Last reviewed 24 October 2023
Inspections underpin safety, quality and compliance in the construction industry. Roland Finch highlights the crucial role inspections play in this feature article.
The philosophy of “Plan, Do, Check, Act.” is often attributed to the American engineer and statistician William Edwards Deming. In simple terms, it represents a methodology for managing processes with the aim of continual improvement.
Of critical importance in the cycle is the need to check whether specified standards and milestones have been achieved. This may be as simple as determining whether rates of progress have aligned with programmes, or whether work has been carried out to a required standard.
In the construction arena this can be done in a number of ways; the use of data is becoming increasingly important, analysing information from things like BIM models and various statistics derived from projects at the many stages from inception to completion and beyond.
One of the most powerful tools is the simple inspection. Data and other information in itself are meaningless without proper understanding, and as many commentators have observed, they can be interpreted in a variety of different ways.
Having somebody with the appropriate skills and experience to undertake the task can significantly improve outcomes for all concerned, and help ensure that a proper picture of the overall situation is available to inform the decision making process.
Inspections can use tools, such as measuring equipment calibrated for the task under scrutiny or data collected either from the work itself or third-party providers and accreditation bodies. This might be in the form of a report or other document, such as the output from a testing procedure.
But the simplest form of inspection is a visual one, carried out by a trained inspector, who will advise on their findings.
Inspections typically fall into one of four categories, listed below.
Compliance inspections — including health and safety inspections.
Inspections will typically take place at specified times during a project; for example, the Building Safety Act 2022 provides for three “gateways” during a construction project — at design stage, immediately before construction begins, and again before a building may be occupied. Usually, this type of inspection will take the form of examination (by the regulator) of documents submitted by the relevant duty holder for each stage of the project demonstrating how it meets the requirements of the Act in terms of Health and Safety provision.
However, there are other points at which inspections may be required. For example, the client may wish to assess the suitability of the project to proceed even before construction is started, while the contractor will usually want to understand site conditions, including things like location and access, before agreeing to tender for the work. And a similar inspection may be undertaken by a prospective occupier before deciding to move in.
Probably the best way to undertake an inspection is by using a defined checklist. But the things to consider will vary, depending upon what we are going to do with them.
Quality and compliance are sometimes considered interchangeable. However, in some situations, use of the term “quality” can be subjective. Compliance, as discussed later, relies on a set of measurable standards. There are several processes and procedures designed to assess quality, both in terms of performance, cost and time. Quality inspections may be used to assess whether production routines or construction processes are being followed, with the aim of assuring the quality of the product or construction, or sometimes the perception of an end user, but without necessarily objectively testing the product or construction itself.
Compliance inspections are mainly used to ensure that the finished product or construction meets all the specified requirements contained within the contract documents, including the drawings, specifications and contract conditions. If set out correctly, the drawings will usually determine the location, shape and size of the individual components and the dimensions of the building itself. The specification more commonly includes performance requirements with regard to things like durability, compressive, impact and tensile strength, as well as things like thermal performance, resistance to passage of sound, lighting levels and so on. It can also include things like cost and time, where these are critical measures. The contract conditions will describe the circumstances under which the work is to be carried out, including the responsibilities of the various parties involved.
Each of these “properties” will be usually described by reference to a specified standard, with details of how compliance is to be measured, a pass/ fail threshold, and any evidence required to support the assertion. In these scenarios, the inspection will look at the work done, and observe whether the criteria have been met. It could mean inspecting the work itself, test results, or other documents, for example to check whether an item has been installed in accordance with the manufacturer’s recommendations.
Some construction contracts, however, place responsibility for determining compliance with one of the consultants — often expressed as being “in the opinion of…”. In these cases, an inspection will usually be used as part of the process to form that opinion.
Inspections are often undertaken once the work is offered up as complete (or from the contractor’s perspective, to decide whether it is in a suitable condition to be offered). However, it is usually prudent to carry out inspections as the work progresses, to ensure that the correct products and methods are being used, and to avoid potentially expensive remedial work at a later date. Progress inspections are also used to trigger “interim” payments for work completed, rather than waiting for a certificate of completion for the whole job.
These inspections can also identify poor performance, particularly in the area of health and safety. The Construction (Design and Management) Regulations 2015 (CDM) require that a Construction Phase Health and Safety Plan is prepared for each qualifying project, and a progress inspection can identify failings in following the plan and bring about corrective action to resolve problems early.
Although at first glance the title might sound a bit misleading, completion inspections are used to determine whether the work complies with all the regulatory requirements have been met for the work and the project. As already noted, some of this work can take place during the project, rather than immediately before its overall completion, and in the case of things like compliance with planning permission, building control, and the particular requirements of legislation such as the Fire Safety Act 2021 and the Building Safety Act 2022, this will often take place before construction work begins. For example, CDM includes a requirement that a principal designer should be appointed (in writing) “as early as possible in the design process, if practicable at the concept stage.”
Inspections will be needed as part of these activities, and also to ensure that the necessary certificates and statutory permissions have been received as work proceeds. There is, for example, an inspection requirement under the Building Safety Act for certain types of ‘higher risk’ building whereby the Building Safety Regulator will need to undertake site inspections before a building control completion certificate is issued.
Who can undertake inspections?
Depending on the project size and subject, inspections will be carried out by a range of people. Specialist inspectors may also be needed for particular topics, such as the principal designer and contractor under CDM, or for specialist subjects, such as accessibility or environmental considerations.
This will usually depend on the nature of the inspection itself. For some inspections, a designated person will be required, for example when undertaking statutory tasks such as building control, electrical or gas safety, or the Regulator for certain health and safety matters.
Construction contracts often stipulate relevant people, such as the named Architect, Engineer or Contract Administrator for “day to day” supervision. Either way, the inspector will need the necessary skills and experience to ensure everything is carried out correctly.
A checklist should be developed for each inspection type, as these will vary depending on what is being inspected, its frequency, and who is responsible for the inspection. This will ensure consistency, but as a general rule, site inspections will be needed before work is started, and also at various stages throughout the construction process, especially for work which may be covered up later, such as excavations, foundations, drainage and suchlike. There will also be inspections before completion, to determine whether completion may be formally certified, and identify any outstanding work to be completed prior to that certification.
An inspection regime will also be needed after completion, as part of an integrated maintenance and repair plan. Recent concerns following the tragedy at Grenfell Tower in 2017, and the use of Reinforced Autoclaved Aerated Concrete (RAAC) in buildings have highlighted the problems which can result if records of inspections, together with their associated results and recommendations are not available when needed.
It is important to keep detailed records of inspections and their results. A comprehensive inspection plan will become a critical part of the “golden thread” of information mandated under the Building Safety Act, (initially for higher risk buildings, but expected at some point to be extended to other buildings) defined as: “the information that allows you to understand a building and the steps needed to keep both the building and people safe, now and in the future”.
This information may also form part of a Construction Phase Plan or Health and Safety File for the project, required by the CDM Regulations.
“Golden thread” information is required to be kept digitally, perhaps as part of a Building Information Model (BIM) and there are a number of commercially available proprietary software tools and applications to assist in this process.
Further information and guidance on the golden thread and the Building Safety Act are available from the HSE website.
Inspections are an integral part of the construction process. As well as enabling progress, they help to identify risks for interested parties which can then be managed appropriately.
But most importantly, well planned inspections can identify and head off potential problems before they appear, saving time, money and resources, and therefore making the whole process more efficient, which benefits everyone.