Add a Unit to the Top

The rear addition case study involves adding a distinct living unit by building a new structure connected to the rear of the existing structure of the house. The only changes made to the existing building are to the rear wall which now acts as the fire separation and unit demising wall. Unit access to the rear addition exists off the side yard of the site. Major considerations include allowable building area, construction implications, and plumbing.

Design Specifications

# of Units: 1

Existing House
4 Bed / 2 Bath
107.3 sqm (+107.3 sqm basement and garage)

# of Units: 2

Unit 1 – Existing House
4 Bed / 2 Bath
101 sqm (+107.3 sqm basement and garage)

Unit 2 – Top Addition
2 Bed / 1 Bath
60.5 sqm

Shared Space
Laundry
Storage Rooms

Cost Considerations

*This sample design might cost somewhere in the range of $680,000 - $1,203,000

Whenever you are deciding what type of unit to add, it is important to understand what the major cost considerations are. For a top addition, these are:

Unit Access
Unit Egress
Fire and Sound Separation
New Bathroom(s)
New Kitchen(s)