As-built drawings and record drawings

On building projects it is common for changes to be made during construction because of circumstances that emerge on site. These changes can be relatively minor or can be very significant.

As a result, it is common for the client to require that as-built drawings are prepared, either during the construction process or when construction is complete, to reflect what has actually been built. The contractor will generally mark up changes to the ‘final construction issue’ drawings on-site using red ink, and these can then be used by the consultant team to create record drawings showing the completed project. This information may be supplemented by as-built surveys.

These record drawings (sometimes referred to as 'as constructed' drawings) may be required for the Health and Safety File or the operation and maintenance manual issued to the client on completion of construction.

Apart from registering on site changes to the engineers' and architect's drawings it is essential that specialist trade contractors record what has been installed on site. Records of installations such as under-floor cabling in city offices is a particular problem because successive tenants cut off, but leave in, their predecessors cables then instal their own systems. Without cabling records this can prove very problematic for subsequent companies that occupy the premises.

The client’s facilities management team must keep record drawings up to date, incorporating details of future modification to the building. If they do not do this, ultimately, surveys may become necessary to re-create accurate measured drawings.

The requirement to produce as-built drawings and record drawings must be set out in tender documentation, and should not be assumed to be part of ‘standard’ services. It can be a time-consuming exercise, and as the project team will be keen to move on to other jobs, it is important that adequate retention remains to ensure completion of as-built and record drawings.

If a building information model has been produced, this must be updated to reflect any changes to the design, and then issued to the client in a form that the facilities management team can continue to develop.

NB The RIBA Plan of Work 2013 defines 'as constructed' information as: Information produced at the end of a project to represent what has been constructed. This will comprise a mixture of ‘as-built’ information from specialist subcontractors and the ‘final construction issue’ from design team members. Clients may also wish to undertake ‘as-built’ surveys using new surveying technologies to bring a further degree of accuracy to this information.’

Design Framework for Building Services 5th Edition (BG 6/2018), written by David Churcher, John Sands & Martin Ronceray, and published by BSRIA in June 2018 suggests that record drawings (in relation to buildings services) are:

Drawings showing the building and services installations as installed at the date of practical completion. The main features of the record drawings should be as follows:

The drawings should be to a scale not less than that of the installation drawings.
The drawings should show locations of all the mechanical, electrical and public health systems and components installed including ducts, pipes, cables, busbars, plant items, pumps, fans, valves, dampers, control devices, strainers, terminals, electrical switchgear and components, security and fire sensors and control equipment.
The drawings should be labelled with appropriate pipe, duct and cable sizes, pressures and flow rates.
The drawings should have marked on them positions of access points for operating and maintenance purposes.
The drawings should not be dimensioned unless the inclusion of a dimension is considered necessary for location.

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Apart from registering on site changes to the engineers' and architect's drawings it is essential that the specialist trade contractors reflect what has been installed on site.

Records of underfloor cabling in city offices is a particular problem because successive tenants cut off but leave in their predecessors cables and providing space is available install their own systems. Without cabling records this can prove a nightmare for say the fourth company to occupy the premises.

There is an issue relating to the method or convention for recording site changes during construction. The issue is that site changes need to be highlighted or made to stand out in order to identify them. This article mentions use of red ink to signify changes, but this is no use when the architectural drawing is a mass or various lines of various colours.

There needs to be a standard way of highlighting changes or revisions on a drawing and it must be easily understood and obvious.

When applying for an amendment of a building warrant it is necessary to show revisions when submitting drawings for local authority approval. These amended drawings should clearly show what has changed from the original approved drawings. This means that as-built drawings alone are not sufficient, unless it is easy to tell what is different from the original approved drawings. The original drawings have presumably already been assessed and approved, so all that needs to be checked is what has changed to ensure the design is acceptable.