It doesn&a;t make much sense that a house with a 150&h;ft² living room and a 100&h;ft² dining room can accommodate 15 occupants under IPMC table 404.5 when neither of those rooms can accommodate 15 people sitting at tables under IBC table 1004.5. The following table fixes that incongruity.

Occupant count	Minimum area (ft2)
	Per occupant			Total
	Living	Dining	Total	Living	Dining	Total
1	133 + 1/3	0	133 + 1/3	133 + 1/3	0	133 + 1/3
2	66 + 2/3	0	66 + 2/3	133 + 1/3	0	133 + 1/3
3	40	26 + 2/3	66 + 2/3	120	80	200
4	30	20	50	120	80	200
5–∞	25	16 + 2/3	41 + 2/3	125–∞	(83 + 1/3)–∞	(208+1/3)–∞

Demonstration of how this new table makes more sense than the original table:

Occupant count	Minimum area (ft2)
	Original						Improved
	Total			Per occupant			Per occupant			Total
	Living	Dining	Total	Living	Dining	Total	Living	Dining	Total	Living	Dining	Total
1	120	0	120	120	0	120	133 + 1/3	0	133 + 1/3	133 + 1/3	0	133 + 1/3
2	120	0	120	60	0	60	66 + 2/3	0	66 + 2/3	133 + 1/3	0	133 + 1/3
3	120	80	200	40	26 + 2/3	66 + 2/3	40	26 + 2/3	66 + 2/3	120	80	200
4	120	80	200	30	20	50	30	20	50	120	80	200
5	120	80	200	24	16	40	25	16 + 2/3	41 + 2/3	125	83 + 1/3	208 + 1/3
6	150	100	250	25	16 + 2/3	41 + 2/3	25	16 + 2/3	41 + 2/3	150	100	250
7	150	100	250	21 + 3/7	14 + 2/7	35 + 5/7	25	16 + 2/3	41 + 2/3	175	116 + 2/3	291 + 2/3
8	150	100	250	18 + 3/4	12 + 1/2	31 + 1/4	25	16 + 2/3	41 + 2/3	200	133 + 1/3	333 + 1/3
9	150	100	250	16 + 2/3	11 + 1/9	27 + 7/9	25	16 + 2/3	41 + 2/3	225	150	375
10	150	100	250	15	10	25	25	16 + 2/3	41 + 2/3	250	166 + 2/3	416 + 2/3
11	150	100	250	13 + 7/11	9 + 1/11	22 + 8/11	25	16 + 2/3	41 + 2/3	275	183 + 1/3	458 + 1/3
12	150	100	250	12 + 1/2	8 + 1/3	20 + 5/6	25	16 + 2/3	41 + 2/3	300	200	500
13	150	100	250	11 + 7/13	7 + 9/13	19 + 3/13	25	16 + 2/3	41 + 2/3	325	216 + 2/3	541 + 2/3
14	150	100	250	10 + 5/7	7 + 1/7	17 + 6/7	25	16 + 2/3	41 + 2/3	350	233 + 1/3	583 + 1/3
15	150	100	250	10	6 + 2/3	16 + 2/3	25	16 + 2/3	41 + 2/3	375	250	625
∞	150	100	250	0	0	0	25	16 + 2/3	41 + 2/3	∞	∞	∞

In the improved table, as the occupant count rises, the required areas per occupant (1) fall to reasonable nonzero minimums (taken directly from the original table) rather than nonsensically to zero, and (2) progress steadily downward rather than nonsensically zigzagging up and down (except for weirdness caused by the original table&a;s requiring no dining area at all for occupant counts smaller than three).

If you prefer, you can use different numbers, as long as they are no lower than the numbers in the original table. Here are some examples.

Rounding living&h;room size down to multiples of (15 + 7) ft² (one person sitting at a table and one person sitting on a chair without a table under IBC table 1004.5), and dining&h;room size down to multiples of 15 ft² (one person sitting at a table), past 6 occupants (my preferred variant):

Occupant count	Minimum area (ft2)
	Per occupant			Total
	Living	Dining	Total	Living	Dining	Total
1	133 + 1/3	0	133 + 1/3	133 + 1/3	0	133 + 1/3
2	66 + 2/3	0	66 + 2/3	133 + 1/3	0	133 + 1/3
3	40	26 + 2/3	66 + 2/3	120	80	200
4	30	20	50	120	80	200
5	25	16 + 2/3	41 + 2/3	125	83 + 1/3	208 + 1/3
6	25	16 + 2/3	41 + 2/3	150	100	250
7–∞	22	15	37	154–∞	105–∞	259–∞

Another alternative that smooths the progression even further: Minimum living+dining area = 200 ft² × &cbrt;(occupant count ÷ 3), without rounding. (In words: The minimum living+dining area starts at 200 ft² for 3 occupants, and from there scales up or down with the cube root of occupant count. For example, a house with twice as many occupants will require, not twice as much living+dining area, but only 26 percent more living+dining area.) For one or two occupants, the minimum area is all living room; for three or more occupants, it&a;s 3/5 living room and 2/5 dining room. (The numbers given in the following table are rounded for simplicity.) This matches the original progression very well, and it is very arguable whether this progression still runs into absurdities at high occupant counts. (Where the original progression assumes that a dining room need never accommodate more than six people sitting at tables even in a gigantic mansion, this progression assumes that a dining room need never accommodate more than about 3.70 people sitting at tables per &cbrt;(occupant count): a 100&h;occupant mansion still has a larger dining room than a six&h;occupant house, but the increase in area is much slower than linear. Perhaps all the occupants not accommodated by the dining room are servants.)

Occupant count	Minimum area (ft2, rounded) Do not use these rounded numbers in design.
	Total			Per occupant
	Living	Dining	Total	Living	Dining	Total
1	139	0	139	139	0	139
2	175	0	175	87	0	87
3	120	80	200	40	27	67
4	132	88	220	33	22	55
5	142	95	237	28	19	47
6	151	101	252	25	17	42
7–∞	159–∞	106–∞	265–∞	23–0	15–0	38–0