The Difference Between Permit Drawings and Construction Drawings

I bet you didn't even know there was a difference?

Building Code Requirements

Permit drawings contain information that the building inspector at your municipality wants to see, to prove the building conforms to the Ontario Building Code. Things the building department cares about are washroom sizes (ensuring they are barrier-free), fire safety, plumbing design, and basic structural if required.

If, as architects, we gave the building department a basic permit set, with the minimum information, your contractor would not be happy with that set and would be calling me all day for dimensions and details. That's because the building department doesn't care about room sizes generally, doesn't care about non-loadbearing wall construction, nor about finishes.

Construction Details

A basic permit set of drawings doesn't look at all the facets of the building in detail. It is an overall picture of how the building is to be built. A Construction set looks at many areas and detail of the building a works through how to construct every detail ahead of time to avoid surprises, and unsightly mistakes! For example a construction set of drawings will detail a connection between an intersecting roof and wall to make sure that there is sufficient insulation and no air leaks to enhance building energy performance, and still look good.

A construction drawing set looks at some of the key intersections in the project and works through how they should be constructed. Whether its the continuity of the insulation and air barrier in your exterior walls to ensure good energy performance, or a special bulkhead construction detail, a construction set thinks about these details and resolves them before constriction starts to ensure a neat, tidy, and no surprises (often in extra costs) finished product.

Cost Control

A good set of construction drawings protects you from unforseen extra costs. All the many decisions you make along the process of design is recorded and and transferred to the contractors via the drawing set. Decisions like USB outlets, special light fixture switches, data connections, special interior finishes, or unconventional decisions. Remembering your normal is my normal, or your contractors. We all have different standards and normals and without information the contractor will price 'his normal' high or low of what you actually want. Where a special request that isn't 'normal' is documented in the drawings, the contractor is required to price it in his quote up front and can't come back later and tell you that is not 'normal' and will cost you extra.

The other major difference between permit drawings and construction drawings are the details.Of course the Construction drawing set cost more up front, but decisions and changes are cheap on paper, and could save you thousands in extras later!

Contents

A permit set of drawings may contain around 10-14 drawings, where a construction set could be up to 30 drawings, notes, schedules, and details.

This is a comparison chart that gives you an idea of the content difference between the two types of drawing sets.

So when you talk with an architect, contractor, or BCIN designer, make sure you know which you need and want for your project!