Conceptual view inside a kitchen sink base cabinet showing supply lines and a drain trapDesign concept

Behind the walls

The invisible work sets the limits on everything visible

Where water, waste, cable, and ductwork can reasonably go determines which layouts are practical. This page explains rough-in, the questions that must be settled before walls close, and where qualified trades take over.

Coordination

Decisions that must be locked before surfaces close

These are the items that are inexpensive to change on a drawing and expensive to change once tile is on the wall.

Rough-in coordination items

ItemWhy it is decided early
Sink and dishwasher positionDrainage fall and waste routing depend on the location, not just the supply.
Appliance modelsExact dimensions, connection type, and clearances differ between models; cabinetry is built to them.
Fuel or supply type at the rangeWhether the cooking appliance is electric or gas changes the connection, the surrounding detail, and who performs the work.
Outlet positionsCounter outlets, island supply, and appliance circuits should follow how you work, not a default spacing.
Under-cabinet lighting supplyCable must be in place before backsplash and cabinets close the wall.
Ventilation routeDuct path, length, and terminations shape hood effectiveness and noise.
Water treatment or filtered tapAn extra tap or under-sink unit needs space, supply, and sometimes a drilled counter hole.
Shut-offs and accessServiceable access to valves and connections saves considerable disruption later.

Scope boundaries

Where qualified trades take over

Kitchen coordination is about sequencing and planning. Regulated work is carried out by the appropriate qualified trades under the rules that apply locally.

Scope

Plumbing

Supply, drainage, venting, and gas connections where applicable are performed by qualified plumbers to the applicable code.

Scope

Electrical

Circuits, panels, device installation, and any required protective devices are performed by qualified electricians to the applicable code.

Scope

Permits and inspection

Whether permits and inspections are required depends on scope and jurisdiction. Confirm with the local building department for your address.

Walk the room and answer these

  • What plugs in on each stretch of counter, on a normal weekday?
  • Is the island going to carry a sink, a cooktop, or seating with device charging?
  • Do you know the exact model numbers of appliances you plan to keep or buy?
  • Where can a hood duct realistically run from the range position you want?
  • Are there existing pipe or cable runs that constrain wall changes?
  • Do you want isolating valves accessible without emptying a cabinet?

No claims made here

This page describes general coordination practice. It does not state code requirements for your property, does not claim any licence, certification, insurance, or warranty, and is not a substitute for advice from the qualified trades and local authority responsible for your project.

Questions

Plumbing and electrical FAQ

Why does moving a sink cost more than it looks?

Water supply is comparatively easy to reroute; drainage is not, because it depends on fall and on where the existing waste line runs. Moving a sink can mean opening the floor or building a raised platform to maintain that fall, which is a structural and finish question rather than a plumbing detail.

What is rough-in and why does the schedule pause there?

Rough-in is the stage where pipework, cable, and ventilation are installed while walls and floors are still open. Where permits and inspections apply, this stage is typically inspected before surfaces are closed. It is the last comfortable moment to change appliance positions or add an outlet.

How many outlets does a kitchen need?

More than most kitchens have, and in the places you actually work rather than evenly spaced. It is worth walking the counter and naming what will plug in where — kettle, toaster, mixer, charger — then adding to the plan. Circuit requirements for appliances are determined by a qualified electrician against the applicable code, not by a website.

Does the ventilation route matter?

Considerably. A hood works best when it can exhaust along a short, direct route. If the range sits on an interior wall, the duct path may be long or awkward, which affects both effectiveness and noise. Confirming a workable route before finalising the layout avoids disappointment later.

Who is responsible for permits and inspections?

Requirements depend on the scope and the local authority having jurisdiction. This site does not state what your project needs or claim any licence or certification. Confirm with the relevant local building department and the qualified trades performing the work.

Planning a kitchen project?

Write down your room measurements, what frustrates you about the current layout, and which parts you would keep. Contact details will be added before publication; until then the assistant answers informational questions.

See what to prepare