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What Does “In-House Solar Engineering” Actually Mean?
In-house solar engineering is the practice of employing the people who design, calculate, and stamp your solar projects directly, rather than sending that work to an external engineering firm. That team typically includes PV system designers who lay out arrays and run production estimates, electrical engineers who size conductors and produce one-line diagrams, and a licensed Professional Engineer, or P.Eng, who reviews and stamps the final structural and electrical drawings before they go to the authority having jurisdiction, or AHJ.
This is a distinct function from sales design or installation planning. A sales rep sketching panel layout in a proposal tool is not doing engineering. Engineering is the step where someone with a licence takes legal responsibility for the load calculations, the racking attachment method, and the electrical protection scheme working as claimed. In Canada, that stamp carries weight with municipal building departments, provincial electrical safety authorities, and the local distribution utility reviewing your interconnection application.
Every solar installer eventually asks the same question: keep paying a third party to stamp your drawings, or bring engineering in-house? In-house solar engineering means employing your own PV designers and licensed engineers instead of contracting that work out project by project. The right answer looks completely different for a five-person residential crew in Alberta than it does for a commercial EPC closing forty projects a year in Ontario, and this guide walks through exactly why.
In-House Solar Engineering vs. Outsourcing: What’s the Real Difference?
Most installers don’t choose between “good engineering” and “bad engineering.” They choose between two different operating models, and each comes with trade-offs that only show up once volume changes. Both deliver the same stamped drawings — the difference is how the work gets staffed, scheduled, and paid for.
| Factor | In-House Team | Outsourced Partner |
| Upfront cost | High — salaries, benefits, software, E&O insurance for a P.Eng | Low — pay per project or per plan set |
| Turnaround during a slow month | You still pay full salaries | Costs drop with volume |
| Turnaround during a busy month | Limited by headcount and can bottleneck | Scales by adding project load to the partner |
| Provincial licensing coverage | Usually one or two provinces where your P.Eng is registered | Firms often carry reciprocal licensing across multiple provinces |
| Control over process and revisions | Direct, same-day communication | Depends on the partner’s responsiveness and SLA |
| Best fit | High, steady commercial volume in one core region | Variable volume, multi-province work, or growing installers |
A useful rule of thumb: if your engineering workload is steady enough to keep one full-time P.Eng busy 48 weeks a year, in-house starts to pencil out. Below that, you’re paying for idle capacity.
What Does an In-House Solar Engineering Team Actually Do, Day to Day?
The title sounds broad, but the work breaks down into three concrete deliverables that every commercial or residential project needs before it can be installed and connected to the grid.
PE-Stamped Structural and Electrical Drawings
Structural engineering confirms the roof, ground mount, or carport can carry the added dead load, plus whatever snow and wind load applies for that site under the applicable provincial building code. Electrical engineering covers string sizing, overcurrent protection, conductor ampacity, and rapid shutdown compliance under the Canadian Electrical Code. Both sets of drawings need a P.Eng stamp in most Canadian jurisdictions before a municipality will issue a permit, and provincial engineering regulators are strict about which revisions require a fresh stamp. This is the most technical piece of in-house solar engineering work, and the one most sensitive to code updates.
Permit Plan Sets for the AHJ
Every municipality reviews solar permits a little differently. Toronto’s process isn’t Calgary’s, and Calgary’s isn’t Vancouver’s. An in-house solar engineering team builds institutional knowledge of what each local building department wants to see, which cuts down on the back-and-forth that stalls a project for weeks. That local familiarity is one of the strongest arguments for keeping engineering close to the ground — but it only pays off if your projects are concentrated in a handful of jurisdictions.
Interconnection and Utility Coordination
Before a system can be turned on, the local distribution company needs to review the interconnection application, and for larger commercial systems, may require a distribution impact study. An in-house solar engineering team that’s already worked with Toronto Hydro, Hydro One, BC Hydro, or your regional utility knows their submission quirks. A generalist outsourced partner working across provinces may not have that same relationship history with every utility.
What Software and Tools Does an In-House Solar Engineering Team Need?
