As-fitted drawings are record drawings that show a building, installation or system exactly as it was constructed and installed, rather than as it was originally designed. They are produced at the end of a project and form part of the handover documentation passed to the client, the facilities management team and the health and safety file.

The term causes more confusion than it should. As-fitted, as-built and as-installed are used interchangeably across the UK construction and engineering industry, and in most contracts they mean the same thing. Where a distinction is drawn, it is usually one of scope rather than substance.

As-fitted, as-built and as-installed — what is the difference?

As-built is the most widely used term in UK construction. It generally refers to the complete record of the finished works, covering structure, architecture and services.

As-fitted is used more often in building services, fit-out and mechanical and electrical work. It tends to describe the record of what was physically fitted or installed — pipework routes, containment, ductwork, plant positions, electrical distribution — rather than the base structure.

As-installed is used most commonly in process, industrial and telecoms environments, and typically refers to equipment and systems rather than the building fabric.

In practice, if your contract asks for as-fitted drawings, it is asking for accurate record drawings of the installation as completed. The distinction between the three terms rarely changes the deliverable. What matters is the scope defined in the contract and the level of detail expected. Our note on redline markups versus as-built drawings covers the related question of where the source information comes from.

When as-fitted drawings are required

Most UK construction and engineering contracts require as-fitted or as-built drawings at practical completion. The requirement usually arises from three directions at once.

The contract itself will specify record drawings as a deliverable, often tied to a payment milestone or to the release of retention. The CDM Regulations 2015 require the health and safety file to contain the information needed for safe future maintenance, modification and demolition, and record drawings are central to that. And the incoming facilities management team needs accurate documentation to operate and maintain the building.

For higher-risk buildings, the Building Safety Act 2022 has added a further layer through the golden thread requirement, which expects accurate building information to be maintained and handed over in a structured, accessible form.

What as-fitted drawings should show

The level of detail depends on the discipline and the contract, but a competent as-fitted package for a building services installation would typically show:

• Final routes, sizes and levels for pipework, ductwork, containment and cabling, including any re-routes agreed on site
• Locations of all valves, dampers, isolation points and access points, particularly those concealed in ceiling voids or risers
• Plant and equipment positions with actual model references and maintenance clearances
• Distribution board positions with circuit schedules reflecting the installed circuits
• Fire alarm and emergency lighting device positions as installed
• Drainage and below-ground services runs and invert levels where applicable

Critically, the drawings must reflect what is physically there. A set of issued-for-construction drawings with a new revision letter and an as-fitted stamp is not an as-fitted drawing, and it will not satisfy a competent client or building control officer.

How as-fitted drawings are produced

For most projects, as-fitted drawings are produced from the original design drawings updated with the record of site changes. Site engineers mark up changes during installation — on printed drawings in red pen, as PDF annotations in Bluebeam, or as photographs and sketches. These markups are then incorporated into the native CAD files.

This is the reason the process so often runs late. The markups exist, but converting them into finished drawings takes drafting time that most contractors do not have spare at project closeout. Our redline markup incorporation service exists precisely for that bottleneck.

A measured survey is only necessary where original drawings do not exist, or where the record of change is genuinely missing — typically on refurbishment of older buildings with no documentation. For a project you have just completed, you almost certainly already hold everything needed. We cover this distinction in detail in our comparison of as-built drawings and measured surveys.

Formats and deliverables

The standard deliverable is editable AutoCAD DWG files with matching PDF issue copies. Most contracts require both: the DWG so that future design teams can work from the drawings, and the PDF for inclusion in the operation and maintenance manual and the health and safety file.

Drawings should follow the project CAD standard — correct layering, line weights, title block fields completed, and a revision code and description that make the change history traceable. Some contracts additionally specify file naming conventions, folder structures, or delivery through a common data environment.

Getting as-fitted drawings produced

Outsource CAD produces as-fitted, as-built and as-installed record drawings for UK contractors, building services firms and engineering consultancies. We work from site markups in any format — scanned prints, Bluebeam PDFs, annotated drawings or photographs — and return editable DWG files with PDF copies, typically within 24 to 48 hours.

Pricing is per markup rather than hourly, so the cost is known before the work starts and can be priced into a package at tender stage. Full details of our as-built and record drawing services, or contact info@outsourcecad.com or +44 28 9009 8876 to discuss a live project.

Frequently asked questions

Are as-fitted and as-built drawings the same thing?

In most UK contracts, yes. As-fitted is used more commonly in building services and fit-out work, as-built more commonly in general construction, but both describe record drawings showing the completed works. Check the contract for the required scope rather than assuming a difference based on the term used.

Do I need a survey to produce as-fitted drawings?

Usually not. Where original design drawings exist in CAD and site changes were recorded through markups, photographs or annotated PDFs, as-fitted drawings can be produced directly from those records. A survey is only required where the original drawings are missing or no record of change was kept.

Who is responsible for producing as-fitted drawings?

Responsibility normally sits with the contractor who carried out the work, with the principal contractor consolidating the package for handover. Each subcontractor supplies the record of their own installation. In practice, gaps appear where subcontractor markups are not collected during the project.

What format should as-fitted drawings be delivered in?

Editable AutoCAD DWG files with matching PDF copies is the standard. The DWG allows future design teams to work from the drawings, and the PDF goes into the operation and maintenance manual and health and safety file. Some contracts specify additional naming conventions or delivery through a CDE.

How long do as-fitted drawings take to produce?

Turnaround depends on volume and the clarity of the markups. Individual drawings can typically be turned around within 24 to 48 hours. A full package for a completed project depends on the number of drawings and how complete the site records are.