December 8, 2025
Technical Packages are now Available in the CMHC Design Catalogue
CHMC recently updated their Design Catalogue to include full technical packages that allow for a much more streamlined process when converting a traditional detached house to a multiplex. These are publicly available, open source plans that are code compliant and essentially ready to submit for permitting right out of the box.
Providing standardized plans removes one of the major barriers to entry that many investors face when planning a conversion. Many investors dread the expensive process of hiring an architectural firm to create these plans before submitting the plans for permit approval. This in turn will help add much needed housing supply to the missing-middle density housing crises.
What is the missing-middle housing crisis? The missing middle is everything in between highrise condos and single detached homes. This included laneway suites, garden suites, duplexes, triplexes, fourplexes, fiveplexes and so on. Multiplexes used to be very common in older cities but in the past few decades zoning rules have made low-rise neighbourhoods exclusive for single detached homes and multiplexes have become illegal. A staggering 70% of Toronto’s residential land is zoned for single detached homes. This has led to a severe shortage in housing supply and soaring prices in the past decade. As of 2023 major changes in zoning policies now allow for multiplexes, laneway and garden suites in most cities.
Providing free plans certainly won’t solve the housing crisis but free housing plans and policy change such as HST exemptions and lower development charges and faster approvals are definitely steps in the right direction. So what exactly do these free plans mean for you? Here are some benefits and drawbacks.
Benefits:
- These plans can potentially save a lot of time, money and headache through the permit approval process as they are code compliant once they have been adapted to your specific site.
- The technical packages include everything from technical drawings for structural, electrical, mechanical, plumbing and HVAC as well as a user guide explaining how to adjust these plans for your particular site.
- Building inspections will be much more streamlined in the construction process when using standardized plans.
Drawbacks:
- If you have a smaller lot, these plans may not fit. If you have a unique lot, you may still need to hire an architectural firm for a full custom design.
- Standardized plans may not be the most efficient use of space. This means less property value and rental income when compared to a custom design that is tailored to maximize space usage for the investor.
- Standardized designs also mean that you will be building the same thing as everyone else. Custom designs that are modern and sophisticated designs often lead to higher property values after the conversion.
It is also important to remember that using free standardized plans does not mean that you don’t have to hire architects and engineers. It’s still necessary to hire a firm to help you adapt these plans to your specific lot. However, this would save you money and time when compared to a full custom design from the ground up.
Currently the catalogue only has plans for accessory dwellings (like laneway and garden suites), fourplexes, rowhouses, townhomes and sixplexes but it does look like plans for duplexes and triplexes could be added in the future.

