Quantification and Costing of Construction Works Flashcards
What is measurement?
The transformation of drawn information into descriptions and quantities, undertaken to value, cost and price construction work.
What are the different methods of measurement for a Cost Plan?
- Functional unit
- Floor area
- Elemental
- Approximate quantities
- Bill of quantities
What is the most commonly used standard of measurement?
NRM, IPMS.
What are the benefits of having a standard method of measurement?
- Provide structure for information
- Defines unit of measurement for different items, e.g. m, m2, m3, t
- Provides rules as to what is included within each item
- Defines terms used to avoid disputes
- Allows familiarity to development so measurement becomes quicker and easier
- Provides clear system of structuring other project information
What is SMM7?
Standard Methods of Measurement, superseded by NRM2
What is NRM1?
NRM1: Order of Cost Estimating and Cost Planning for Capital Building Works
NRM1 is a best practice guidance note offering guidance on the preparation of:
- Order of cost estimates
- Elemental cost models
- Cost plans
- Cost analyses
- Benchmark analyses
- Capturing historical cost data for order of cost estimates and elemental cost plans
- How to describe quantifying non-measurable items such as prelims, OH&P, fees, risk, inflation
How is NRM1 structured?
Part 1 - context and definitions
Part 2 - how to prepare an order of cost estimate
Part 3 -how to prepare an elemental cost plan
Part 4 - tabulated rules of measurement for preparing cost plans
What is NRM2?
NRM2: Detailed measurement for building works
NRM2 provides a set of detailed measurement rules for preparing a BoQ or schedules of rates for the purpose of obtaining a tender price.
It also deals with quantification of non-measurable work items, Contractor designed works and risks.
NRM2 also offers guidance on the content, structure and format of bills of quantities.
How is NRM2 structured?
Part 1: Context and definitions
Part 2: Rules for detailed measurement of building works
Part 3: Tabulated rules of measurement for building works
What is in appendix A of NRM2?
Guidance on the preparation of BoQ
What is in Appendix A of NRM1?
Core definitions of GIA
What is in Appendix B of NRM1?
Commonly used functional units and functional units of measurement
What is in Appendix C of NRM1?
Core definitions of NIA
What is the RICS Code of Measurement Practice?
A guidance note that provides precise definitions to permit accurate measurement of buildings and land, the calculation of sizes, and description or specification of land and buildings on a common and consistent basis.
GEA, GIA, NIA, NSA
What is the GEA as defined in the Code of Measurement Practice and what does it include?
Gross External Area.
GEA is the area of a building measured externally at each floor level.
- Includes footprint of building (perimeter wall thickness, external projections)
- Includes internal balconies, columns, internal walls, lift rooms, horizontal floors below structural/stepped floors regardless of accessibility
- loading bays
- Areas with less headroom than 1.5m
What does GEA as defined in the Code of Measurement Practice exclude?
- External open-sided balconies, covered ways and fire escapes
- Canopies
- Open vehicle parking areas, roof terraces and the like
- Voids over or under structural structural, raked or stepped floors
What is the GIA in Code of Measurement Practice 6th ed. and what does it include?
Gross Internal Area
Includes:
- Areas occupied by internal walls and partitions
- Columns, piers, chimney breasts, stairwells, lift wells, vertical ducts and the like
- Structural, raked or stepped floors are to be
treated as a level floor measured horizontally - Mezzanine floor areas with permanent access
- Service accommodation eg halls, toilets, changing rooms
- voids over stairwells and lift shafts on upper floors
- loading bays
- pavement vaults
- garages
- Atria and entrance halls, with clear height above,
measured at base level only
What does GIA in Code of Measurement Practice 6th ed. exclude?
- Perimeter wall thicknesses and external
projections - External open-sided balconies, covered ways
and fire escapes - Canopies
- Voids over or under structural, raked or
stepped floors - Greenhouses, garden stores, fuel stores, and the
like in residential property
What functional unit of measurement would you use for car parks?
Cost/parking space
What unit of measurement would you use for measuring an office?
Cost/m2 of NIA
What unit of measurement may you use for schools?
Cost/pupil
What unit of measurement may you use for hospitals?
Cost/bed space
In the Code of Measurement Practice 6th ed., what is the definition of NIA and what does it include?
Net Internal Area
Includes:
- Atria with clear height above, measured at
base level only - Entrance Halls [in tenant area, not in common spaces]
- Notional lift lobbies and notional fire
corridors - Built-in units, cupboards, and the like
occupying usable areas - Ramps, sloping areas and steps within usable
areas - Areas occupied by ventilation/heating grilles
- Areas occupied by skirting and perimeter
trunking - Areas occupied by non-structural walls
subdividing accommodation in sole occupancy - Pavement vaults
What is excluded from NIA as defined in the Code of Measurement Practice 6th ed. ?
