Building services · Electrical · Plumbing · HVAC

MEP drafting software online — services layouts drawn on a real plan

CivilOS is free MEP drafting software that runs in a browser tab. It is for the services draughtsman, the site electrical or plumbing engineer and the junior MEP consultant who has an architectural plan in hand and has to produce a clean, layered, plottable services drawing — a lighting and power layout, a water supply and drainage layout, a duct or sprinkler layout — without a desktop licence. Be clear about the boundary before you start: CivilOS draws services. It does not size them.

What you can do

Switching IndoCAD from Civil to Electrical or Mechanical mode swaps in that discipline's symbol palette and its layer names, so a services drawing is built from real objects instead of being faked with loose lines and text. Each symbol is one definition — what you see, what you snap to and what lands in the DXF cannot drift apart.

Feature	What it does	Export
Discipline mode	Civil, Electrical or Mechanical — changes the symbol palette and the layers new objects file themselves onto	DXF layers
73 MEP symbols	35 electrical (points, switches, sockets, DB, MCB, isolator, changeover, UPS, DG, earthing, detection, data, CCTV, solar PV) and 38 mechanical (valves, fittings, gauges, pumps, ducts, diffusers, grilles, VAV, AHU, FCU, chiller, cooling tower, sprinkler, hydrant)	R12 DXF
Run symbols	Conduit, cable tray, pipe, double-line pipe, duct and cove lighting are drawn point-to-point; the graphic stretches with the run	R12 DXF
Discipline layers	E-POWR, E-LITE, E-COND, E-COMM, E-EART, E-FIRE, P-PIPE, P-SANR, M-PIPE, M-PIPE-VALV, M-HVAC, M-EQPM, F-PROT — freeze one service to check another	Named DXF layers
Block library	200+ blocks with dedicated Sanitary, Electrical, Services and Fire & Safety categories — WCs, basins, sinks, tanks, panels, extinguishers, hose reels	R12 DXF
Precision drafting	Object snaps (endpoint, midpoint, centre, intersection, perpendicular, nearest), typed absolute, relative `@dx,dy` and polar `@d<angle` coordinates, ortho, trim, extend, offset, array	—
Annotation	Aligned, linear, angular, radius and diameter dimensions, leaders, notes and tags on their own annotation layers	R12 DXF
Import	Open the architect's DXF or DWG read-only, snap to its walls and openings, and draw the services over it	—
Sheet plotting	A0–A5 and ARCH sizes at a chosen scale, with title block, north dial and scale bar	Print / save as PDF
Counts	Placed blocks can be counted into a schedule table read straight from the drawing, not retyped	CSV, on-sheet table

How it fits an Indian services drawing

Three things make a services drawing usable on an Indian site, and all three are about discipline rather than cleverness. The first is the layer convention. CivilOS uses AIA/NCS discipline-major-minor names, which is what a consultant's AutoCAD and every DWG you receive already use, so a drawing exported from here lands in their file with layers they recognise. Nothing arrives on Layer 0, because a light point knows it is a light point and files itself on E-LITE.

The second is symbols that a contractor reads without a legend argument. The electrical set follows IS 732 and common Indian practice — the crossed circle for a light point, S for a one-way switch, the half-circle with a stem for a socket outlet, 5 A and 15 A called out on the symbol itself, DB and MCB boxed and lettered. The mechanical set uses the standard valve, fitting and terminal graphics that a plumbing or HVAC contractor has seen on every shop drawing.

The third is the sheet. A services layout is issued, not just drawn: it needs a border, a title block that names the project and the revision, a north arrow and a scale bar that survives photocopying. Plotting in CivilOS puts the drawing on real paper sizes at a real scale, so the print can be measured. If the services layout later feeds a quantity — points, runs, fittings — the drawing itself is the source, and the National Building Code Part 8 provisions your consultant is working to stay where they belong: in the design, not hidden inside a black-box calculator.

How to draw a services layout in CivilOS

Open the plan. Import the architect's DXF or DWG. It comes in read-only, with its own layers, so you can fade or freeze the architecture while you work.
Switch discipline. Set IndoCAD to Electrical or Mechanical. The palette changes and every new object starts filing itself onto the right service layer.
Place the points. Drop light points, fans, switches, sockets, detectors, diffusers or sanitary fittings, snapping to wall faces and room centres. Rotate and scale each symbol as the plan needs.
Draw the runs. Pick two points for a conduit, cable tray, pipe or duct run — the graphic stretches to the run so the drawing shows a route, not a decorated line.
Tag and dimension. Add circuit references, sizes and levels as text and leaders, and dimension anything a contractor must set out — a DB position, a floor trap, a riser location.
Sort the layers. Freeze services one by one to check each in isolation, then turn on the combination you want to issue — power only, lighting only, or the coordinated set.
Plot the sheet. Choose the paper size and scale, fill in the title block, place the north dial and scale bar, and check the drawing fits the printable area before you commit.
Issue it. Print or save the sheet as a PDF for the site copy, and export R12 DXF for the consultant who will open it in their own CAD.

