Concrete Doorway Opening: Planning, Cutting and Framing

A concrete doorway opening is a structural change, not a cutting job. The saw cut takes hours. The planning that comes first (permit, engineer’s design, scanning, lintel and finishing) decides whether the opening is safe, legal and square. This guide walks you through that sequence for walls in Melbourne and the rest of Victoria, so you know what to ask for and what to expect from the contractor you hire.

TL;DR

• In Victoria, a new door or a change to the width or height of an existing door frame almost always needs a building permit. Get it before work starts.
• Measure the clear opening, not the door leaf. New homes under the National Construction Code need an 820 mm clear width for key internal doorways.
• Scan the wall for rebar, conduit and services before any blade touches it. Never rely on drawings alone.
• The lintel (header) goes in before the full opening is cut, so the wall above is never unsupported.
• Wet cutting or dust extraction is part of the job, not an extra.

Table of Contents

• What a concrete doorway opening involves
• Do you need a permit in Victoria?
• Measuring the opening correctly
• Scan before you cut
• Lintels, headers and the order of work
• Choosing the cutting method
• Dust, water and safety on site
• Framing, finishing and the door itself
• Our view: the cut is the easy part
• What a doorway cut costs
• Getting the opening cut
• FAQ
• Sources

What a concrete doorway opening involves

An opening in a concrete or concrete block wall removes a section of material that may be carrying load from the floors, roof or wall above. That load has to be redirected around the opening and down into the wall on either side. Whether you are connecting two rooms, adding a basement walkout, opening a garage to an extension or creating a new entry to a warehouse bay, the same four questions apply:

1. Is the wall load-bearing, and what is above it?
2. What is inside it (reinforcement, conduit, pipes, post-tensioned cables)?
3. What size must the finished opening be, once framing and finishes are in?
4. Who approves the work, and who is licensed to do it?

The rest of this article answers those in order.

Do you need a permit in Victoria?

In most cases, yes. Victorian council guidance says you need a building permit if you are installing a new door or changing the width or height of an existing door frame. The reason is that the work alters the structural soundness of the building or affects essential safety measures. The permit requirement sits under the Building Act 1993 and the Building Regulations 2018. The main exception is replacing a door with a similar one without structural change, which is not what a new opening involves.

Councils make the same point more broadly: a permit must be in place before works commence for most alterations. In practice that means:

• Engage a structural engineer for any load-bearing wall, tilt-panel, retaining wall or foundation wall. The engineer specifies the lintel or steel beam, the bearing length and any propping.
• Give the permit documents to a registered building surveyor, who issues the permit and inspects stages of the work.
• Book your cutting contractor only once the approved design is in hand, so the saw cuts match the drawings.

If you are a property manager or facility manager, check lease conditions and any owners corporation rules as well. Planning overlays and heritage controls can apply separately from the building permit, so ask your local council.

Measuring the opening correctly

Most mistakes with concrete openings come from measuring the door instead of the space the door needs. Concrete cannot be added back easily, so the cut should be set out from the finished dimensions and worked backwards.

Start with the clear opening

For new homes and apartments, the National Construction Code’s Livable Housing Design Standard requires internal doorways on the main access paths to have a minimum clear opening width of 820 mm. A single swinging door with an 820 mm clear width can generally be achieved with an 870 mm door leaf. The same standard calls for thresholds that are level, or have a lip of no more than 5 mm if rounded or bevelled, or a ramp no steeper than 1:8. It also expects connected corridors to be at least 1000 mm wide. Whether the standard applies to your project depends on the building type and whether the doorway is on a path to the rooms it covers, so confirm with your designer or surveyor.

Work out the rough opening

The rough opening is the hole in the wall. It has to be larger than the clear opening to allow for:

• The door frame and jambs (timber, steel or aluminium)
• Packing and fixing tolerance around the frame
• Any lining, render or tiling returned into the reveal
• The lintel or beam depth above the head, which is set by the engineer, not by the door

A practical approach is to list every layer on each side and add them to the clear width, then do the same for height. Check the floor finish too. If you are tiling or laying timber later, measure to the finished floor level so the door does not end up short or dragging.

Check the wall thickness

Concrete walls vary: 100 to 200 mm in many residential and tilt-up applications, thicker in foundation walls and some commercial structures. Wall thickness determines which cutting method is practical, which is covered below. Measure it at an existing opening, a penetration or the wall end, not by guessing.