Payroll is only part of the bill. Running in-house solar engineering also means licensing the tools that make stamped drawings possible: a PV design platform such as Aurora Solar or Helioscope for shading and production modelling, CAD software for structural and site drawings, and often a separate structural analysis tool for racking attachment calculations under provincial wind and snow load requirements. Add plotter access or printing costs for physical plan sets some AHJs still require, plus ongoing code-update training as the Canadian Electrical Code and provincial building codes revise their solar-specific clauses. None of this is optional — a team without current software is a team producing drawings an AHJ will reject.
Most installers underestimate this line item when they first cost out an in-house solar engineering department, because software quotes are easy to defer until the team is already hired. Building the tool stack into your upfront budget, rather than discovering it project by project, is one of the more common mistakes installers make when moving to in-house solar engineering for the first time.
Signs You’ve Outgrown Your Outsourced Engineering Partner
Outsourcing isn’t a permanent state for every installer. A handful of signals tend to show up right before a company is ready to build in-house solar engineering capability, or at least renegotiate its outsourcing arrangement:
- You’re sending the same partner more than 30-40 plan sets a year and could staff a P.Eng at a lower per-project cost than you’re currently paying.
- Turnaround delays are costing you signed deals because your partner’s queue doesn’t match your sales pipeline’s pace.
- You need same-day revisions on change orders that an external firm’s standard SLA doesn’t support.
- Your project mix is concentrating in one or two provinces rather than spreading across many jurisdictions, which is exactly when in-house licensing coverage stops being a liability.
If none of those apply yet, the math almost always favours staying outsourced, even if in-house solar engineering feels like the more “grown-up” version of running a solar company. It isn’t — it’s simply a different cost structure that fits a different volume profile.
The Real Cost of Building an In-House Solar Engineering Team in Canada
This is where the decision usually gets made — not on paper, but on payroll. Solar PV design engineers in Canada currently earn somewhere around $75,000 to $100,000 a year on average, with senior, P.Eng-licensed engineers commanding more, especially in Alberta and Ontario where commercial construction demand is high. Add benefits, professional liability insurance for the stamping engineer, design software licences, and CAD tooling, and a single in-house engineer typically costs an installer well over $110,000 a year fully loaded.
That number only works if the engineer stays busy. A team that stamps forty commercial jobs a year justifies the overhead easily. A team that stamps twelve doesn’t — you’d have paid less per project sending the same twelve jobs to a specialized permit design firm.
When In-House Solar Engineering Makes Sense — and When It Doesn’t
In-house solar engineering earns its keep for installers with predictable, high-volume work concentrated in one or two provinces, especially commercial EPCs where in-house staff can also handle structural revisions, change orders, and RFIs without waiting on an outside firm’s queue. It also suits installers who’ve been burned by slow turnaround from a permitting partner during peak season and want direct control over the process.
It makes far less sense for residential installers running under twenty projects a month, companies expanding into new provinces where their current P.Eng isn’t licensed, or any business with seasonal volume swings. Those installers end up carrying a full-time salary through a slow winter for engineering capacity they only need in summer.
How to Transition to In-House Solar Engineering Without Disrupting Live Projects
Installers who decide to move to in-house solar engineering rarely do it in one step, and for good reason — a half-finished transition mid-project is how permits get delayed. A more workable sequence looks like this: hire the P.Eng and design staff first, but keep the outsourced partner running for two to three months while the new in-house solar engineering team ramps up on your project pipeline and your preferred AHJs. Route new projects to the in-house team once they’ve cleared a handful of permits successfully, and let the outsourced partner finish anything already in review rather than handing it off mid-permit.
Two mistakes show up repeatedly during this transition. The first is hiring a single engineer and treating them as the whole department — one person out sick or on leave stalls every project in the pipeline. The second is cutting the outsourced relationship immediately instead of overlapping it, which leaves no backup capacity if the new team’s estimated turnaround turns out to be optimistic. Installers who plan the overlap deliberately tend to avoid both.
The Middle Path: Engineering-as-a-Service for Solar Installers
Most growing installers land somewhere between “hire a full engineering department” and “cold-call a random stamping shop for every job.” Engineering-as-a-service — where a dedicated partner handles PE-stamped structural and electrical drawings, permit plan sets, and interconnection support on a per-project basis — gives installers predictable turnaround without the fixed payroll cost. One Place Solar works this way with installers and EPC contractors across Canada, the US, the UK, Australia, and New Zealand, producing permit-ready plan sets and PE-stamped drawings without the client carrying an in-house engineering headcount.
