Land and Building Costs over duration of a project

Hi all – I’ve been reading through some of these development threads and they are very interesting.
I am currently a property investor and own 4 properties but have recently started reading up on small developments which I am looking to start in maybe a year or two when I feel like I’ve learned more about it.

I did have one query which I’ve summarised below – obviously when doing a new development there are two main costs – costs to purchase the land, and cost for construction.

As an example, lets assume that it will take 6 months to complete building 7 units on newly purchased land from start to finish, plus another 3 months to sign up tenants to occupy all of the units that have been built.
Regarding cost for purchasing the land, lets say you borrow $200k from the bank. This is roughly $10k in interest payments annually.
Regarding cost for construction, lets say you borrow $1 million from the bank. This is roughly $50k in interest payments annually.

Based on the bank interest payments above, over a period of 9 months, this equates to around $45k, or $5k per month payable in interest for the 9 months. This means you will only start offsetting interest payments with the rental income from the 10th month, so you will be out of pocket $45k in interest payments from the time you purchase the land to the time you get full occupancy in each of the completed units – do most development generally work this way? Just wanted to ensure I understood the big picture here and to plan forward that developers will be out of pocket for the duration of the building process and till units have been occupied.

Thanks,
Ajay