Mike had everything lined up. Architect. Builder. A beautiful lot outside Bobcaygeon with a view of the lake. The excavator showed up on a Monday morning, ready to dig the foundation. By Monday afternoon, the builder was on the phone with the municipality, and the project was on hold.
Nobody had applied for a septic permit. And in Ontario, you don’t get a building permit without one.
Mike lost three weeks. His builder sat idle. The concrete crew moved on to another job. All because the septic system wasn’t part of the plan from day one.
If you’re building a new home in Ontario, this guide covers exactly how the new construction septic system process works, what it costs, and how to keep your build on schedule.
The Septic-First Rule in Ontario
Here’s what catches most people off guard. In Ontario, the septic system isn’t something you figure out after the house is framed. It’s something you figure out before you break ground.
Under Part 8 of the Ontario Building Code, any new home that won’t connect to municipal sewer needs a permitted on-site sewage system. And the municipality won’t issue your building permit until the septic permit is approved.
That means the septic design has to come first. Before the foundation. Before the framing. Before anything.
In the City of Kawartha Lakes, the Building Division handles both building permits and septic permits. They coordinate the two, and they won’t sign off on one without the other. The same applies whether you’re building in Lindsay, Fenelon Falls, or Coboconk.
This isn’t a suggestion. It’s a hard rule. The septic system design affects where you can place the house, the driveway, the well, and any outbuildings. Get it wrong, and you redesign the whole site plan.
For a full breakdown of permit requirements, check our septic permit guide.
Planning a new build in Kawartha Lakes? Call us at (705) 242-0330 before you finalize your site plan. We’ll make sure the septic system is accounted for from the start.
The Septic Installation Process for New Construction
Building a septic system for a new home follows six steps. Skip one, and you’ll pay for it later.
Step 1: Site Evaluation and Soil Testing
A qualified designer visits the property and evaluates the soil. This includes a percolation test (perc test) to measure drainage rates and a soil profile to check depth to bedrock and the water table.
The results determine everything. What type of system your lot can support. Where the leaching bed can go. How large it needs to be. If bedrock is shallow, you may need a raised bed or an advanced treatment unit, which changes your budget and timeline.
Step 2: System Design
Based on the site evaluation, the designer creates a full system plan. This includes tank size, bed dimensions, pipe layout, and all required setbacks from wells, water bodies, property lines, and the house itself.
The design must comply with Part 8 of the Ontario Building Code. For new homes, the system is sized based on the number of bedrooms. Our septic tank size guide explains how sizing works and what to expect.
Step 3: Septic Permit Application
The design package gets submitted to the municipality along with the permit application. In Kawartha Lakes, this goes to the Building Division. The application includes the system design, site evaluation, property survey, and the permit fee.
Review times vary. During busy building seasons, expect two to four weeks. During slower months, it can be faster. Either way, this is why you apply early.
Step 4: Coordination With Your Builder
Once the septic permit is approved, you can apply for your building permit. The two need to work together. The house location, the well location, and the septic bed location all have to meet setback requirements. Your builder and septic installer should be talking to each other before construction starts.
Step 5: Installation
The septic system is typically installed early in the construction process. The tank and distribution pipes go in while heavy equipment is already on-site. This saves money compared to bringing equipment back later.
In Ontario, septic installation must be done by a qualified person under the Ontario Building Code.
Step 6: Municipal Inspection and Backfill
Before the system gets covered with soil, a municipal inspector visits the site. They verify the installation matches the approved design. Tank depth, pipe grades, bed dimensions, aggregate depth.
Only after the inspector signs off can the system be backfilled. If the inspector finds a problem, it’s far cheaper to fix it before the soil goes back on.
System Options for New Builds
When you’re building from scratch, you’ve got more options than someone replacing an old system. Here are the most common choices for new construction in Ontario.
Conventional System (Tank and Leaching Bed) The standard. A septic tank separates solids, and the effluent flows by gravity to a leaching bed where soil provides final treatment. Works well on lots with good drainage and adequate space. This is the most affordable option and the easiest to maintain.
Raised Bed System If the water table is high or bedrock is close to the surface, a raised bed lifts the leaching area above the natural grade. Common around Kawartha Lakes where Canadian Shield rock sits close to the surface. Costs more than a conventional system, but it’s a proven solution for challenging lots.
Tertiary Treatment Unit For lots with tight constraints, poor soils, small footprints, or proximity to sensitive water bodies, an advanced treatment unit processes effluent to a higher standard before it reaches the soil. These systems use aerobic treatment, filters, or UV disinfection. They’re the most expensive option and require maintenance contracts, but they allow building on lots that wouldn’t otherwise support a septic system.
Pump System When the leaching bed sits uphill from the tank, a pump chamber sends effluent to the bed under pressure. This adds a pump and alarm to the system, but it gives more flexibility in bed placement.
Your designer will recommend the right system based on your soil test results and lot layout. Learn more about septic system rules in Kawartha Lakes to understand local requirements.