What CivilOS does not do

No sizing or load calculation of any kind. No connected-load or demand-factor calculation, no cable, breaker or earthing sizing, no pipe or duct sizing, no pressure drop, no heat-load or ventilation-rate computation. You bring the sizes; CivilOS draws them.
No clash detection and no 3D services model. Services are drafted in 2D. There is no Navisworks-type coordination, no point clouds and no 4D/5D simulation.
No paper-space layouts or viewports, no XREF and no LISP scripting. Plotting is a direct sheet-and-scale plot, and there is no annotative text scaling.
DXF write only. CivilOS reads DWG but cannot write it. Drawings leave as R12 DXF.
No rendering engine. Output is line work on a sheet, not a visualisation.
It does not sign your drawing. A services layout affects safety. A qualified MEP engineer must review, correct and approve it before anything is installed.

Where a browser MEP tool actually fits

Desktop MEP packages in this category are typically bought for three things a drafting tool does not attempt: engineering calculation (loads, sizes, pressure drops), a coordinated 3D services model with clash checking, and deep integration with a firm's document control. On a large hospital or a mall, those are the reasons the licence exists, and a browser tool is not a substitute for them.

A very large share of everyday services drawing is not that. It is a lighting and power layout for a floor, a plumbing layout for a residential block, a duct route on a shop drawing, an as-built markup of what the electrician actually ran, a sprinkler layout for a small warehouse. That work needs correct symbols, correct layers, snapping that lands on the wall face, and a sheet that prints to scale — and it is often being done by someone who is on site, on a borrowed laptop, or waiting on a licence that has not been approved. CivilOS is built for exactly that gap: open the plan, draw the services properly, hand over a DXF the consultant can use. When the job genuinely needs load calculations or a coordinated model, use the tool built for that, and let CivilOS carry the drafting.

Open IndoCAD free → electrical and mechanical symbols, service layers, DXF export

Frequently asked questions

Does CivilOS size cables, ducts or pipes?
No. CivilOS has no load calculation, no cable or breaker sizing, no duct or pipe sizing and no pressure-drop or heat-load engine. It is a drafting tool: you decide the sizes and CivilOS draws, labels, layers and plots them. Sizing must come from your own calculations or a dedicated engineering package.

What MEP symbols does CivilOS include?
73 symbols in total — 35 electrical (light and tube light points, ceiling and exhaust fans, one-way and two-way switches, 5 A / 15 A / 6-16 A sockets, DB, MCB, isolator, changeover, UPS, DG set, earth point, lightning arrester, conduit, cable tray, riser, TV/data, CCTV, Wi-Fi AP, intercom, smoke and heat detectors, call point, sounder, exit and emergency lights, solar PV) and 38 mechanical (single and double line pipe, gate, ball, check, globe, butterfly and relief valves, elbow, tee, reducer, strainer, flange, bellows, hanger, pump, gauges, flow meter, duct, diffuser, grille, damper, VAV, AHU, FCU, chiller, cooling tower, sprinkler head, hydrant, plus machine elements).

Can I open the architect's DWG and draw services over it?
Yes. CivilOS imports DXF and DWG for reading, so you can open the received architectural plan, snap to its walls and openings, and draw the services layout on top. Import is read-only — the drawing you author is exported as R12 DXF, which opens in AutoCAD, BricsCAD, DraftSight, ZWCAD and similar.

Which layers do MEP objects land on?
Every symbol files itself onto its own discipline layer using AIA/NCS names, so nothing lands on Layer 0: E-POWR power, E-LITE lighting, E-COND conduit and tray, E-COMM data and security, E-EART earthing, E-FIRE detection, P-PIPE plumbing, P-SANR sanitary fittings, M-PIPE piping, M-PIPE-VALV valves, M-HVAC ducts and terminals, M-EQPM plant, M-FIRE and F-PROT fire protection. You can freeze one service and check another.

Does CivilOS do clash detection between services and structure?
No. There is no clash detection, no Navisworks-style coordination and no 3D services model. Services are drafted in 2D on a plan. Coordination between disciplines still has to be done by overlaying drawings and by the judgement of the engineer.

Can I plot a services drawing on a proper titled sheet?
Yes. Plot to A0, A1, A2, A3, A4, A5 or ARCH sheet sizes at a chosen scale, with a title block, a north dial and a scale bar. The sheet prints from the browser, so you can save it as a PDF for issue or print it directly to a plotter.

Is it really free, and does it need installation?
It is free and runs entirely in the browser — nothing to install, no licence key, no dongle. It can be installed as a PWA so it opens like an app and works offline for drafting. The optional AI assistant is subject to fair-use limits; the drafting tools themselves are not.

Drafting tool, not a design tool. Every size, circuit, route and capacity shown on a CivilOS drawing comes from you. A qualified MEP engineer must review and approve the layout before it is built.