A common misconception is that basements are not permitted in laneway suites, or that they are limited to unfinished space dedicated to storage or utilities.
Fact: a fully excavated basement level is fully permitted within the current as-of-right zoning by-laws and can be much more than just a place to put your hockey bags and golf clubs.
Basements are a great option on properties that offer limited depth for a reasonably sized above-grade unit and can provide the opportunity to move items like laundry, mechanical space and other infrastructural pieces below grade to alleviate valuable area in the floors above.
While building below grade can significantly increase the usable space in your suite, it does come at a substantial cost. That said, there is always a right time, place, and application for building downward.
Consider your use-case
In all cases, a laneway suite must contain a single occupancy, so a basement level is not permitted to house a separate rental unit from that above. However, a basement can be used by the main house tenant to provide additional storage or flexible space to offset the loss of a laneway garage.
It is also important to note that when introducing a basement to the plans, the ground floor typically can not accommodate a garage. Given the physical limitations of raising a ground floor to a level that can house a basement below, in most cases it is not possible to negotiate the change in grade from the laneway to an elevated garage slab within the tight confines of the laneway setback.
Our team has permitted many projects with basements thus far. The common thread amongst these builds is that the return on investment is not a primary driving factor. A lower level is commonly used to gain additional floor space where we are designing for an end-user or extended family – not necessarily a laneway tenant. Given the costs associated with the basement construction, it is often difficult to financially justify the benefits of an additional bedroom or recreation room when weighing the revenue gains against the associated costs.
Consider the costs
The premium to building a basement is not necessarily proportional to the area in which you excavate. A small basement can cost almost as much as a large one. The costs associated with shoring, excavation, and servicing remain relatively constant whether you build a 200 square foot basement or a 700 square foot basement.
To obtain a building permit for a laneway suite with a basement, you will likely require a set of shoring drawings and calculations demonstrating how adjacent structures will be supported during the excavation. These drawings and calculations must be prepared by a professional engineer and are coordinated with the architectural and structural designs. In most cases, you will also be required to provide a pre-construction vibration control study prepared by a third-party engineer. This report will outline the impact of the shoring installation on adjacent structures and can sometimes require inspections of your neighbouring buildings. These consultants contribute to additional soft costs that should be accounted for in your project budget.
Additional construction costs also typically include the shoring installation, excavation, disposal of material, concrete forming, waterproofing, foundation drainage, and finishing of the additional space. These items can increase the construction budget by up to 30%. The overall premium to the basement level depends on a variety of factors, considering access, adjacent buildings, soil conditions, protected trees, and existing utilities.
When contemplating your basement build, its critical to understand the site-specific characteristics that will impact its costing and overall viability with an experienced professional.
So, you have decided that a basement is worth the cost and adds intangible value to your investment. Here are a few questions to consider that will affect the final execution of your project:
What is my long-term use case: Do I need the additional space now, or will the basement be a provision for future need?
It is tough to introduce a basement after the fact. Consider how the build can be phased to align with your budget. To keep costs to a minimum, explore how the basement can be finished in future, and if so, prepare a plan that will locate future rough-ins to make for an easy fit-out.
Are there any circumstantial obstacles to building a basement on your lot?
Work with a design professional to determine if there are any trees in the vicinity that are protected by the city’s private tree by-law and determine the likelihood of excavating into protection zones if they exist. Be conscious of overhead wires, poles, light stands or other obstacles that may impact access of machinery or disposal of soil. Also assess any adjacent structures and how their condition or location may impact access to the property, or how the excavation could affect their structure.
How will the basement be used? What is the value add for the short and long term?
Consider how the basement will be occupied and what size of space you can realistically achieve below grade. Ask yourself what the value of that space will be in the short and long term. Is it an additional bedroom, storage space, or utility area? Ensure to factor in access, fire separations, window wells and other functional requirements in the purview of zoning by-laws or building codes. Plan the project wholistically, developing plans how the basement will impact spaces both above and below grade.
Are there other means of achieving the area I need?
No two lots, programs, or suites are alike. Assess the principles behind your priorities and consider alternative options that satisfy your criteria. Efficient planning of above-grade levels can often uncover additional usable space. If it is storage space you seek, perhaps this can be attained with a shed, storage structure in the yard, or by reallocating some space in the existing house. It may also be worthwhile to consider seeking a minor variance at the Committee of Adjustment if your lot is in a unique condition that merits a larger building footprint, or reduced setbacks and separations.
Like any major project, the process should begin with assessing the key priorities against your budget, circumstances, and goals. Ensure you are considering the costs and rewards of several scenarios for a laneway suite on your lot. There are many capable and experienced providers in the city that offer free estimates, site assessments, and detailed information available online. We highly recommend collecting as much information as possible and, if necessary, making a small investment in developing preliminary plans and budgets tailored to your property with a qualified designer. Lanescape offers preliminary design packages that include multiple plan options tailored to your scenario, alongside a financial schematic to inform you on how best to exceed your goals.
As always, assemble a dream team that fosters communication, explores various scenarios, and thinks outside the box. We look forward to seeing you in a laneway soon!