What It Costs
A new construction septic system in Ontario typically falls into these ranges:
- Conventional system: $15,000 to $25,000
- Raised bed system: $25,000 to $35,000
- Tertiary treatment unit: $30,000 to $50,000+
- Permit fees: $500 to $1,500 depending on the municipality
- Design and site evaluation: $2,000 to $4,000
Total cost for most new builds in Kawartha Lakes lands between $18,000 and $35,000.
A couple building near Fenelon Falls last year budgeted $20,000 for their septic system. The site evaluation came back showing shallow bedrock across their lot. They needed a raised bed, and the final cost was $31,000. They were frustrated, but glad they found out before pouring the foundation. Their designer adjusted the house placement to work with the bed location, and the build stayed on schedule.
Get your site evaluation done before you finalize your construction budget. Soil surprises are expensive when they come late.
For a detailed cost breakdown, see our septic system replacement cost guide. The pricing for new installations follows similar ranges.
Timeline Expectations
Here’s a realistic timeline for the septic portion of a new build in Ontario:
| Phase | Timeline |
|---|---|
| Site evaluation and soil testing | 1 to 2 weeks |
| System design | 1 to 2 weeks |
| Permit application and review | 2 to 4 weeks |
| Building permit coordination | 1 to 2 weeks |
| Installation | 2 to 5 days |
| Inspection and backfill | 1 to 3 days |
Total: 5 to 10 weeks from first site visit to approved installation.
Start the septic process at least three months before you plan to break ground. That gives you a buffer for soil surprises, permit delays, or design revisions.
During peak building season (April through October), permit review times stretch. Designers and installers book up fast. If you’re planning a spring or summer build, start the septic process in winter.
Common Mistakes That Delay Builds
We’ve seen every version of these. Here are the six mistakes that cost builders and homeowners the most time and money.
1. Treating the septic system as an afterthought. The house design comes first, and the septic gets squeezed into whatever space is left. This creates setback problems and sometimes forces a site redesign. Plan the septic and the house together.
2. Skipping the site evaluation before buying the lot. Not every lot can support a septic system. If you’re buying vacant land for a new build, get a site evaluation before you close. It’s a few thousand dollars that could save you from buying an unbuildable lot.
3. Underestimating the timeline. Builders who assume the septic permit will take a week end up losing a month. Build the full timeline into your project schedule from the start.
4. Not coordinating between the septic designer and the builder. The septic bed needs specific space, setbacks, and elevation. The house plan needs to account for all of that. When the designer and builder don’t talk, you get conflicts that delay both permits.
5. Hiring an unqualified installer. Ontario requires septic systems to be installed by qualified persons under the Building Code. Hiring someone without the right credentials means the municipality won’t approve the installation. You’ll tear it out and start over.
6. Ignoring local rules. Kawartha Lakes has specific requirements that go beyond the provincial code, especially for properties near lakes and waterways. Our guide to septic system rules in Kawartha Lakes covers what you need to know.
Don’t let your septic system hold up your build. Book a consultation or call (705) 242-0330 and we’ll get your new construction septic system planned, permitted, and installed on schedule.
Frequently Asked Questions
Do I need a septic permit before a building permit in Ontario?
Yes. In Ontario, the septic permit must be approved before the municipality will issue a building permit for a new home on a property without municipal sewer. The septic design determines house placement, so it has to come first. Our septic permit guide walks through the full application process.
How long does it take to install a septic system for a new build?
The physical installation takes two to five days for most systems. But the full process, from site evaluation to final inspection, takes five to ten weeks. The permit approval phase is usually the longest part. Starting early is the single best thing you can do for your construction timeline.
Can I install a septic system myself on my own property?
Ontario allows property owners to install their own septic systems under certain conditions, but you still need an approved design and a permit. The installation must pass a municipal inspection. For new construction, we strongly recommend using a licensed installer. A failed inspection at this stage delays your entire build.
What size septic tank do I need for a new home?
Tank size is based on the number of bedrooms. Under the Ontario Building Code, a one to three bedroom home requires a minimum 3,600-litre (approximately 800-gallon) tank. Four bedrooms require 4,500 litres. Five bedrooms require 5,700 litres. Your designer will specify the exact size. Check our septic tank size guide for a complete breakdown.
Get Your New Build Started Right
Your new construction septic system isn’t just a box to check on the permit application. It’s the foundation of your property’s wastewater management for the next 25 to 30 years. Get it right from the start, and you won’t think about it again for decades. Get it wrong, and you’ll be dealing with problems before the paint is dry.
Start with the septic. Hire a qualified designer. Get the site evaluation done early. Coordinate with your builder. And give yourself enough lead time for permits.
We handle new construction septic systems across Kawartha Lakes, including Lindsay, Bobcaygeon, Fenelon Falls, and Coboconk. If you’re building a new home, we’ll walk you through the entire process. Regular maintenance after installation keeps your system running for decades.
Call (705) 242-0330 or book online to start planning your new construction septic system today.