Scan before you cut

Never assume the wall is plain unreinforced concrete. Even residential walls can contain rebar, post-tensioned tendons or electrical conduit. Professional cutters scan every saw line or core position with ground penetrating radar (GPR) and cable-avoidance tools. That protects people from live services, and it protects the diamond blades from unexpected steel.

Two checks belong together:

1. A Before You Dig Australia (BYDA) search for external or underground services near the wall.
2. On-site scanning of the wall itself, because as-built conditions often differ from the plans. Industry safety requirements treat BYDA plus on-site scanning as the baseline before structural penetrations, and warn against relying on drawings alone.

Scanning results go to the engineer. If the scan finds heavy reinforcement or tendons in the planned line, the opening position or the cutting method may change. Better to learn that on a scan than mid-cut.

Lintels, headers and the order of work

The saw cut is the most visible part of the project, but the real engineering is at the head of the opening. A header carries the load from the wall above down to the jambs. In concrete and masonry it is typically a steel beam set into grouted pockets or a reinforced concrete lintel poured in place. Shortcuts here lead to cracking, doors that stick and failed inspections.

The sequence matters

The safe order is to form the lintel pocket and install the lintel first, then cut the full opening below it. Reversing that leaves the wall above temporarily unsupported, which can cause cracking, dropping or collapse. The lintel also needs enough bearing on the wall at each side to spread the load properly. Your engineer sets that length.

Watch for the bond beam

In concrete block (CMU) walls, the top course is often a grouted bond beam that ties the wall together. Cutting through it without knowing what sits above and without shoring can let the wall above shift. Professionals recommend identifying the bond beam before marking any cuts. If your opening reaches that course, the engineer needs to see it.

Typical order of work

1. Engineer’s design and building permit.
2. Scanning and service location; mark the opening on the wall.
3. Install temporary propping where the engineer specifies.
4. Cut and form the lintel pockets; install the lintel or beam.
5. Cut the opening with the agreed method, removing the concrete in sections.
6. Core out corners if the design calls for over-cut-free corners.
7. Clean up slurry and dust, then hand over for framing and finishing.

Choosing the cutting method

Different walls call for different equipment. The method affects accuracy, noise, dust and how the offcut pieces come out.

For most doorway openings through reinforced concrete walls, wall sawing gives the cleanest result because the saw runs on a rail fixed to the wall. That means straight lines, square corners and consistent edges, which makes framing the door much easier. For very thick or restricted sections, wire sawing is the alternative. Where noise, vibration or access are concerns, ask about low-vibration methods. Cutting also avoids the impact shock that a jackhammer sends through the structure, so the surrounding wall stays intact.

If the offcut is heavy, tell your contractor how it must come out. A section of 200 mm concrete weighs a lot, and the plan for lifting and removing it (cut into smaller pieces, or slid out on a rail) belongs in the method statement. Our concrete removal service covers breaking down and taking the material away.

Dust, water and safety on site

Cutting concrete releases respirable crystalline silica, which can cause silicosis when workers breathe it over time. The best control is wet cutting, where water suppresses dust at the blade. If you have to cut dry, the dust must be captured with M-Class extraction rather than left to settle. We explain the difference in more detail in our guide on wet versus dry cutting in Australia, and on our page about dustless concrete cutting in Melbourne.

For homeowners and occupiers, this has practical consequences:

• Ask how slurry will be contained and removed, particularly indoors.
• Seal doorways and vents to rooms you are not working in, and cover flooring.
• Keep children, pets and anyone with respiratory conditions out of the work area.
• Expect a written safe work method statement (SWMS) from a professional contractor before work begins.

Exposure limits for silica are changing in Australia, with a transition from workplace exposure standards to workplace exposure limits. Contractors should be working to the current requirements of the regulator in their state, so ask which standard the job is planned to.

Framing, finishing and the door itself

Once the opening is cut, the work shifts to the carpenter, builder or door installer. A few things to settle early.

Frames and facing

The cut edges of concrete are rough and rarely perfectly plumb, so frames are fixed with packers and shims and the gap is sealed. In block walls, one common option is to face the opening with treated timber that sits close to the wall width, so the frame has something solid to fix to. Steel frames can be anchored directly into the concrete with masonry anchors. Check that fixings are set away from the edge, because anchors placed too close can spall the concrete.