- Common areas such as hallways, landings, balconies
- Toilets, changing rooms, cleaners rooms and the like
- Lift rooms, plant rooms, tank rooms (other than
those of a trade process nature), fuel stores, and
the like - Stairwells, Liftwells
- Internal structural walls, walls enclosing excluded areas
- Columns, piers etc
- Area occupied by permanent and continuous air conditioning, heating or cooling apparatus and ducting if it renders the area unusable
- The space occupied by permanent, intermittent
air-conditioning, heating or cooling apparatus
protruding 0.25m or more into the usable area - Area with headroom less than 1.5m
- Areas rendered substantially unusable by vir tue
of having a dimension between opposite faces of
less than 0.25m - Vehicle parking areas
What is the build up to an Elemental Cost Plan recommended in NRM?
0 - Facilitating Works 1 - Substructure 2 - Superstructure 3 - Internal Finishes 4 - FF&E (Fittings, Furnishings and Equipment) 5 - Services 6 - Prefabricated units 7 - Works to existing building 8 - External Works 9 - Main Contractor Prelims 10 - Main Contractor OH&P 11 - Project Design Team Fees 12 - Other development/project costs (e.g. cost to acquire land, planning fees, insurances) 13 - Risk 14 - Inflation
Where can you find the formal requirements needed to produce a Cost Plan at different stages?
NRM1 Appendix F
What is IPMS?
International Property Measurement Standards
Property Measurement Standards that supersede NRM. Building function specific.
When was the first IPMS released?
2014 - IPMS: Office Buildings
When was the residential volume of IPMS released?
2016
What is IPMS1?
- The sum of the areas of each floor of a building measured to the outer perimeter of external construction features and reported on a floor by floor basis
- GEA
What is included in IPMS1?
- Basement included. Calculated by taking exterior plane of GF and extending it downwards, or by taking the GIA of the BF and estimating the external perimeter wall thickness
- Balconies, galleries and accessible rooftop terraces are included but should be stated separately
What is excluded in IPMS1?
- Open light wells or upper level voids of atriums
- Open external stairwells that are not an integral part of the structure
- Patios and decks at ground level, car parks, Cooling equipment and refuse areas and other areas that are not fully enclosed are not included but may be stated as a separate measure
What is IPMS2: Office for?
- Measuring the internal area of offices
- Categorising use of space in an office building
What’s the definition of IPMS2: Office?
The sum of the areas of each floor level of an office building measured to the internal dominant face and reported on a component-by-component basis on each floor of the building.
GIA
What is included in IPMS2 Office?
- Atria and the like only measured at GF level
- All areas inside internal dominant face including partitions, columns
- Enclosed passageways between two buildings
- Balconies, galleries and accessible rooftop terraces are included but should be stated separately
What is excluded in IPMS2: Office?
- Open light wells or upper level voids of atriums
- Patios and decks at ground level, car parks, Cooling equipment and refuse areas and other areas that are not fully enclosed are not included but may be stated as a separate measure
What is an internal dominant face?
The inside finished surface comprising of 50% or more of the surface area of a vertical section forming an internal perimeter
What happens if there is no internal dominant face?
The measurement is taken to the wall to floor junction excluding skirting etc
What is IPMS3: Office for?
- Measuring the occupation of floor areas for exclusive use
- IPMS3 is not directly related to IPMS1 or 2, nor a component area in IPMS2
What is the definition for IPMS3: Office?
Floor area available on an exclusive basis to an occupier
but excluding shared facilities and shared circulation areas.
Calculated on an occupier-by-occupier or floor-by-floor basis.
What is inclusive of IPMS3: Office?
- All internal walls and columns within tenant area
- Taken to centre line of shared tenant walls
What is excluded from IPMS3: Office?
Standard facilities. These are parts of the building providing shared or common facilities that do not change over time, such as stairs, cleaners cupboards, escalators, plant rooms, fire refuge areas and maintenance rooms.
What are the 8 component areas as defined in IPMS2: Office?
- Workspace
- Hygiene areas
- Circulation areas
- Amenities
- Vertical penetrations
- Structural elements
- Technical services
- Other areas (incl. storage rooms, internal parking, balconies)
What does BIM stand for?
Building Information Modelling
What is BIM?
The process of creating information models containing both graphical and non-graphical information in a Common Data Environment (CDE)
What are the levels of CAD?
Level 0 - Unmanaged CAD
Level 1 - Managed CAD in 2D or 3D
Level 2 - Managed 3D environment with data attached, but separate model for each discipline (architect, structural engineer etc)
Level 3 - Single online project model with construction sequencing, cost and lifecycle management information.
What are the dimensions of BIM?
