The short answer
Yes, you can put a sink, a hose bib or a floor drain in a detached garage in Edmonton. Two things change the moment you do. You lose the small-building permit exemption, because that exemption only applies to a structure that is not connected to electricity, plumbing or gas. And the plumbing has to be in the ground before the slab goes down, because afterwards the only way in is a saw and a patch.
So the decision is not really “do I want a sink.” It is “am I deciding this before or after the concrete truck comes.”
What the permits actually are
The City’s position on accessory buildings is straightforward. Most of them need both a development permit and a building permit. A structure under 10 square metres — about 108 square feet — can be exempt, but one of the exemption conditions is that it is not connected to electricity, plumbing or gas lines.
Read that twice if you were planning a small serviced shop. A 100-square-foot shed with no services may be exempt. The same shed with a sink is not.
| What you’re building | Development permit | Building permit | Plumbing permit |
|---|---|---|---|
| Garage or shed under 10 m², no services | Usually exempt | Usually exempt | No |
| Garage or shed under 10 m², with water or a drain | Required | Required | Required |
| Typical double garage | Required | Required | Only if plumbed |
| Adding a sink to an existing garage | Check with the City | Check with the City | Required |
One more number worth knowing before you draw anything: for a detached garage, the City requires 1.2 metres — four feet — from the garage door to the property line next to the alley. In the older alley neighbourhoods where most of these projects happen, Delton, Calder, Dovercourt, that four feet is often the constraint that sets the whole footprint.
The plumbing permit, and who is allowed to pull it
A plumbing permit is needed when you install or alter plumbing equipment. It is not needed to swap a fixture that stays in the same place. Sinks, water piping, drains, toilets, bathtubs and backwater valves are all on the City’s list of work that needs one.
Who may apply matters:
- Homeowner permit. You must own and occupy the single detached house, and you must do the work yourself.
- Contractor permit. Contractors must be licensed with the City of Edmonton.
The fee for other types of residential plumbing is $120 per address or unit, plus a minimum $4.80 safety codes fee. That is one of the cheaper line items on this whole project, which is exactly why skipping it is such a bad trade — an unpermitted plumbing alteration is the kind of thing that surfaces when you sell.
An inspection follows. Once the work reaches the right stage you request a Safety Codes inspector, and that inspection happens while the trench is open. Not after it is backfilled, and definitely not after it is under four inches of concrete.
How the water and the drain actually get there
EPCOR’s connection guide gives a serviced lot with an unserviced new building two routes, and the cost difference between them is large.
Route one — a new service connection. You apply for a new water or sewer service connection to an existing EPCOR main. EPCOR constructs the line from its mainline to your property line, at your cost, and a new connection comes with a new meter and meter setting. Only EPCOR crews and authorized contractors may install water and sewer service lines inside public property or a utility right-of-way.
Route two — extend from the house. You extend an existing private service line to reach the new building. This is the cheaper route for most backyard garages, and it is what most Edmonton homeowners end up doing.
There is one hard rule on route two, and EPCOR states it without wiggle room: the customer shall not connect to a private service line before the water meter under any circumstances. Your garage line comes off the house plumbing on the downstream side of the meter. Everything you use out there is measured.
A few other things worth planning around:
- A servicing plan with a utility locate sheet is part of the application. Get the locate done before anyone breaks ground, which matters more than usual in a backyard where you may also be crossing a gas line to the house.
- New or renewed private water service lines of 40 mm — about an inch and a half — or larger have to be flushed, disinfected and bacteriologically tested by an accredited lab before the water is turned on. Residential garage lines are usually smaller than this, but if your plan calls for a larger line, that testing is a real cost and a real delay.
- Quoted construction charges are not open-ended. EPCOR states they are subject to revision, so a price you were given long before you actually dig may not be the price you pay.
- If you ever remove a serviced building, unused sewer services must be cut and capped at the property line by the owner. That is a demolition cost people forget.
Why this has to happen before the pour
Here is the sequence that works:
- Permits in hand — development, building, plumbing, and electrical or gas if applicable.
- Excavate, form, and place the base.
- Rough in the water line, the drain line, and any sleeves for electrical or gas.
- Inspection, with the trench open.
- Pour the slab.
Here is the sequence that costs money:
- Pour the slab.
- Decide you want a sink.
- Saw-cut the slab, break out a strip, dig, plumb, inspect, backfill.
- Patch the strip.
The patch never disappears. A saw cut and a new pour leave a visible seam and a colour difference that no amount of sealing hides, and the two slabs move independently from the first winter onward.
Even a sleeve is worth it. If you are not sure about plumbing but you might want it later, running an empty conduit under the slab before the pour costs very little and saves the whole cut-and-patch exercise. Same logic for a conduit for power out to the garage.