Fire-rated and commercial doors

If the opening is in a fire-separating wall, in a plant room or in a commercial or industrial building, the door and frame may need a fire rating. That means a certified door set, not an ordinary timber frame. Suppliers who make fire-rated steel doors and hollow metal frames, such as this manufacturer of fire-rated steel doors and commercial door hardware, show the range of products and certifications involved, though you should check Australian standards and your surveyor’s requirements before choosing a product.

Thresholds and floor levels

A threshold that sits proud of the floor is a tripping hazard, and a common reason people want to cut the slab below a door. If the floor level changes, the engineer needs to approve any cutting of footings or slab edges. Where accessibility matters, design to the level threshold or ramp limits in the Livable Housing Design Standard from the start.

Outdoor openings and archways

External openings, such as a side entry to a garage, a gate in a boundary wall or a walkout from a basement, add drainage, waterproofing and weather sealing to the list. A new external opening in a retaining or foundation wall needs special care because soil pressure acts on the wall. Archways are also possible, because a curved head is cut by drilling a series of cores and sawing between them, but the arch needs its own structural design and often a steel support behind the finish.

Our view: the cut is the easy part

We cut openings in concrete walls across Melbourne and Victoria, for homeowners, builders, property managers and industrial sites. The pattern we see is consistent: the jobs that go smoothly are the ones where the engineer’s drawing, the permit and the scan results are in hand before we set up.

Three things we ask every client:

• Has the wall been scanned? We scan as part of the job, because drawings do not always match what was built.
• What is the lintel detail and who supplies it? If the beam arrives late, the cutting waits, and rushing the support is never acceptable.
• Where does the dust and water go? We plan for wet cutting or extraction, and for slurry removal, before we start.

Our operators are licensed and qualified, we work to OH&S safety standards, and we handle everything from small domestic tasks to large construction projects. A door opening is usually a modest job for us, but we treat it with the same process as a commercial one: assess, scan, plan, cut, clean up.

— MYBMC

What a doorway cut costs

The price depends on wall thickness, reinforcement, access, the opening size, whether the work is inside or outside, and how the concrete must be removed. Our published range for concrete cutting is $450 to $5,000 per job, and we quote each project after we understand the wall. Remember that cutting is one line in the budget. Engineer’s fees, the building permit, lintel supply, framing, the door, making good and painting sit alongside it.

To keep the quote accurate, give the contractor:

• Photos of both sides of the wall
• The wall thickness and material (poured concrete, block, tilt panel)
• The desired opening size and position
• The engineer’s drawing, if you have it
• Access details: stairs, tight lanes, upper floors

Getting the opening cut

If you have an engineer’s design and a permit, or you need help working out what the wall needs, we can scan, cut and remove the concrete. Our wall sawing service is built for doorway openings, and the main Vic Sawing & Drilling site lists concrete cutting, concrete scanning and robotic demolition for larger jobs. We work across Melbourne, including Richmond, Werribee and Sunbury, and regional Victoria. Ask for a free quote and we will tell you plainly what the job involves.

FAQ

Can I cut a doorway in a load-bearing concrete wall myself?

We do not recommend it. The wall carries load, so the opening needs an engineer’s design, a lintel and usually a building permit. Cutting also needs scanning, propping and silica controls. Hire licensed operators with the right saws and extraction.

Do I need a permit to widen an existing door opening?

In Victoria, changing the width or height of an existing door frame generally requires a building permit. Check with your council or a registered building surveyor before you book the work.

How wide should the opening be?

For new homes under the National Construction Code, key internal doorways need an 820 mm clear width, usually an 870 mm door leaf. The rough opening must be larger to fit the frame and packing, so set it out with your builder.

What if there is steel in the wall?

Most structural concrete has rebar, and diamond blades and wire are designed to cut through it. What matters is knowing where it is. Scanning shows the layout so the engineer and cutter can plan around tendons, conduit and heavy bars.

Is cutting concrete messy?

Wet cutting produces slurry, but it keeps dust down and it can be contained and removed. Dust extraction is the alternative where water is not suitable. Either way, ask your contractor how they will protect the area.

Sources

• Do I Need a Building Permit? Hume City Council
• When a building permit is required, City of Greater Geelong
• Part 3 Internal doors and corridors, ABCB
• Designing livable and accessible bathrooms, KBDI
• Cutting a Doorway in a Foundation Wall
• Cutting a Door Opening in a Concrete Wall Safely and to Code
• Core Drilling for Construction Contractors
• HSEQ Requirements, Ertech Group

Recommended

• Concrete Cutting: Guide to Cutting A Door Into A Concrete Wall