best value to add new space

Question Icon
Posted by: from Toronto
1/24/2015 at 9:30:21 AM


I live on a narrow 20' x 130' lot in the west end of Toronto near Bloor. I have a detached house with approximately 1000 square feet of living space and a small finished basement with another 400 square feet. I would like to add space to my home in the most cost effective way possible and I am considering 2 options.

Option #1 going into the attic/ adding a third floor.

I have a hipped roof with a ridge that runs most of the length of the house and is about 7 feet high. It is a rafter roof system. I know this is not high enough and that we would need to gain floor space with extra height. Im not sure if this could be done with dormers/ skylights or if would need to raise the roof or remove it and add a 3rd floor. I would access the attic through stairs running directly above the current stairs and taking floor space from a large closet for the landing. My initial thought is to build a master bedroom with an ensuite on the third floor but I've also considered a open guest room/ playroom/ office.

Option # 2 is a 2 story rear addition with a full basement. I would connect the basement to the existing basement. On the main floor I would make the kitchen currently at the back of the house larger and add a family room with sliding doors leading to a deck behind it. Upstairs I would enlarge a Bedroom. The house currently sits about 1.5' from the property line on either side. In the back on 1 side there is a 3' x 10' section beside the kitchen 'missing' from the house (there's a door leading to a small side deck that leads to the back). The additon would ideally be the full width of the house and would include extending the narrower part at the back of the house to the same width as the rest of the house. I'm not sure this is allowed/ possible. There is not a lot of room between houses to access the backyard for construction equipment but I do have a laneway and garage at the back to gain access.

Let me know if any more information is useful. I'm only looking for advice and costs at this time.



User Icon
Suzanne from Built By Pros Inc. in Toronto
Date/Time1/24/2015 at 10:47:57 AM


Good questions and thank you for the details.

The first thing you will need to find out is what you are able to do within the city zoning policies. The third floor option could be restricted by the Maximum allowable height of homes in your area. The addition option could be restricted by either the max allowable ft2 for your home or by the back yard set back ( mandated back yard size). Every house in Toronto is bound by these zoning policies and since both of your options will require a building permit, you will need to first obtain a letter of approval from the zoning department. Your contractor or any architect can find this out for you once they have your property survey or site plan. You can also go to city hall with your survey or site plan and ask for a consultation with the zoning department. (be prepared for a very long wait as it is first come first serve).

If the zoning bylaws do not allow the changes you are looking for you can appeal using the Committee of Adjustment" process which involves presenting your case to the board for permission to get a "variance". You should use an experienced contractor or architect to prepare and present the proposal on your behalf as it will strongly increase your changes of success. The process will cost a $1500 fee, plus the cost of preparing the drawings and application (+/-3000$).

As for the feasibility of each option; adding space in a 7' high attic is not recommended because of the space required to adequately support and insulate the roof will make the new ceiling less then 6'7" which is the min ceiling height for usable space (building code). The roof will need to be removed and replaced with either a new hip/gable roof or flat roof. The cost of doing so is very similar to the cost of the new 1 storey addition with unfinished basement or crawl space. Adding a 2nd floor to the addition will make it more expensive.

As for cost: You can budget $20-$25,000 for demo and disposal of existing, $10,000 for all drawings, design, permits, $150/ft2 for construction, plus extra for any features, like bathroom, kitchen, fireplace, built ins, upgraded exterior (eg. brick vs stucco).

User Icon
Date/Time1/24/2015 at 11:41:18 AM

Just to add, if you are looking for the best Value for resale then you should find an experienced local realtor and find out which option would increase your resale the most, based on the cost to do the renovation. The third floor obviously being the cheaper of the two. However I always tell people if your planning on staying in the house for a number of years, do the work that would benefit you and your family the most. You have to consider the years of use and enjoyment you will get from the renovation.

User Icon
Handyman Search in St. John's
Date/Time1/24/2015 at 12:33:02 PM

Hi David, your best bet is to speak to a couple of Contractors to get the information you need. You should have them visit your property so they can give a recommendation and quote.

User Icon
Date/Time1/24/2015 at 6:16:46 PM

Hi David,

Susan's reply was very good. Cost can vary from that depending on a number of variables though.

Another reply made a very good point.....check with experienced realtors in your area and get an opinion of what will work for resale as well.

Prior to my moving to the Niagara region three years ago my company renovated multiple homes in the downtown Toronto area, as well as a number of additions.

Most of the additions were additional floors. But do check out the height restrictions with the zoning and building department.

James Fram

Search the TrustedPros directory and discover the best contractors in your area.

Find your home service pro
Great renovations start with a great contractor.

Since 2004, TrustedPros has been helping homeowners find the right contractor for their home improvements and repairs.

Post Your Project

Within hours you'll be comparing offers from top-rated professionals. It's free to post and you're under no obligation to hire.

Trustedpros Inc. does not warrant the accuracy, completeness, safety, legality or usefulness of any Content, or Whether Content is Current and up-to-date, and TrustedPros Inc. Shall have no liability whatsoever with respect to your use or reliance upon any content or for content being removed or otherwise ceasing to be available. Please refer to the terms and conditions of use of this websites for more details.

Get Free Estimates

Post your project and compare offers from top-rated pros.