Heat Loss & Heat Gain Calculations in Aurora
CSA F280 heat loss and heat gain calculations for Aurora homes — room-by-room, stamped by a BCIN-registered designer, and formatted for your building permit.
If your permit application needs a heat loss calculation, or you’re building, renovating, or replacing a system and want it sized on real numbers, that’s what this service delivers. ON Point HVAC Design is based in Aurora and prepares load calculations for homeowners, builders and renovators across the town and York Region.
Did your Aurora permit application come back asking for a heat loss calculation?
This is the most common reason people land here, so let’s handle it first.
Under the Ontario Building Code, heating and cooling equipment for a new home or addition has to be sized from a calculated load — not square footage, not a rule of thumb. That calculation is done to CSA F280-12, and for most permit applications in Aurora the report has to be included in the package and stamped by a BCIN-registered designer. If yours came back marked incomplete or deficient for a missing load calculation, this is the document the examiner wants.
What you get from us:
- A room-by-room heat loss and heat gain report calculated to CSA F280-12
- Run at Aurora’s correct design temperature (see below — this is where generic reports go wrong)
- Documented assumptions — R-values, window specs, air tightness, design conditions — so the plans examiner can follow the math
- Recommended equipment capacity for heating and cooling
- BCIN stamp and Schedule 1 as required for submission
- Delivered as a permit-ready PDF in [X] business days
Since OBC 2024 came into force (January 1, 2025), new homes also require a Mechanical Ventilation Design Summary (MVDS) documenting the HRV/ERV system — an application without it is returned as incomplete even if the heat loss is perfect.
Why Aurora's design temperature matters
Every load calculation has to be run at the correct outdoor winter design temperature for the specific location — the January 2.5% value from the Ontario Building Code’s SB-1 standard.
Aurora’s design temperature is colder than Toronto’s −18°C. Aurora sits north of the city and at higher elevation, so a report run on Toronto’s number underestimates how much heat an Aurora home actually loses — producing an undersized recommendation and a report a careful reviewer can flag.
Running the calculation at Aurora’s actual design temperature is a small thing that a lot of generic, out-of-area reports get wrong. We run every Aurora calculation at the correct local value.
Who we work with in Aurora
Homeowners — usually because the Town asked for calculations, or because a past system never worked right and you want the next one sized properly.
Builders and general contractors — mechanical documentation for permit submission, on schedule, without chasing an installer for numbers.
Renovators — additions and renovations that change the load and need it recalculated.
HVAC contractors — subcontracted load calculations and duct design.
Frequently asked questions
Do I need a heat loss calculation for my Aurora building permit? For most new homes, additions and many renovations, yes. The Ontario Building Code requires equipment to be sized to a CSA F280 load calculation, and the report generally has to be stamped by a BCIN-registered designer and submitted with the permit package. New homes also now require a Mechanical Ventilation Design Summary under OBC 2024.
Are your reports accepted by the Town of Aurora? Our reports are prepared to CSA F280, stamped by a BCIN-registered designer, and formatted for submission across York Region including Aurora.
What do you need from me? Floor plans and elevations (PDF or DWG), your intended construction assemblies and insulation levels, window specs if selected, and the address. If you don’t have every detail, we’ll work with reasonable assumptions and document them clearly.
Do additions and renovations need a new calculation? Often yes — they change the load, sometimes enough that the existing equipment no longer suits the house. We calculate the revised whole-house load and tell you whether the current system can carry it.
What’s the difference between heat loss and heat gain? Heat loss is winter — how much heat the house loses on a cold day, sizing the heating. Heat gain is summer — how much it takes on, sizing the cooling. Both are needed to size a full system.