The advantage compounds when an installer is bidding work across multiple provinces. Instead of finding a separately licensed P.Eng for every jurisdiction, a specialized partner already has that coverage in place, so a company that just won its first contract in a new province isn’t stuck hiring or reciprocally licensing an engineer before it can even submit a permit application.
Picture a hypothetical mid-sized installer running residential and light-commercial work in Ontario: forty to fifty projects a year, growing but not yet at the volume that justifies a full-time P.Eng. That’s close to the profile where in-house solar engineering starts to make theoretical sense but the fixed cost still outweighs the benefit — exactly the gap engineering-as-a-service is built to fill, since the installer gets dedicated turnaround without carrying a salary through the slow months.
How to Choose Between In-House, Outsourced, or Hybrid
Run the numbers before you run the hiring process. Three questions settle most of the decision:
- How many permit-ready plan sets did you need last year, and how steady was that volume month to month? Under roughly 25-30 a year, outsourcing almost always wins on cost.
- How many provinces do you operate in? One or two favours in-house. Three or more favours a partner with existing multi-province licensing.
- What’s actually slowing your projects down right now? If it’s engineering turnaround, a better outsourced partner may fix that faster than an eighteen-month hiring process.
A hybrid model — a small in-house design coordinator who manages client relationships and QA, backed by an outsourced engineering partner for the PE stamp and heavy plan-set production — is increasingly common among mid-sized Canadian installers who’ve outgrown a single outsourced vendor but aren’t ready to carry a full engineering department.
The Bottom Line
In-house solar engineering isn’t inherently better or worse than outsourcing — it’s a cost structure that only makes sense above a certain, fairly specific volume threshold. Below roughly 25-30 permit-ready projects a year concentrated in one or two provinces, an outsourced or engineering-as-a-service partner will almost always beat the economics of a full-time payroll commitment. Above that threshold, and especially once you’re fielding same-day revisions and RFIs on a regular basis, in-house solar engineering starts paying for itself. Run your own numbers against last year’s project count before committing either way, and don’t be afraid to run a hybrid model while you figure out which side of that line your business actually sits on.https://oneplacesolar.com/contact-us/
Frequently Asked Questions
Do solar installers in Canada legally need a P.Eng-stamped drawing?
In most provinces, yes — commercial solar projects and many residential systems require structural and electrical drawings stamped by a licensed Professional Engineer before a municipal building department or the provincial electrical safety authority will approve the permit. Requirements vary by province, so confirm with your local AHJ.
Is it cheaper to build an in-house solar engineering team or outsource?
For most installers doing fewer than 25-30 permit-ready projects a year, outsourcing is cheaper. A fully loaded in-house P.Eng typically costs over $110,000 a year in Canada once salary, insurance, and software are included, which only pencils out against consistently high project volume.
Can one in-house engineer be licensed to stamp drawings in every Canadian province?
Not automatically. Professional engineering licensure in Canada is regulated provincially, so an engineer registered in Ontario isn’t automatically licensed to stamp drawings in British Columbia or Alberta. Installers expanding into new provinces often need reciprocal licensing or a locally licensed partner.
What’s included in a typical solar permit plan set?
A standard permit plan set includes site plans, structural drawings showing racking attachment and load calculations, an electrical one-line diagram, equipment specification sheets, and the PE stamp itself. Utility interconnection applications are usually a separate deliverable submitted alongside the permit package.
How long does in-house vs. outsourced engineering typically take?
In-house teams can turn around familiar jurisdictions quickly once they’ve built local relationships, but get bottlenecked during busy months since headcount is fixed. Outsourced partners with dedicated production teams often hold more consistent turnaround across seasonal demand swings, though this depends heavily on the specific partner’s capacity.
Does an outsourced engineering partner still take on liability for the design?
Yes. The stamping P.Eng, whether in-house or with an outsourced partner, carries professional liability for the design under provincial engineering regulations. Reputable engineering-as-a-service providers carry errors-and-omissions insurance specifically for this reason.