What are the most expensive costs in a home renovation?
- coraliefortin076
- Dec 1, 2025
- 8 min read
Renovating your house, cottage, or garage is both an exciting and demanding project. It's the perfect opportunity to transform a space to your liking, improve its functionality, or increase its market value. However, this type of project often raises many questions, especially regarding the budget. And the question that comes up most frequently among Plan Maison Québec clients is unequivocal: what costs the most in a renovation?
The answer is never as simple as a number or an average. In reality, every renovation project is unique, and costs vary considerably depending on the scope of the work, the materials chosen, the existing layout, and the desired level of finish. That's why at Plan Maison Québec, we believe that the key to a successful project lies in rigorous planning, based on a precise understanding of the most expensive elements of a residential renovation.
In this article, we unveil the budget items that weigh most heavily in a renovation, in order to help you anticipate your expenses, make strategic choices and invest wisely in the transformation of your property.
1 . The kitchen: one of the most expensive spaces to renovate
The kitchen is often considered the heart of the home—and rightly so. It's a central living space, both welcoming, functional, and aesthetically pleasing. But it's also, unsurprisingly, one of the most expensive rooms to renovate. The work involves several specialties: electrical work, plumbing, ventilation, carpentry, installation of complex surfaces, not to mention the high-end appliances that often complete the project.
Renovating a kitchen can easily cost between $30,000 and $50,000, depending on the complexity of the project, the size of the space, and the materials chosen. Custom cabinetry, natural stone countertops, multifunctional islands, and smart lighting systems are just some of the details that quickly inflate the bill.
1.1 Demolition and reorganization of the space
In many cases, clients want to open up the kitchen to the dining room or living room, creating an open-plan layout. This often requires demolishing walls, sometimes load-bearing ones, and therefore necessitates the involvement of engineers and the use of steel structures or support beams. This step alone can significantly increase costs, especially if it involves adjustments to the building's structure.
1.2 Upgrading the plumbing and electrical systems
Moving the sink, installing a dishwasher, or adding an island with a cooktop requires a complete redesign of the plumbing and electrical systems. This involves rewiring, adding compliant outlets, and integrating dedicated circuits for appliances. These tasks are often invisible but essential and require the expertise of qualified professionals.
1.4 Custom cabinet installation
One of the biggest expenses in a kitchen is often the cabinetry. Custom-made cabinets, designed to optimize every corner, offer a high-end look and uncompromising functionality, but they come at a significant cost. The choice of materials (solid wood, painted MDF, thermoplastic) directly impacts the budget. Adding features such as soft-close drawers, corner storage, or built-in modules also increases the price.
1.5 Surfaces and appliances
The choice of countertops—whether quartz, granite, or polished concrete—has a major impact on the budget. Similarly, handcrafted ceramic backsplashes, integrated range hoods, and high-end built-in appliances can double or even triple the cost of a renovation, depending on the desired standards.
At Plan Maison Québec, we encourage our clients to design a kitchen that is not only aesthetically pleasing but also perfectly suited to their lifestyle. Through custom design, we help you optimize every square inch, plan for efficient traffic flow, and prioritize the most cost-effective elements, both in terms of comfort and return on investment.
2 . The bathroom: small room, big budget
At first glance, a bathroom renovation might seem like a less daunting project. However, it's a highly technical space where every detail counts. Plumbing is ubiquitous, moisture control must be impeccable, and the finishing touches demand meticulous execution. All these elements combined explain why bathroom renovations are among the most expensive.
A complete renovation can cost between $15,000 and $30,000, especially if you add custom features like a bespoke ceramic shower, a freestanding bathtub, heated floors, or high-end faucets. The choice of materials—porcelain, quartz, treated wood—also significantly impacts the budget.
2.1 Reconfiguration of sanitary facilities
Moving a toilet, shower, or sink is never a simple matter. It often involves modifying the plumbing, which is frequently embedded in the floor or walls, potentially resulting in significant and costly work. Furthermore, if you're switching from a bathtub to a ceramic shower, you'll need to consider waterproofing, drainage, and the addition of built-in niches or benches.
2.2 High-end finish and water-resistant materials
Bathrooms are constantly exposed to humidity, which necessitates the use of durable materials: ceramic, porcelain, natural stone, mold-resistant paint, etc.
Installing ceramic wall tiles in the shower or on the floor requires extreme precision, specific materials such as waterproof membranes, and skilled labor.
2.3 Plumbing, ventilation and heating
Upgrading the plumbing in an older bathroom can reveal hidden problems, such as lead or oxidized copper pipes. Adding heated flooring, installing a powerful exhaust fan, or replacing a water heater are all factors that increase the cost, but are often essential for lasting comfort.
At Plan Maison Québec, we take all these specifics into account from the planning stage. Our rigorous approach allows us to design a bathroom that is both functional and elegant, minimizing costly surprises.
3 . The structure and the expansion: the heavyweight of the renovations
Altering a building's structure means working on its skeleton. Whether it's demolishing a load-bearing wall, reinforcing a foundation, adding a floor, or widening the space, costs can quickly escalate. These projects require specialized technical expertise, municipal permits, engineers, and sometimes even soil studies, in addition to a generally longer and more complex construction process.
Expansion projects often exceed $100,000, but they also offer the greatest potential to completely transform a home. An additional floor, a new wing, or a large open-concept living space can radically change your daily life.
The advantage of working with Plan Maison Québec is that you benefit from expansion plans that comply with building codes, the constraints of your property, and municipal requirements. We help you transform your ambitions into realistic and well-structured solutions, taking into account your budget and long-term goals.
