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#013 Quantification and Costing of Construction Works (PART 1) 📐🧮

Updated: Oct 18, 2021

Hello friends 👋

This week I’m going to briefly go through the Quantification competency. I like this competency as it involves both pre and post contract knowledge. In my short career, I’ve mainly worked on projects in the pre-contract phase, but I’m slowly pushing to address this balance.

Like most APC competencies, Quantification is a vast competency, so it’s unlikely you will know everything, but again you will be expected to understand the basics.

I’ll follow the format as in previous weeks by going through the RICS pathway guide and providing a brief breakdown of the Level 1 elements.

DISCLAIMER: The following is not an exhaustive set of notes, but its an attempt to help those who, like me at the beginning, did not know where to start! Please feel free to let me know if I have said anything incorrect or out of date!

So what is the ‘Quantification and Costing of Construction Works’ all about?

The RICS describe it as the following:

This competency covers the measurement and definition of construction works in order to value works and control costs, which includes the various methods of quantifying and pricing construction works used throughout a project. They must have a thorough understanding of the specific methods used on their projects.

Level 1 is all about the following:

Demonstrate knowledge and understanding of the principles of quantification and costing of construction works as a basis for the financial management of contracts.

This is an important competency because it's all about how you calculate and measure quantities. It’s a set of skills that are vital during pre-contract work when you are preparing estimates and cost plans, and even more vital in the post-contract stage because it’s how you will value works the contractor has undertaken.

The quantification of construction works (including both measurement and definition) & the measurement of buildings and structures to agreed standards

To be competent at quantification of construction works, you must have a sound understanding of construction technology. In my post about construction tech, it’s why I said that construction technology is one of the most important competencies because it’s interlinked with everything.

You need to be able to know how to measure different types of construction. To do this you need to know how elements are constructed. As a starter for ten, you should have basic math skills to calculate perimeters, areas, volumes and percentages. You can then use these skills to calculate the quantities for particular construction works.

As an example, let's take a pile cap that is 4m long x 4m wide x 1m deep. To construct the pile cap you will need the following:

  1. Concrete – an m3 measure and because we are dealing with relatively simple shapes its quite straightforward, the volume of concrete = l x w x h —> 4 x 4 x 1 = 16m3;

  2. Formwork – a m2 measure which is essential the perimeter of the shape x the depth; therefore – (4m x 4 (number of sides)) x 1 = 16m2;

  3. Reinforcement – a tonnage measure – Let's say reinforcement is required at 125kg/m3. To get the tonnage of steel reinforcement we multiply the volume of concrete (16m3) x (125/1000) = 2t

That’s a simple breakdown of a pile cap that I would measure out for an estimate/cost plan. A BQ would be a lot more detailed as you may need to individually measure out reinforcement bars etc. Also, the above example does include measuring out the excavation and disposal you will require to place the pile cap into the ground … so bear that in mind.

Top tips for learning how to measure construction activities:

  1. Watch how things are done on-site: This is easier said than done but if you are site based please take the time to watch how contractor’s build things! It’s an invaluable experience, and although most processes are similar, some contractor’s might do things more efficiently than others and you can draw on this experience in your work!

  2. Learn from more experienced QS’s: The way I learnt how to measure was by learning from the senior staff around me. I was fortunate to have a very knowledgeable group of senior mentors who patiently taught me how to measure. I don’t know everything yet, but I can do most of the basics. More often than not they will explain things to you, you just need to ask!

  3. YouTube videos: When I come across novel construction activities I generally just youtube the topic and loads of videos turn up. YouTube is a great resource and there are a plethora of construction videos on there. I would say that you need to filter out non-UK construction for some things as international safety methodology probably wouldn’t go down too well here. But for the most part, it’s all very good and you can see the sequences of operation. The sequences of operation are what you tend to measure and price so if you can pick up on that it will really be of great benefit.

  4. Methods of Measurement: Take this with a pinch of salt, but methods of measurement like NRM1 and NRM2 will usually tell you WHAT needs to be measured but not HOW it’s measured. It’s useful for preparing a take-off list for items that you need to measure, but I would still use tips 1-3 to learn how to measure the items.

The various standard methods of measurement

Standard methods of measurement provide a uniform basis for the industry to produce estimates/cost plans and pricing documents like bills of quantities. There are many variants of them and many vary by sector. Here’s a small list:

  1. New Rules of Measurement 2 – this covers general construction work and it replaced the SMM7 (Standard Method of Measurement 7). Most construction projects in the UK will use these two as a basis;

  2. Railway Method of Measurement – covers general construction work along with specialist railway construction activities;

  3. Highways Method of Measurement – covers general construction work along with specialist highway construction activities;

There are also methods of measurement for other disciplines and others for international requirements. The above are the ones I’m familiar with.

The cost of construction works

This is about how you pricing the construction works you have just measured. Pricing information generally comes from three main sources depending on the level of estimate you are doing.

  1. BCIS – Building Cost Information Services – This is the RICS’s benchmark database for various types of projects. You can use this to get benchmark information for functional, floor area and other estimates. You can also get benchmark information for specific work elements.

  2. Pricing Books – i.e. books like SPONS which have various packages which provide component cost prices for all sorts of work items. These are prices at a specific point in time so you need to take prices in these books with a pinch of salt. Nevertheless, they can provide a good indication of what a work activity will cost.

  3. Previous projects / tendered rates – If you have access to previous project data including final account costs and tendered rates this is ideal. Final account costs are infinitely better than most other sources as these are costs that have materialized and should be relatively recent. Tendered rates are good but they are just not as good as final account rates. This is because tendered rates may not take into the true cost of that activity as that work progressed.

The above is a basic breakdown of Level 1 Quantification. If you have any questions on this competency give me a shout!

So far I’ve covered:

  1. Design Economics and Cost Planning;

  2. Construction Technology; and

  3. Quantification and Costing of Construction Works.

Next week I will write up a post on Project Financial Controls and Cost Reporting!

Have a great week folks! 👍

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