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How to do a Construction Quantity Surveying (QS)


  • Oct 26, 2021 | Kinjal Shah

A construction QS is counting or measuring items on drawings to determine how many resources (material, labour, equipment, etc) are needed to complete a job.

Why QSs Are Necessary for Construction Projects

Generating extremely accurate construction estimates for construction work is crucial for success. You need to know the precise amount of materials on structures that are often very large and complex, and you’ll be bidding on multiple jobs at once. A rough (ballpark) estimate might leave you leeway with materials you could reuse later, but you’ll have to pay for them up front, which could cramp your cash flow. And, adding a significant markup to cover your costs could price you out of the job. Many general contractors do QSs to check your work, and some will even want to see your completed QSs.


Who Is Responsible for Completing a Construction QS?

In large, well-established construction contracting companies, often a billing and tendering department (project controls) shares responsibility for QS and progress invoicing compilations. Often a dedicated billing engineer is at the project site, leading the work and providing feedback to HO.

In smaller companies, until it’s feasible to hire more staff, the owner or a single estimator will handle all QSs, but this practice is unsustainable for the long term if the business aims for substantial growth.

Material Takeoffs: When there are material QSs, which involve performing measurements and applying formulas to determine how much material is needed. Most trades also perform material QSs. Some examples include measuring:

– Running meter for installing tile skirting, window sills, electrical cables, mechanical piping.

– Surface area (square meter) for installing flooring, application of plaster, paints, or pouring concrete grade slabs.

– Volume (cubic meter) for civil and site work such as excavation or pouring concrete slabs or walls.

Quantity QS result in the exact amount of materials needed for a job. Eg. Cubic meter of concrete

Material QSs require assigning items and assemblies to your measurements so you can calculate quantities based on how materials are packaged E.g. For 1 cum of concrete, you would need 7 bags of concrete, 1200 Kgs of coarse aggregates, 800 kg of fine aggregates, 125 lts of water.

The Real Purpose of a QS in Construction

The most common mistakes that happen in the QS process come down to missing deadlines and inaccurate measurements. This leads to improper and timely invoicing.

The QS itself is just one part of the preconstruction process, leading up to creating an estimate and proposal. Your objective with performing QSs is to create a clear picture of the cost of materials needed to do a particular job. When you’ve determined that number, you can then begin to account for non-material costs, like labor hours, overhead, equipment requirements, and any other indirect costs. The construction estimate is where you apply all of these costs together to generate a total project cost.

A cumbersome, time-consuming QS workflow means less time for your team to compile a detailed and accurate running bill (RA). Setting a goal for speeding up your QS process could be the best way to put your company on a path to growth as it would help improve cashflow and profit margins.

How to Speed Up Your QS process and Progress Invoice (Running Bills) cycle

QSs is done usually in excel. This is time-consuming and prone to human error. The time crunch of using excel means that invoices are compiled late.

Using a cloud based QS method eliminates these drawbacks. Such tools for QSs offer substantial benefits such as:

1. One single database of quantities

2. Up to 10 times faster compilation of measurements

3. Digital storage of information for easy access

4. Simplified collaboration of data among team members

5. Ability to work from more than one device or location

6. Reduced rework and manual data entry

7. Higher levels of accuracy in measurements

With the right software tools, digital QSs set your team up for more success during estimating by allowing you to seamlessly create a bill of materials for suppliers and incorporate labor and materials using pre-built and customizable libraries. But that’s not all: they also provide insights into your team’s performance and schedules. A digital QS tool that offers a bid calendar allows you to understand which bids each team member is working on at a given time, what their workload looks like, and what their win rate is. You can see where someone is succeeding or where they are struggling and might need help. You can also export data from your digital QS platform to determine the types of jobs that bring in the most profit so you can make better long-term decisions about which projects to seek out and bid on.

What Happens after the Construction QS?

When your measurements are finalized, it’s time to create an invoice. This is where, a real time invoice can be generated as the QS’s measurement sheet is linked with Bill of Quantity (BoQ) items. You can generate an invoice and provide it to the client in the format they prefer, excel, PDF, or online access to your invoice for reviewing details.

What Are Cloud QS and Progress Billing Software?

A cloud QS is simply a construction QS performed on software that is cloud-based rather than desktop-based. To understand what this means, remember that before the cloud became common, typical software tools were available on a license basis for individual devices – typically desktop computers. Companies had to buy a license for each computer that the software would be installed on, and it could only be accessed via that particular device. A user would log on to their computer to do a QS and then, if any colleagues needed to be involved, they’d have to download the plans and email them to their coworker, who would then download to their desktop and upload into their own copy of the software.

Not only is this a time-consuming process, but it also opens up more room for – you guessed it – user error. With no way of knowing for sure which version of a file was the most up-to-date, rework would often occur, and if one person was out of the office unexpectedly, work would grind to a halt with no way to access their progress or see what they’d been working on.

Many old-fashioned desktop construction QS software options still operate in this outdated way, believe it or not. So be sure when you’re evaluating tools to choose

Cloud QS software will make your QS process faster, smoother, and more accurate. It will transform the way your company does preconstruction and can be the catalyst for enormous growth and increased profits.


But remember that the best QS tool is still only a tool, and you need skilled estimators!

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