Building Measurement

New Rules of Measurement

Andrew D. Packer, Andrew Packer

• Publisher: Routledge
• Year: 2016
• eBook ISBN: 9781317561491
• Topic: Technology & Engineering
• Subtopic: Construction & Architectural Engineering
• Index: Technology & Engineering

Measurement of buildings is the core skill of the quantity surveyor. It underpins the procurement, management, delivery and subsequent commissioning of a completed building, and must now be completed using New Rules of Measurement 2 (NRM 2).

In this much-needed new measurement textbook, the measurement of the most common building elements is described using NRM2. Extensive worked examples including fully up to date hand-drawn diagrams and supporting take-off lists ensure that the reader develops a confidence in their ability to measure using NRM2 in practice.

A practical step-by-step approach is used to explain and interpret the detail of the specific Work Sections of NRM2, covering a broad range of different trades, including mechanical and electrical systems; external works; groundwork; masonry; joinery; and internal finishes.

Presuming no prior knowledge of measurement or NRM2, and fully up to date with current practice, including consideration of Building Information Modelling, this is the ideal text for students of measurement at HND or BSc level, as well as practitioners needing a crash course in how to apply NRM2.

1 Introduction

1.01 Getting started

1.02 Context and purpose

1.03 General principles

1.04 The classification system

1.05 Traditional tendering

1.01 Getting started

Before starting we need to establish the purpose and intention of measurement. If you were asked to measure a building, or the room you are in right now, most people would find a measuring tape, a clipboard and something to write with. You might sketch out the plan shape of the building or room and write the individual lengths and widths down as you go along.

ACTIVITY: If you can, try sketching the plan shape of the room you are in right now. Get a tape measure and record the principal lengths and widths and annotate your sketch of the floor layout (plan) by recording the plan dimensions. It doesn’t matter if you haven’t got a tape measure to hand – you can simply ‘pace the room’. This will obviously depend on how big your stride is so, for the purposes of getting you started we will just assume that one of your strides is equivalent to one metre.

TIP: most rooms are a regular shape (rectangular), so you will only need to measure one width and one length. Older buildings (and some poorly constructed new ones) may be ‘out of square’, so the above technique may not be appropriate. One way of checking whether a room is square is to measure both of its diagonals (from one corner of the room to the other). If the two diagonal dimensions are the same then it is a safe bet that the room is square and each of the corners is at 90 degrees.

Being able to read and draw to scale is an important part of what quantity surveyors call measurement.

Once you know the length, area or volume of the various components that go together to make up a finished building, you are in a position to allocate costs based on the units that you have measured. For example, if you were measuring a skirting board and you knew how much it cost per metre, finding the total cost once you know the internal room dimensions (perimeter length) is straightforward (Figure 1.1).

Recording dimensions from finished buildings is one way of finding out how much the building will cost. Once you are able to ‘read’ scale drawings and ‘record dimensions’ it becomes possible to cost buildings even before they are built. In essence, this is the service that a quantity surveyor offers to a client.

Figure 1.1 Dimensioned plan of room.

One of the first things that anyone thinking about commissioning a new building wants to know is ‘how much?’ By measuring the individual components and then allocating a cost to these, the likely finished build cost can be established. Simply adding together all of these individual components will give the total building cost.

OK, so this sounds simple enough but there are some other things to consider, especially when we are dealing with an idea that was ‘in someone’s head’ and is now in the form of a drawing rather than a finished building.

With a finished building we can see its quality (or not) both in terms of the materials used and the workmanship. If we are measuring from a drawing this isn’t going to be so obvious. This is of course significant when we are applying costs to our measured items. Consider the skirting we measured earlier around the perimeter of a room. A softwood skirting (pine) is likely to cost less than a hardwood (oak) equivalent; so we need to have some indication of the quality of the materials and the standard of workmanship required before we can state with certainty what things will cost.

So a set of measurements from a scale drawing isn’t enough on its own. In order to cost a building we need to know two things: how much is there (the quantity) and what quality of finish/standard is required/expected (the specification).

1.02 Context and purpose

To the uninitiated, the phrase ‘building measurement’ brings to mind the fixed notion of a tape, a building and some numbers. One thing it probably does not immediately imply is cost and forecasting. Yet the purpose of measurement in this context is inextricably linked with providing an assessment of the cost of a building long before work has commenced on site. Initially, and most importantly, someone requires the provision of a new building. Normally they are likely to approach an architect so that their ideas and intentions can be set down on paper. It is very likely, even at this early stage, that they will need to know how much the building design proposals are going to cost (Figure 1.2a, b).

Armed with a set of drawings, a scale rule and a calculator, measurements can be taken from these drawings and a document produced. This document identifies in some detail the component parts of the proposed works, together with their quantity, and will allow construction costs to be allocated to the appropriate parts of the building. Having costed each component, a forecast for the scheme can be established (Figure 1.3).

Figure 1.2 A building is proposed – how much will it cost?

Figure 1.3 A forecast of the proposed scheme is prepared.

To enable this forecast of cost to be made with any confidence, a number of basic principles must be in place. It is very important that none of the building operations are overlooked and that the items which have to be costed are presented in a recognisable form. The consequence of an error in measurement or ambiguity in a description could result in the client being ill-advised with regard to the eventual cost of building operations.

1.03 General principles

Having identified the purpose of measuring building work it is necessary to establish the general principles that will ultimately result in a document which is mutually understood and conveys the scale and extent of the construction. A consistent approach is necessary both in terms of presenting this finished document and setting down dimensions so that others are able to understand our approach (Figure 1.4).

It is not hard to imagine the confusion that would result if everyone adopted their own set of rules when measuring building work. It was exactly this situation that prompted the publication in 1922 of the first nationally recognised (UK) set of rules for the measurement of building work. An indication of the chaotic state of affairs that prevailed prior to this publication can be gleaned from reading the preface of this very first edition. Phrases such as ‘diversity of practice’ and ‘idiosyncrasies of individual surveyors’ suggest a picture of confusion and doubt for the hapless early twentieth-century contractor. Almost a century later, the same set of principles still apply. Now in an eighth edition, the current document NRM2: Detailed Measurement for Building Works provides the basic principles for the measurement of building work.

Figure 1.4 Clearly understood set of documents.

A report commissioned by the RICS Quantity Surveying and Construction Professional Group (Measurement-based procurement of buildings; 2003) claimed that the (then) current version of the Standard Method of Measurement (SMM7) was out of date and represented a time when bills of quantities and tender documents were required to be measured in greater detail than was warranted by procurement practice. At the same time it reported that the ri...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Acknowledgements
• Abbreviations
• 1 Introduction
• 2 Traditional approaches to booking dimensions and bill preparation
• 3 Mensuration
• 4 Document production
• 5 Substructures
• 6 Masonry work
• 7 Concrete-framed buildings
• 8 Steel-framed buildings
• 9 Structural timber
• 10 Roof coverings
• 11 Windows, doors and standard joinery
• 12 Floor, wall and ceiling finishes, dry linings, internal partitions and suspended ceilings
• 13 Drainage above ground, electrical and plumbing installation
• 14 Disposal systems below ground
• 15 External works
• Appendix I Common abbreviations used when booking dimensions
• Appendix II Geometric formulae
• Index