Your Building Permit Package Is Not Enough: The Case for Full Construction Drawings

Building a custom home in Ontario is likely the largest financial investment you will ever make. Yet a surprising number of homeowners hand their contractor a building permit package — and nothing more — and expect the result to reflect their vision. It almost never does.

The building permit package gets your project approved by the municipality. It satisfies the Ontario Building Code. It tells the inspector what they need to know. What it does not do is tell your contractor what tile to install in the master bath, what brand of hardware goes on the kitchen cabinetry, what the ceiling height is in the basement rec room, or what gauge of wire should be run to the home theatre. That gap — between what the permit requires and what you actually want — is where custom home projects quietly go off the rails.

The solution is straightforward, though it requires an investment of time and money upfront: a full set of construction drawings and a complete specification package, prepared by your architect before a single shovel goes in the ground.

The Lump Sum Contract Problem

Most Ontario homeowners hiring a general contractor for a custom build will negotiate a lump sum contract — a single fixed price for the entire project. On the surface, this feels safe. You know your number. You can budget around it.

But a lump sum contract is only as good as the documents it is based on. When a contractor prices a lump sum against a thin permit package with minimal specification, they are not pricing your dream home — they are pricing the cheapest compliant version of it. Every unspecified item is a blank that gets filled in with whatever is most economical. And that is not the contractor’s fault. That is exactly what the contract structure incentivizes them to do.

An unspecified item is not a blank waiting for your input — it is a decision the contractor has already made for you, and it will always be the least expensive option available.

Without drawings that specify the brand of sump pump, the contractor installs whatever they have in their truck. Without a door schedule that lists the manufacturer, model, and hardware set for every opening, the contractor buys whatever is in stock at the building supply that week. Without a finish schedule that specifies the exact flooring product down to the SKU, the contractor substitutes the closest thing at their preferred price point. Multiply that across hundreds of decisions in a custom home, and the gap between what you expected and what you received can be enormous — and enormously expensive to fix after the fact.

Permit Package vs. Full Construction Drawings

What does a building permit package actually include, compared to a full set of construction documents? The difference is significant:

The Specification: Where Every Decision Lives

Experienced architects know that the drawings tell the contractor where things go. The specification tells them exactly what those things are. The two documents are inseparable on a well-run project, and the specification is where the real detail lives.

A thorough specification package — structured across the construction divisions — covers every material, product, and system in the building. Not in vague terms, but specifically: manufacturer, product line, model number, finish, grade, and installation standard. This is not bureaucratic over-engineering. It is the only reliable way to ensure that what gets built reflects what was designed and what the client paid for.

Consider the range of decisions that a proper specification resolves before construction begins:

The Project Management Route Has the Same Problem

Some homeowners who recognize the risks of a lump sum contract opt instead for a construction management or owner-managed approach — hiring trades directly and overseeing the process themselves or through a project manager. This model can work well, but it does not escape the specification problem. It actually amplifies it.

Without a full specification, an owner or project manager must make hundreds of product selections in real time — under deadline pressure, with trades waiting for answers, while simultaneously managing budget, schedule, and site logistics. Every unspecified item becomes a research project. Every decision point becomes a potential delay. The time cost alone can be staggering, and decisions made under pressure rarely reflect the careful consideration that should go into a home that will be lived in for decades.

The time you spend specifying everything before construction begins is paid back tenfold in decisions you never have to make under pressure on-site.

A complete specification package, prepared during the design phase when there is no urgency and no contractor waiting, eliminates this entirely. Every product decision has been made, documented, and approved. When the tile contractor asks what grout colour goes in the mudroom, the answer is already in the specification. When the electrician needs to know the model number of the under-cabinet lighting, it is in the specification. When the HVAC contractor asks about the thermostat brand, it is in the specification.

What Full Drawings Actually Cost — and What They Save

The honest conversation about full construction drawings comes down to fees. A complete set of construction documents and a full specification package costs more than a permit package. The difference, depending on project scope, might range from a few thousand dollars to a meaningful percentage of the design fee. For a $1.5M to $2.5M custom home — which is a realistic range for quality custom construction in Southern Ontario today — that additional investment is proportionally small.

What it buys is control. Control over what gets built. Control over the quality of every material and system in the home. Control over the contractor’s substitution choices. Control over your budget, because a detailed specification eliminates the ambiguity that contractors exploit — sometimes unconsciously — when pricing and executing work. And control over your peace of mind during what is inevitably a stressful process.

• Fewer change orders: Unspecified items are the primary driver of change orders during construction. A complete specification dramatically reduces the frequency and cost of mid-construction changes.
• Better contractor pricing: Contractors price with more precision — and more competitively — when the scope is fully defined. Ambiguity in tender documents gets priced conservatively, which means you pay more for less certainty.
• Faster decision-making on site: With specifications in hand, the contractor and their trades can proceed without waiting for owner input on routine product questions. The project moves faster.
• Accountability and recourse: If the installed product does not match the specification, you have a documented basis for requiring a remedy. Without specifications, you have no such recourse.
• Peace of mind: This is underrated but real. Knowing that every decision has been made, documented, and is being executed to a standard removes an enormous amount of anxiety from the construction process.

The Bottom Line

The money you invest in complete drawings and specifications is not an additional cost — it is a transfer of risk. You are paying to move the risk of poor product selection, costly substitutions, and mid-construction decision fatigue out of your project entirely. That is money very well spent.

What to Ask Your Architect

If you are building a custom home in Ontario, the most important conversation to have with your architect early in the process is about the depth of construction documents they intend to produce. Ask directly: will this include a full specification, or only permit drawings? Will every product be specified by manufacturer and model? Will there be a complete finish schedule, door schedule, hardware schedule, and plumbing fixture schedule?

If the answer is anything less than a full package, ask what it would take to get there. In most cases, the additional investment is modest relative to the total project cost — and the protection it affords is substantial.

At Lima Architects Inc., full construction drawings and complete specifications are standard on every custom residential project. We specify everything — from the structural system to the sump pump brand to the finish on the door lever. Not because it is required, but because it is the only way to ensure that what our clients imagine is what actually gets built.

A custom home built to a complete specification is not just better quality — it is a fundamentally different experience for the client, from the first day of construction to the day they move in.

Building a home is a once-in-a-generation decision for most families. It deserves the full attention of the design process — not just enough documentation to satisfy the building department. Invest in the drawings. Specify everything. Protect your project.