Thanks, I did and do plan on giving the town a call. I just figured posting to this community forum would provide some experience from others who have done similar.
Apparently I was wrong and posting here only gets me responses from unhelpful and unfriendly vampires.

Let's see how many more people can tell me too call the town. It's not like I was going to go pick up a permit from the local home depot.

If we can't ask these sorts of questions here I am uncertain what this forum is for besides everyone having a bitch session over planned road closures and traffic light installations that they have minimal control over.

Thanks.

J&L, looks like the answer is yes... I was just on the site last night looking at something else:

https://www.milton.ca/en/build/buildingpermitfaq.asp
Expand the section that lists examples of projects requiring a permit, and pergolas are there.

When is a building permit required? (Types of projects)

Under the Ontario Building Code Act, a building permit is required for the construction of any structure exceeding an area of 10 m2. (~108 ft2.).

A building permit is required for new construction, additions, alterations, renovations, relocations, demolitions, and repairs or rehabilitation of a building or structure. Some minor repairs do not require a permit. Listed below are some typical projects and whether or not they require a permit. Heating Ventilating and Air Conditioning permits (HVAC), and/or plumbing permits may also be required as a separate permit but are usually reviewed as part of the overall building permit. It is the responsibility of the owner to obtain a building permit. The approved drawings should be kept on the building site and be readily accessible at all times.


Examples of projects that require a building permit:
Finished Basements
Accessory Apartments
Decks (regardless of size if attached to house)
Accessory Building (shed, gazebo, cabana, carport, garage, farm building, poly hoop, etc...)
Additions (regardless of size)
Construction of attached and detached garages
Enlarging an exterior opening and any new interior opening in loadbearing wall
Finishing previously unfinished spaces such as rec. rooms, family rooms, attics, etc.
Converting any space/room into a bedroom,
Repair and underpinning of foundations
Construction of tent or group of tents greater than 60m2
Installation of pool enclosures
Repair or Replacement of the drainage/weeping tiles around the foundations
Any alternation or extension to plumbing system and heat/ventilation duct system
Replacement of the existing siding with brick/stone veneer or stucco
New or replacement of a Wood fire place
New or replacement of Masonry and Concrete Chimneys and Flues
Repair/Alterations to a Septic System
New septic tank
Building a retaining wall that exceeds 1.0m in height
Demolitions

You should also check to see if the Pergola attached to the house will affect your property taxes. I know that in Toronto and Mississauga if you build anything attached to the house, such as pergolas, a garage, or even a deck, would automatically trigger an increase to your property taxes.