Every M&E contract ends the same way. The installation is complete, the commissioning sheets are signed, the retention is in sight — and someone asks for the as-built drawings for the health and safety file.
This is the point at which a lot of otherwise well-run projects come unstuck. Not because the work was poor, but because nobody planned for the paperwork. The redlines are scattered across three site engineers' drawing rolls, two phones' worth of photographs and a folder of marked-up PDFs. The handover date is fixed. And converting all of that into a coherent set of record drawings is a job nobody has been given.
This article covers what the CDM Regulations actually require, where the M&E contractor's obligation sits, and how to produce compliant as-built drawings without commissioning a survey.
What CDM 2015 actually requires
Regulation 12 of the Construction (Design and Management) Regulations 2015 requires a health and safety file to be prepared for every project involving more than one contractor. The file must contain the information that anyone carrying out future construction work on the structure would need in order to do it safely.
The regulations do not hand you a checklist of drawings. What they specify is a purpose: the file exists so that the next person who opens up a ceiling void, isolates a circuit or replaces a plant item can do so without discovering something unexpected and dangerous. HSE guidance L153 sets out the kind of information that satisfies that purpose — and record drawings showing services as actually installed are central to it.
The important word is installed. A set of design drawings exported to PDF at practical completion is not a health and safety file record. If the drawings show the system as it was designed rather than as it was built, the file does not do what Regulation 12 requires it to do.
Where the M&E contractor sits in this
The principal designer prepares the health and safety file during the pre-construction phase and develops it as the project progresses. Where the principal designer's appointment ends before the project does, the principal contractor takes it over and hands the completed file to the client.
But neither of them can invent the M&E content. They rely on it being supplied. Every contractor on a project has a duty to provide the principal designer or principal contractor with the information relevant to their own package — and for an M&E contractor, that means the record of what was actually installed, where it runs, and what a future engineer needs to know about it.
In practice this is where the chain breaks. The principal contractor asks for the M&E as-builts a fortnight before handover. The M&E contractor has the redlines but not the drafting resource. The file gets submitted with a gap in it, or with design drawings standing in for record drawings, and nobody notices until the building is three years old and someone needs to trace a circuit.
What the M&E element of the file should contain
For a typical commercial or industrial building services package, the record drawings should show:
- Final routes and sizes for all distribution — containment, ductwork, pipework and cabling — including any re-routes agreed on site
- Locations of all isolation points, valves, dampers, and points of access, particularly those concealed above ceilings or within risers
- Distribution board schedules and circuit charts reflecting the installed circuits, in line with BS 7671
- Plant locations, equipment references and access and maintenance clearances as built
- Fire alarm zone plans and emergency lighting layouts showing installed device positions
- Earthing and bonding arrangements as installed
- Any residual hazards a future worker would not expect — live retained services, restricted access, unusual sequencing
Alongside the drawings sit the operation and maintenance manuals, commissioning records and equipment data. The drawings are what make the rest of it navigable.
Why the drawings are so often missing
Three causes account for most of it.
Timing. As-built production is scheduled at the end, when site teams are demobilising and attention has moved to the final account. The redlines that should have been consolidated month by month are instead gathered in a rush.
A misunderstanding about surveys. Many site teams believe as-built drawings require a measured survey or laser scan, assume that is expensive, and put off the decision until there is no time left. For the majority of M&E packages this is simply not true — see below.
Resource. Most M&E contractors in the twenty-to-two-hundred staff range have no in-house CAD capacity. The drawings are a genuine skill and a genuine time cost, and there is nobody sitting idle to absorb them.
You probably do not need a survey
Where the original design drawings exist in CAD, and where site changes were recorded — on marked-up prints, annotated PDFs, Bluebeam comments or even photographs — as-built drawings can be produced directly from those records. No survey, no scanning, no return visit.
The design drawings become the base. Each redline is worked through and incorporated. The output is a set of record drawings in DWG with PDF issues, showing the installation as it stands.
A measured survey or point cloud scan is only necessary where the original drawings do not exist at all, or where the record of change is genuinely absent — a refurbishment of an older building with no documentation, for instance. For a project you have just finished building, you already hold everything needed. The distinction is covered in more detail in our guide to as-built drawings versus measured surveys.
The Building Safety Act has raised the bar
For higher-risk buildings, the Building Safety Act 2022 introduced the golden thread — a requirement to maintain accurate, accessible, up-to-date building information through design, construction and occupation, with the information handed over at the point the building is registered for occupation.
Building services information sits squarely inside that. A drawing set that was approximately right at handover and has not been touched since does not meet a golden thread standard. Even outside the higher-risk category, client and insurer expectations of documentation quality have moved considerably in the last three years, and they are not moving back.
A practical process for your next handover
The fix is procedural rather than technical.
Agree ownership at contract stage. Name the person responsible for collecting redlines, the format they are to be submitted in, and the frequency. A single named engineer per project is enough.
Collect monthly, not at the end. A markup made and submitted in the month it happened is accurate. The same markup reconstructed from memory nine months later is a guess.
Accept whatever format is easiest on site. Scanned prints, PDF annotations, phone photographs of a marked-up drawing — all of it works. Insisting on a particular format is how you end up with nothing.
Budget the drafting. Treat as-built production as a line in the package, not an overhead absorbed at the end. It is a known, quantifiable cost.
Have the capacity lined up before you need it. Whether in-house or outsourced, the drafting resource should be arranged before the handover clock starts.
Getting the drawings produced
Outsource CAD produces as-built and record drawings for UK M&E and building services contractors from site redlines in any format. Marked-up PDFs, scanned prints and site photographs are all workable inputs. Drawings are returned in AutoCAD DWG with PDF issue copies, typically within 24 to 48 hours.
We work on a per-markup basis rather than an hourly rate, so the cost is known before the work starts — which makes it straightforward to price into a package at tender stage rather than absorbing it at the end.
More detail on our as-built drawing services and redline markup incorporation, or contact info@outsourcecad.com or +44 28 9009 8876 to discuss a live project.
