What to Expect When Building an In-Law Suite?

Want to build a cozy suite that compliments your main family home? You’re at the right spot. An in-law suite is a great way to have your family close to you while adding extra value to your property. We’ve compiled a detailed estimate cost breakdown to make your dream suite a reality.

How To Plan Your In-Law Suite?

Before you start, consider how the in-law suite will be used. Will it be a full-time residence for a parent or in-law, or more of a guest space? Plan out the number of rooms, amenities, and overall layout based on your answer.

For comfortable living, the suite should include: a bedroom, bathroom, kitchen, living area and laundry. Depending on your lot size, you can choose between a basement unit or backyard unit and a private entrance or even a separate outdoor space for added privacy.

Cost Breakdown

The average cost to build an ADU (Additional Dwelling Unit) ranges from $40,000 to $125,000 or more depending on your design preferences and needs. You can expect to spend about $100 to $200 per square foot, including materials and labor.

In-Law Suite Costs for Labour

Architect: Local architectural services in Kingston will cost about 10% to 20% of the project’s total cost. For example, for a $100,000 in-law suite, you’d spend an additional $10,000 to $20,000 for an architect.
Electrician: A new in-law suite will need electrical work, which costs an average of $50 to $100 an hour. Work also includes essential changes to your home’s current electrical system. For safety, the unit needs lighting leading to an outdoor exit, as well as smoke alarms and carbon monoxide detectors connected to the main home.
Plumber: Both the bathroom and kitchen of the suite will require new plumbing, and the bathroom must be connected to the sewage system. Plumbers charge about $200 an hour for these intensive jobs. You can expect to spend:

Water main installation: $600–$2,500

Plumbing pipes: $300–$2,000

Sewer installation: $1,500–$5,000

HVAC: Depending on the size of the space, HVAC (heating, ventilation, and air conditioning) can be a relatively inexpensive extension of your existing systems, or require the installation of a new system. A new HVAC system costs around $7,500 on average.
General Contractors: You can hire local addition and remodeling contractors in Kingston for many parts of the process, such as building the structure, painting the interior and exterior, laying floors, and installing windows. They’ll typically cost you 10 – 20% to oversee the entire project. Additional workers who build, install, and paint cost about $100 to $300 per laborer, per day.

In-Law Suite Material Prices

Support beams and roof trusses	$15 to $30 per square foot.
Drywall and insulation	Drywall will cost $400–$600 for every 100 square feet, and insulation will cost $0.30–$1 per square foot
Foundation materials	$400–$700 for 100 square feet
Bathroom plumbing	$1,500–$4,000 for 100 square feet.
Plumbing fixtures	$400 to $2,000 for each plumbing fixture.
Electric meter	$2,000–$5,000.
Water heater	$600–$3,000.
Paint	$5,000 for interior, $8,000 for exterior.
Siding	Around $12 per sq. ft.
Windows	$100 to $1,500 per window.
Doors	$500 to $5,000 each.
Floors	$5 to $20 per square foot, with options like hardwood or marble costing more, while laminate or vinyl will be less expensive.