3D - Graphical and non-graphical information in a CDE
4D - Same as 3D but also includes construction sequencing. Info about lead times etc, ultimately enabling the creation of a more accurate programme
5D - Includes capital cost information
6D - Includes lifecycle cost information
What role would the QS have if 5D BIM was executed in the design phases of a project?
- To check accuracy of information and fill the gaps. Cost info derived from model will only be as accurate as the information provided, which will generally be basic in the earlier design stages
- QS will be able to pick up on costs not shown on construction model such as temporary works.
- Quantities may not be visible on model but derived from it, such as window mouldings.
What are the benefits of level 3 5D BIM for a QS?
- Data can be queried at any time during a project, information is regularly updated. Can create a “Living Cost Plan”. Cost Reports will be more accurate when issued - currently they are historic dating to the last design release.
- 3D visualisation can reduce the risk of missing anything out
What is the purpose of a tender pricing document?
- To enable a like for like comparison between Tender submissions and Cost Plan
- To enable Cost Consultant to understand where value lies within Contract Sum (foundations, M&E etc.)
- To identify significant differences in pricing to ensure design has been interpreted correctly
- Identify areas of saving that may be negotiated with tenderers whilst in competition
- Form the financial basis of Tender Report
What is a Bill of Quantities?
- A document that provides a list of quantities for a project
- Put together by QS
- Quantities taken from drawings and specification in the tender documentation.
- Requires full specification of project
What is the Bill of Quantities for?
- For PQS to prepare a pre-tender cost estimate. Quantities are multiplied by rates to give costs.
- To be sent out to Contractors during the tender period for them to price
- Can be used as a schedule of rates to price variations
- Can provide the basis for valuations of interim payments
- Provide the basis for preparation of the Final Account
What is a schedule of works?
- Simply lists work to be carried out. Quality should be defined in specification, size and location defined in drawings.
- Allow for pricing of items, builders work, fixing schedules
Who would produce a schedule of work?
- Produced by designers
Why would a schedule of work be used?
- Used on smaller projects or for alteration works
- Alternative to BoQ
- Sometimes form part of tender documentation/Contract Documents along with BoQ, specification etc
What documents form Tender Documents?
- A letter of invitation to tender
- Form of Tender
- Form of Contract to be used
- Tender Pricing Document
- EIR (Employers Information Requirements) for BIM
- Design drawings, possibly BIM model
- Specification
- Tender return slip
What is a schedule of rates?
A list in a Contract setting out costs for items ranging from labour, plant hire and staff (for cost reimbursable day rates), to rates for an extensive number of items (for Measured Term Contracts).
What are the advantages of using a schedule of rates?
- Variations are easier to value and usually cheaper
- Client can stop and start work whenever they like
- Tendering process is easy and inexpensive, so larger pool of Contractors can be invited to Tender (more competitive = cheaper)
- Fast track procurement method as project can be tendered before design is complete
- Flexible in relation to scope and contractual commitment
What are the disadvantages of using a schedule of rates?
- Client does not have final price when committing to works
- Additional resources required to measure works before payment made to Contractor
- Difficult for Contractors to predict long term resource, may result in loss of continuity
- No sense of urgency or risk, so best resource may be taken away from these works
What is a provisional sum?
An allowance in a Contract Sum for a specific element of works that is not yet defined in enough detail for tenderers to accurately price.
What is a defined provisional sum?
An element of work defined in enough detail for the Contractor to have made an allowance in their:
- Programme
- Prelim pricing
- Planning
What is an undefined provisional sum?
An element of work NOT defined in sufficient detail, thus the Contractor cannot be expected to make an allowance in their:
- Programme
- Prelim pricing
- Planning
What is a prime cost sum?
An allowance for the supply of work or materials by the Contractor nominated by the client. This allowance is exclusive of any OH&P/attendance by the Main Contractor.
How are payments for PC sums agreed?
Payments are agreed based on quotes/invoices provided by the Main Contractor. Any additional reasonable percentages for OH&P/prelims are added. This can result in the Contract Sum increasing/decreasing.
What are target costs?
- Relating to Cost Reimbursable Contracts
- Target costs set, allowing Contractor to share cost savings but also bear cost of overruns
What are the benefits of target costing?
- Encourages good collaboration
- Encourages good cost control
What are the disadvantages of target costing?
- Client must have sufficient knowledge to understand what the likely outcome of costs may be
- Client must be good at negotiating target cost
What Contracts have provisions for target costing?
NEC3 ECC - Option C Target Contract with Activity Schedule
NEC3 ECC - Option D Target Contract with Bill of Quantities
What is loss and expense?
Contracts generally give provisions for the Contractor to claim loss and expense resulting from works being materially affected by relevant matters for which the client is responsible for.