What this costs
Using the 2026 Edmonton pricing on our concrete cost calculator page:
| Item | Size | Typical range |
|---|---|---|
| Double garage pad | 24 ft x 24 ft = 576 sq ft | $4,608 to $6,912 |
| Saw-cut and patch a strip later | 3 ft x 20 ft = 60 sq ft | $600 to $900, plus cutting and disposal |
| Plumbing permit | Per address | $120 plus a minimum $4.80 safety codes fee |
Take the pad. At 576 square feet and four inches thick, that is roughly 7.1 cubic yards of concrete. At Edmonton ready-mix pricing the concrete itself is about $1,280 to $1,780 of a $4,608 to $6,912 job.
That ratio is the single most useful thing to understand about any concrete quote. The concrete is roughly a quarter of the bill. The rest is excavation, base preparation, forming, placing, finishing and cleanup — labour and equipment, not material. Which is why adding a drain to a pour you are already doing is cheap, and why cutting into a finished slab is not. In the second case you are paying for mobilization, cutting, breakout, disposal and finishing all over again, on 60 square feet instead of 576.
A rough-in added during the original pour is usually a few hundred dollars of trenching and pipe. The same rough-in a year later can cost more than the plumbing itself.
Drainage, frost and the Edmonton winter
Two local realities worth building around.
A garage floor drain needs somewhere to go, and that somewhere is regulated. This is not a matter of running a pipe to the lawn. Where a garage drain is permitted to discharge, and what has to be installed ahead of it, is part of the plumbing permit conversation. Ask before you design the slope of the floor, because the drain location sets the slope and the slope is cast in.
Frost moves things. Edmonton gives concrete a long winter and repeated freeze and thaw on either side of it. A pad with a trench cut through it has a weak line down the middle, and that is where frost movement shows up first. A pad poured over a properly compacted base with the services already in place does not have that line. Our pages on concrete pads and concrete foundations cover how the base is built under each.
If the garage sits off an alley, the approach matters too — the driveway or alley apron takes the same truck traffic as the pad. Our driveway pages and the longer driveway cost and design guide cover that side.
If you are outside Edmonton
Permit rules and fees are municipal. Sherwood Park, St. Albert, Spruce Grove, Leduc, Beaumont, Fort Saskatchewan and Stony Plain each run their own process, with their own fees, thresholds and setbacks, so do not assume the 10 square metre exemption, the four-foot alley setback or the $120 permit fee applies where you live. Servicing varies too — the EPCOR rules described here are for its Edmonton service area.
Where this page stops
This page covers running water and drainage to a detached garage in Edmonton: which permits apply, who may pull them, the two routes for getting services to the building, the order of work, and what the pad and a later patch cost.
It does not cover utility right-of-way and easement restrictions on where you may build, lot grading approval, the monthly drainage charge on your utility bill, who pays for public sidewalk repair, street occupancy permits for the concrete truck, or liability for falls on your property — each of those is its own page. It is also not a design or plumbing specification. Your plumber, the City and EPCOR have the final word on what gets approved.
FAQ
Do I need a permit for a garage in Edmonton if it has a sink? Yes. The permit exemption for small accessory buildings requires that the structure not be connected to electricity, plumbing or gas. Adding a sink removes the exemption, so you need a development permit, a building permit and a plumbing permit.
What does a plumbing permit cost in Edmonton? For other types of residential plumbing, the City lists $120 per address or unit plus a minimum $4.80 safety codes fee. A homeowner permit requires that you own and occupy the single detached house and do the work yourself; contractors must be licensed with the City.
Can I just run a water line from the house to the garage? Usually yes. EPCOR allows a customer to extend an existing private service line to serve a new building, and that is the cheaper route. The firm rule is that you may not connect to a private service line before the water meter under any circumstances.
When do the pipes have to be in the ground? Before the slab is poured, with the inspection done while the trench is open. After the pour, the only route in is a saw cut and a patch, which leaves a permanent seam and costs far more per square foot.
What if I am not sure yet? Run an empty conduit under the slab before the pour. It costs very little next to the pad itself and it preserves the option.
Does a garage floor drain need approval? Yes, and where it is allowed to discharge is part of the plumbing permit conversation. Settle it before the floor slope is designed, because the drain location sets the slope and the slope is cast into the slab.
Get a number on it
Tell us the footprint, whether the garage is getting water, a drain or both, and whether it sits off an alley. We will come back with a range for the pad and the rough-in trenching, and we will say plainly if the better move is a conduit now and plumbing later.
If the permits are not sorted yet, say so. It is easier to schedule a pour around a permit than a saw cut around a finished floor.
Sources: Detached Garage, Shed, Gazebo — City of Edmonton · Plumbing Permits — Residential, City of Edmonton · Drainage and Water Customer Connection Guide, EPCOR · Service Connections FAQ, EPCOR
