HVAC design for a Campbellford building permit

Campbellford publishes no mechanical checklist, which means the requirement usually arrives after you have applied. Here is what they will want, and the design temperature your calculation has to use.

The design temperature

Every number in a heat loss calculation depends on the outdoor temperature the house is designed for, and the province sets it — not the designer.

Campbellford: -23 °C (-9 °F) — January 2.5% design temperature January 1%: -26 °C · Degree-days below 18 °C: 4,280

Source: Ontario Building Code SB-1 (2024), Table 2 — Climatic Design Data. Basis: listed in SB-1.

A calculation run at the wrong design temperature is wrong by roughly the amount the temperature is wrong by, and it is one of the commonest reasons a reviewer sends a package back. If you are comparing quotes, ask which design temperature the designer is using before you compare anything else.

What each document actually is

Document	What it is
Heat loss and heat gain calculations	The room-by-room load. Everything else is sized off this.
Formula sheet	The working behind the numbers, so a reviewer can follow them.
Thermal load calculator	The envelope assemblies and areas the loads were built from.
Air leakage calculator	The infiltration assumption, stated rather than buried.
Residential ventilation summary	The OBC 9.32 ventilation design, on the HRAI summary form.
Duct design and layout	Supply and return sizing, register locations, cfm per room.
Energy Efficiency Design Summary	How the house meets SB-12, prescriptive or performance.
Radiant in-floor design	Loop layout, spacing, manifolds and lengths.
Hydraulic load calculations	Flow and head for a hydronic system.

Who is allowed to sign it

You hire a qualified designer. They complete the Schedule 1 Designer Information Form with their BCIN and take responsibility for the design.

You are the owner, building on your own lot. Ontario Building Code Division C, Article 3.2.5.1.(3)(b)(i) exempts an owner who designs a house they own from the designer qualification requirements. You can file the documents yourself. The calculations still have to be correct — the exemption is about who may design, not about the standard the work has to meet.

Tell us which applies and we will tell you what you need before you pay.

What it costs

	Includes	Price	Turnaround
Heat loss and heat gain	Room-by-room loads, worksheet, design conditions, equipment sizing basis, assumptions, seal page	$395	48 hours
Full mechanical package	The above plus ventilation design, duct design and layout, EEDS, and radiant layout where applicable	$695	48 hours

Forty-eight hours from complete plans and payment. If the building department asks for a correction to something we got wrong, we fix it and reissue at no charge while your application is open.

See a complete sample package →

Common questions

Do I need all of these documents? Not always. A heat loss calculation alone satisfies some permits; a new dwelling with a hydronic system needs close to the full list. Send the plans and we will tell you which.

The department has already asked and my build is held up. That is the most common reason people call. The 48-hour turnaround exists for exactly that.

My HVAC contractor says he will size it. He may be right about the equipment. The building department still needs the documents, and the Code requires equipment capacity to be based on the calculated design heat loss.

I’m adding a basement apartment, not building a house. Different job: no drawings, an existing furnace, and a check that it can carry both units. Here is how that works → The design temperature and the checklist above apply to it just the same.

Does an ICF or high-performance house change the answer? Same procedure, different inputs. The result usually comes out substantially lower, and more of the difference comes from air sealing than from the wall’s R-value. We run that comparison on every job.

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Send your plans — we’ll tell you what you need before you pay →