4 . Electricity and plumbing: invisible but essential costs
They're often overlooked, but essential. Plumbing and electrical systems are the arteries and nerves of your home. During renovations, especially in older buildings, it's not uncommon to have to replace outdated or even non-compliant installations, which can represent a significant cost.
Moving appliances, replacing plumbing, or upgrading an electrical system to code can require extensive work, particularly if it involves multiple floors or if openings in walls are necessary. These projects can cost anywhere from $5,000 to $25,000, depending on the condition of the existing system and the scope of the changes.
4.1 Electrical panel upgrade and compliance
In many homes built before the 1980s, the electrical systems no longer meet current standards. Sometimes the entire electrical panel needs to be replaced, dedicated circuits added, or even the entire wiring rewired if aluminum wires or non-compliant installations are found. These repairs can cost between $5,000 and $15,000, depending on the area to be covered and the complexity of the system.
4.2 Addition of outlets and specialized lighting
Today's electrical needs are very different from those of 30 years ago. Adding USB ports, dimmers, recessed LED lighting, or home automation systems (smart lighting, connected thermostats, etc.) increases costs. These additions require careful planning and professional execution.
4.3 Security and certification
Finally, any major renovation often requires an electrical inspection or a certificate of compliance issued by a master electrician. This is an essential step to obtain your home insurance or sell your property later on. At Plan Maison Québec, we help you anticipate these requirements from the initial design phase of your project, to avoid cost overruns at the end of construction.
4.4 Finishing materials: where choices influence everything
While the structure is the foundation, the finishing materials are the showcase of your project. They're what you'll see and touch every day. But be careful: these choices, often aesthetic, have a direct and sometimes significant impact on the overall cost.
Hardwood flooring, solid wood interior doors, quartz or marble countertops, a handcrafted ceramic backsplash… all these elements can considerably increase the budget if the right choices aren't made. Some materials cost double—or even triple—the price of their standard equivalents, without necessarily offering better long-term performance.
At Plan Maison Québec, we help you make informed choices. Our expertise allows you to balance aesthetics, durability, and budget. You'll know exactly where to invest more and where to save without compromising the final result.
5 . Labor: a significant portion of the total budget
A renovation project involves a variety of professionals: general contractors, electricians, plumbers, carpenters, painters, architects, and sometimes even engineers. This diversity is essential, but it comes at a cost. On average, labor represents 35% to 50% of a renovation's total budget.
In a context where project timelines can be extended and the demand for qualified professionals is high, it is crucial to choose your partners carefully. Using experienced contractors guarantees not only a quality result but also better control over deadlines and costs.
Plan Maison Québec collaborates with a network of reliable and certified professionals. We help you compare quotes, understand estimates, and plan each phase of the project to maximize your return on investment.
6 . Unforeseen events: the often overlooked factor
Any experienced renovator will tell you: a project without unforeseen problems is extremely rare, especially in older homes. Costly surprises can lurk behind a wall or under a floor: non-compliant electrical wiring, rusty pipes, mold, cracks, outdated insulation, and so on.
These unexpected issues can represent up to 15% to 20% of the total budget, which is not insignificant. Ignoring this reality can jeopardize the continuation of the work or force you to make last-minute compromises.
6.1 Hidden problems in the walls or floors
Once the walls are opened, it's not uncommon to discover mold, vermin, outdated electrical wiring, or missing insulation. Repairing these issues, often urgent for health and safety, requires swift action, which increases the initial budget.
6.2 Delays related to materials or inspections
Another type of unforeseen event occurs when the chosen materials are out of stock, or when municipal inspections delay the work. These delays result in indirect costs: extended labor, prolonged rental of containers or temporary facilities.
6.3 Collateral damage or last-minute adjustments
Changing a single element mid-project can have a domino effect. For example, replacing a planned bathtub with a shower requires modifications to the plumbing, tiles, lighting… and sometimes even the room's dimensions. This kind of mid-project change of mind is a frequent source of budget overruns.
Through careful planning, rigorous preliminary inspections, and detailed technical plans, Plan Maison Québec helps you minimize the impact of these unforeseen events. We prepare you to face the unexpected calmly and efficiently, so your project can move forward without unnecessary stress.
7 . Custom design: a luxury that can pay off big
Hiring a designer to create a custom floor plan isn't a waste of money, but a strategic investment. Good design allows you to maximize every space, improve flow, reduce energy loss, and increase the overall value of your property.
At Plan Maison Québec, we create custom plans that respect your tastes, needs, technical constraints, and budget. The result is a harmonious, functional, and sustainable project—and above all, one without unpleasant surprises.
In summary: what actually costs the most in a renovation?
When analyzing the various expense categories in a renovation project, structural work and expansions clearly top the list of the most significant costs. These interventions require multidisciplinary expertise, official permits, and affect the very framework of the building, making them essential and often expensive.
Next come the kitchen and bathroom, two complex and technical rooms where the quality of materials and fixtures makes all the difference. Specialized labor and unforeseen circumstances can also increase the final bill. Working with Plan Maison Québec guarantees precise planning, a controlled budget, and a project that comes to fruition without any unpleasant surprises.
Conclusion : home renovation costs
Renovations represent a significant step in a homeowner's life. Whether it's modernizing an aging house, breathing new life into a cottage, or adapting a garage to new needs, every decision counts—and every dollar invested deserves careful consideration. So, you now know more about home renovation costs.
With Plan Maison Québec, you can be confident you'll get your project off to a great start. Thanks to our expertise in residential plan design, we help you anticipate costs, make the right choices, and avoid common pitfalls.
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