MEP Sleeve and Cutout Drawings: Fixing the Services Before the Concrete Is Poured

Why the sleeves come before the concrete

Every pipe, duct and cable in a building has to pass through a slab, a beam or a wall somewhere. If the opening is left in the formwork, it costs almost nothing. If it is forgotten, it has to be core-cut through hardened concrete later - slow, noisy, and risky wherever the reinforcement or a beam is in the way - and through a water tank wall or a basement retaining wall it can mean a leak for the life of the building.

A sleeve and cutout layout fixes every one of those openings on one drawing, checked against the structure, and is issued to site before each slab is poured. On the Ravet tower, a six-sheet set covered every sleeve and cutout through the first slab and the retaining walls, so the structure could be cast once.

What the drawing shows

A sleeve and cutout layout for one slab usually shows:

• Plumbing cutouts for the soil, waste, rain-water and supply pipes, with their sizes and positions from the grid
• Sleeves through the beams, with their diameter and invert level
• Sunk slabs under toilets, baths and kitchens, and the beams that must stay top-flush so the pipes can pass
• Electrical and low-voltage cutouts for the risers, meter rooms and cable routes
• Fire cutouts and sleeves for the hydrant and sprinkler pipes
• Ventilation and HVAC duct openings
• Openings in the retaining walls for the incoming power, water and earthing
• Sections showing the level of each opening where it matters

What we fixed before the first slab

The first slab over a basement or parking level carries the most openings, because every service in the building comes down through it. Some of the first slabs we have set out:

Beams, sunk slabs and toilets

Most clashes on site happen where a drain has to leave a toilet. The pipes need a sunk slab to fall inside the floor, and a beam in the way either has to be kept top-flush or given a sleeve at the right level. On the Ivory bungalow, the first-slab layout gave 100 mm sleeves through the beams and either a 200 mm sunk slab or a top-flush beam under every toilet, with plumbing cutouts of 600 x 300 and 1,420 x 900 mm; the second slab, a month later, had its own layout with 150 mm beam sleeves and the HVAC and electrical ducts.

On the Godoli project, the toilets were planned with 200 mm walls between back-to-back toilets, and raised by 250 mm where the pipes divert at ceiling level. On the Ashramshala at Shirur, the first and second slabs have 200 and 300 mm sunk areas for the toilets and baths, with the beams that must stay top-flush marked on the same drawing.

Retaining walls and tank walls

Openings in a basement retaining wall or a water tank wall cannot be cut later without risking a leak, so they are fixed with the wall. On the Ravet tower, the retaining wall has a 300 x 200 mm cutout for the earthing strips, 450 x 200 mm for the low-voltage cables and 750 x 200 mm for the transformer-to-LT-panel connection, and the underground tanks have a 17-sleeve chart giving every sleeve's size, flange type and level above the tank bottom. On the Bhosari commercial building, the tank sleeves - inlets, draw-in and draw-out, overflows, suctions and test lines - are scheduled with puddle-flange details.

Large openings for ducts and cables

Ventilation and power need the biggest openings, and they are the hardest to add later. On the Ravet tower, the basement exhaust fan of 28,000 cfm discharges through a 2,100 x 1,700 mm cutout. On the Mantra towers at Balewadi, each tower has a 300 x 900 mm slab cutout for the DG set cables, beside the busbar trunking in the electrical riser.

What the drawing catches

Setting out the openings is also when the services and the architecture are checked against each other for the first time, and it often changes the drawings. On the Warje project, the kitchen pipes of the four front flats were diverted to the far side so they stay out of sight, and the height of the upper ground floor was increased by 200 mm. On the Taloja school, the basement clear height went from 3.0 m to 3.2 m so the drains diverted at the basement ceiling could fall properly. On the Bhukum township, the cutouts were revised each time the architect's and the structural layouts changed, before the drawing was issued.

Checking the slab on site

A drawing only helps if the site follows it. On the Warje project, after issuing the first-slab layout in March 2026, we checked the slab on site against it in September 2026.

What to send

To prepare the sleeve and cutout layout for your next slab, we need:

• The structural drawings for the slab: the beam layout, sizes and levels
• The architectural plan for the floor above and the floor below
• The MEP layouts, if they are already drawn - or we draw them first
• The casting date of the slab, so the layout reaches site in time

Our sleeve and cutout work

We issue sleeve and cutout layouts as part of our MEP shop drawings and coordination, slab by slab, for residential towers, bungalows, schools and factories across Pune, and as part of the full MEPF design with the plumbing, electrical and fire fighting layouts. See MEP consultants in Pune, or send your drawings for a free project review.