The construction mortgage demystified (part 2 of 2)

How it all works

A construction mortgage differs from your traditional mortgage in that nothing exists yet. Most traditional mortgages involve a down payment. So, for ease of calculation, let’s say you have a 500,000 mortgage that requires 10% down, that means you have to front $50,000 and the remainder is what the bank actually issues as your mortgage — $450,000. 

With our construction mortgage, the bank financed 100% of the land cost, which meant that at the time of purchase, we did not have to pay anything on the land.* We have only to pay the interest on the land until we start the build. As far as down payments go, at this pre-build stage, it has no one to go to, which is why they financed 100% for us. The bank assumes that we will pay the 10% (downpayment, if you will) towards the construction portion of the mortgage ourselves. So the actual mortgage amount granted has this amount subtracted from it already. 

Let’s say the land cost was $200,000 (A) and the build cost was $400,000 (B), for a project total of $600,000 (C) (these numbers are for illustration purposes only). The actual mortgage would then be for $540,000 (C minus 10%). Meaning you think it’s going to cost $400,000 to build, but are hoping to build it for less :p Capeesh? It took me a while to wrap my head around.

Construction mortgage breakdown (example)
Land cost (A) 200,000
Build cost (B) 400,000
Project cost (C) 600,000
Mortgage (C – 10%) 540,000
Effective build cost 340,000

When the build begins

As mentioned, until we start the build, we only pay interest on the land portion of the mortgage (like a line of credit, where you only pay the interest on the portion used). When we’re ready to start the build, we will be allocated a series of disbursements based on percentage of construction completed. CMHC decides what these breakdowns should be, and the bank issues the funds once someone has been out to site to confirm that the work has indeed been done. This means that money will be tight up until our first disbursement is issued (because we’ll have to front the money ourselves, and/or have to negotiate with our subcontractors for flexible payment terms). 

The disbursements used by CMHC %
Excavation, foundation 9
Damp proofing, drain, back fill 2
Frame, sheathing, roof 20
Doors, windows 6
Rough electrical 4
Rough plumbing 3
Insulation, air vapour barrier 5
Basement slab 2
Exterior finish 12
Drywall 9
Complete electrical 1
Complete plumbing 4
Kitchen cabinets & bathroom vanities 6
Finish carpentry 5
Interior painting 2
Flooring 4
Site work 3

We are hoping that the above is just a guide and there’s some leniency. Because we’re building a Passive House, we’ll be investing a lot more on the envelope than a traditional build. So our numbers will be skewed towards insulation and windows and less towards HVAC and finishes. We shall see.

We can ask that the bank gives us as many disbursements as we want, but CMHC’s fees have allowed for four. Should we choose to ask for more, there are additional fees — not only from CMHC but also for lawyers and appraisers too. When we are ready, we let them know and they send someone out to confirm that the work we said was done was, in fact, done. We will likely ask for our first disbursement once the excavation is complete and our foundation is poured.

As the disbursements are issued, our interest payments will rise as our mortgage advances. For example, after the foundation is poured, CMHC may deem the construction 15% complete, at which stage we ask for our first disbursement. Using the numbers from earlier, we have $340,000 left from which to build our house. So our first disbursement will be 15% of $340,000, or $51,000. And we’re now paying interest on $251,000 up until our next disbursement/withdraw. See table below for the full story.

At the end of the process, when work is certified 100% complete, we will switch our mortgage over to a traditional mortgage. At which stage we will likely have some options. Do we want to take out a home equity line of credit because our completed house will be appraised at a higher value? Thoughts for later on…

Phew! I did it. And you made it to the end. Hope this helps other curious minds. Many people I've met have expressed interest in building, but aren't really sure how. Understanding the construction mortgage, and the fact that we actually might be able to get one with zero money down (for the land), was what set our wheels in motion. I still scratch my head over the fact that they were willing to give us so much money. But the bank's not stupid. They'll make their money.

Mortgage disbursement calculations (example)
% Complete x Build cost
(B = $340,000)
Cumulative withdraws
on mortgage
15 51,000 51,000 251,000
50 170,000 119,000 370000
75 255000 85000 455000
100 340000 85000 540000

  • Earlier I stated that we did not have to pay anything on the land when we bought it because it was 100% financed. What the mortgage calculations do not take in to account are the soft costs. I wrote a post earlier about those effing soft costs. When we purchased the land, we had to pay the GST on the purchase, immediately, in cash (bank draft). We used equity from the sale of our house towards this. We also had to pay the city permit application and will soon be paying development fees (upwards of $21,000 or so) once the permit is actually issued. Yep, those soft costs hit hard. Ouch.

  • An uninsured construction mortgage will typically require 20% downpayment on the project, and be subject to a holdback of 10% on each disbursement. Something to bear in mind if this is the route you go.