I have the following problem to solve.
I have a total area of At (Area Total). Example 1000m2
Within that area I want to find out how many 1 bedroom, 2bedroom, and 3bedroom units I can fit. The areas for each unit are A1, A2, A3 respectively. Example 55m2, 80m2, 95m2.
I want the number of units to be calculated using a percentage. P1, P2, P3. respectively. Example 20%, 70%, 10%.
What is the formula for 1bedroom, 2bedroom and 3bedrooms to fit in a total area by certain percentages?
I started out calculating the percentage of the total area. I.e. 20% of 1000m2 and then divide by 55m2 for 1bedrooms. But the percentage is then calculating based on area rather than quantity.
I then started to go down the path of dividing the total area by one of the bedrooms to get a quantity and then working out a percentage of the one bedroom compared to the others but got a bit lost.
This is a formula I want to calculate to work out residential unit potential for a development site.
First work out:
V = (P1/100) * A1 + (P2/100) * A2 + (P3/100) * A3.
That's the average area of an apartment. In your example V=76.5. Then work out:
T = At / V
That's the approximate total number of apartments. In your example T~=13 Next, work out:
U1 = T * (P1/100),
U2 = T * (P2/100), and
U3 = T * (P3/100)
Those are the approximate numbers of apartments. In your example that's ~2.6, ~9.2 and ~1.3. Next, round these numbers down to make sure it all fits, giving 2, 9 and 1. Finally, work out the area this gives and see if you can fit another one in. In your case you get 925 and so can fit another 55 in. The last part is manual because there's no simple way to get whole numbers to fit together.
None of this accounts for corridor space, wall space, gardens and the like. It also doesn't ensure that the apartments will actually fit together.