handling, transporting and pitching) :
    • Describe clearly the method of measurement of the area or length or number of supply
    • HKSMM4 or HKSMM4R does not specifically state how the length is to be measured to give the supply quantity of steel sheet piling or precast concrete piles
    • It only requires the "design length" to be stated, but does not say that this is the length to be measured for supply quantity
    • "design length" is defined by HKSMM4 or HKSMM4R as the length specifically required by the designer. However, the designer often does not specifically specify the design length. He usually only specifies the length below cut-off. It is therefore essential to define design length or describe the supply length measured, e.g. as driven length or length below cut-off, with or without allowance for extra length above the top
    • The supply length can in some cases be shorter than the driven length if the top is required to be driven below ground (dollying).
  5. Driving piles:
    • Measure from commencement level of driving to bottom level of driven pile.
  6. Corner piles, junction piles and other special piles to steel sheet piles:
    • Measure as extra over the supplying and driving items "respectively" of the steel steel piling into which they occur
    • Since the supply area may not be the same as the driven area, therefore, "respectively" should mean "separately" for supply items and driving items, or the description of the extra over items should be clear enough.

Excavation

  1. Commencement level / commencing level:
    • Identify and state the commencement level of excavation
    • Usually, the commencement level would be the existing ground level or the formation level whichever is the lower at a particular point.
    • Usually, "formation level" means the underside of the hardcore bed or blinding level of the lowest floor slab or external paving
    • Usually for a site to be "cut", i.e. formation level lower than existing ground level, the site would be formed to the formation level first, and foundations excavation would commence from the formation level
    • Usually for a site to be "filled", i.e. formation level higher than existing ground level, foundations excavation would commence from the existing ground level, backfilled and filled up to the formation level
    • "Usually" means that the definitions for specific projects should be defined and described in the BQ.
  2. Working space:
    • 0.25 m from the face of concrete requiring formwork where the formwork does not exceed 0.60 m in height
    • 0.60 m from the concrete requiring formwork where the formwork exceeds 0.60 m in height AND the bottom of the formwork exceeds 0.60 m below the commencement level of excavation
    • 0.60 m from the finished face of work below ground level where externally applied dampproof coverings or protection walls are required or where the method of construction requires workmen to operate from the outside (NOTE, "ground level" should mean that when the workmen go down to do the coverings or protection walls but this should be clarified in the BQ).
  3. Usual units:
    • Number for post holes not exceeding 0.30 m3
    • Length for trench excavation
    • Area for surface excavation not exceeding 0.20 m in average depth (HKSMM4 only. Volume measured as HKSMM4R)
    • Area for backfilling or filling not exceeding 0.30 m in total depth (HKSMM4 only. Volume measured as HKSMM4R)
    • Volume for other excavations, filling and disposal.
  4. Balancing:
    • Excavation = surplus disposal + backfilling
    • Import fill = filling to make up level - surplus disposal from excavation.

Concrete works

Drainage

  1. HKSMM4 only - When classifying drainage trench excavations by the total depth in stages of 1.50 m, with the average depth stated in multiples of 0.25 m, instead of taking the maximum total depth at the one end of the trench and measuring the whole length into that deepest stage, the length of the trench should be divided into different sections according to the total depth stages and the average depth taken for the different sections
  2. HKSMM4R only - Drainage trench excavations are classified by average depth only of each trench in stages of 0.25 m. Total depths no longer required.

Finishes and roofing

  1. Related items should be measured as a composite items before billing to ensure consistency in quantities. e.g. plaster and paint; tiling and screed; roofing tile, waterproof layer, insulation layer, screed, etc.
  2. Adjustments to be made for differences, e.g. bands, borders, channels, curbs, etc.

Swimming pool measurement checklist

  1. Excavation:
    • Excavation to reduce levels
    • Excavation for swimming pool
    • Backfilling
    • Disposal.
  2. Concrete:
    • Concrete blinding layer
    • Waterproof reinforced concrete in sides and bottom
    • Waterproof reinforced concrete angle fillet including formwork
    • Housing for scum channel.
  3. Formwork:
    • Formwork to sides of swimming pool
    • Formwork to soffit of suspended swimming pool
    • Opening for view panel.
  4. Reinforcement:
    • Steel bar reinforcement, stirrups, binders, etc.
  5. Waterproofing:
    • Waterproof membrane on sides and bottom of swimming pool.
  6. Finishes:
    • Waterproof cement and sand rendering on sides and bottom of swimming pool and behind scum channel
    • Tiling and waterproof screed on sides and bottom of swimming pool
    • Scum channel in tile
    • Steps in tile.
  7. Steel and metal works:
    • Cat ladder or step iron.
  8. Pipework:
    • Puddle flange connector
    • Water supply pipes
    • Water supply outlets
    • Drain pipes
    • Drain outlets.
  9. E&M works:
    • Filtration system and boiler.

Water tank measurement checklist

  1. Concrete:
    • Waterproof reinforced concrete
    • Waterproof reinforced concrete angle fillet including formwork
    • Reinforced concrete plinth.
  2. Formwork:
    • Formwork to sides and internal soffit of water tank
    • Left-in formwork to external soffit of water tank
    • Left-in formwork to form gap between walls
    • Formwork to concrete plinth
    • Boxing to form openings.
  3. Reinforcement:
    • Steel bar reinforcement, stirrups, binders, etc.
  4. Waterproofing:
    • Waterproof membrane/coating on top
    • Waterproof membrane/coating on internal sides and bottom.
  5. Finishes:
    • Waterproof cement and sand rendering to internal sides and bottom of non-potable water tank
    • Tiling and waterproof screed on internal sides and bottom of potable water tank
    • Finishes to top and external sides.
  6. Steel and metal works:
    • Cat ladder or step iron (inside & outside)
    • Trap door or cover.
  7. Pipework:
    • Puddle flange connector
    • Water supply pipe
    • Drain pipe
    • Overflow pipe
    • Air vent
    • Ball float valve.

Door measurement checklist

  1. Doors and frames:
    • Door leaf
    • Vision panel
    • Louvred panel
    • Door frame including bedding and pointing frames
    • Intumescent strip around fire rated doors
    • Architrave
    • Ground behind door frame.
  2. Ironmongery.
  3. Sundry metalwork:
    • Holdfast to door frame in brick and block wall
    • Anchor bolt to door frame in concrete wall
    • Floor dowels.
  4. Painting:
    • Painting to door leaf, door frame, architrave and ground.
  5. Sundry concrete:
    • Lintol
    • Wire mesh for lintol.

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