Three Floors, Three Coop Sizes: What PAES 403 Asks of the Same Twenty Hens

What are the three floors a Philippine standard actually names?

Three, and one clause names them. Here is what each one asks of the same hundred laying hens.

The three floor types of PAES 403:2001 § 5.2, compared along the one dimension its § 6.1 Table 1 measures them by: floor area for the same hundred laying hens beyond 22 weeks.

Row one is quoted from PAES 403:2001 § 6.1 Table 1, the laying row beyond 22 weeks. The standard prints the area for a hundred birds only, so row two is a division by 100 and row three a multiplication by 0.2, both this page’s arithmetic. On the litter share, § 3.4 prints the 60/40 split; the 100% and the 0% follow from the definitions in §§ 3.2 and 3.3, which name no percentage. The last row is §§ 7.5.2.1, 3.4 and 7.5.1.4.

PAES 403:2001 is Agricultural Structures – Housing for Layer Production, written by AMTEC at UPLB under an AFMA project funded by DA’s Bureau of Agricultural Research and adopted by DTI-BPS two years later as PNS/PAES 403:2003. Its § 5.2 lists the floor types; § 3 defines them. Litter type is “type of flooring utilizing the most commonly available materials such as rice hull and rice straw and wood shavings over the cemented floor”. Slotted type is “type of flooring with openings to facilitate cleaning of the droppings”. Slot-litter type is “combination of slotted and litter type flooring wherein slats cover 60% of the total floor area and 40% is covered with litter.”

Read § 3.2 once more and the frame most keepers arrive with shifts. The litter goes over a cemented floor. PAES 403 § 5.2 lists three floors and puts a slab under the only one that holds bedding; PNS/BAFS 312:2021 § 3.10 defines litter as material “on the floors of hen housing systems” and leaves the floor underneath undescribed. Ang lupa sa bakuran, kung saan nakatayo ang karamihan ng manok sa bansa, sits outside both classifications: no area row, no depth, no replacement interval written for it.

So what does a keeper on that lupa read instead? The nearest readable rule is PAES 403 § 3.2’s litter type, which puts the litter over a cemented floor, and the cement is the half a dirt floor is missing.

One consequence before you read on. The coop-size calculator here takes a bird count and hands back an area, with no floor-type input, so it answers a narrower question than the grid above. The coop pillar and the space-per-bird page both work from the per-bird minimum; this page works from the column beside it.

Bakit mas malaki ang sahig kapag litter ang pinili mo?

Take the laying row across. 17 m² per 100 birds on litter, 9 on slats. Subtract and divide and the litter floor asks 88.9% more, for the same hen at the same age in the same standard. Iisang manok, iisang table. Ang pinagkaiba lang ay kung ano ang tinatapakan niya.

The gap is wider before they lay. PAES 403 § 6.1 Table 1 carries a growing row too, 7 to 22 weeks, where the litter floor is 14 m² per 100 birds against the slotted floor’s 6. That is 133.3% more floor on litter than on slats, against 88.9% at laying age. The pullet stage carries the larger penalty and the laying stage narrows it, which is the opposite of what a keeper sizing for adult birds would guess.

That table is a minimum floor area, nothing more: § 1 covers “the minimum requirement for layer production”, and the welfare argument belongs to another kind of document. The typhoon page works through what force the PAES series carries in Philippine building practice.

The comparison that makes the spread strange sits one document over. PAES 402:2001, Housing for Broiler Production, is the same bureau, the same AFMA project, the same year. Its § 5.2 classifies broiler floors too, into slotted and solid, and its § 6 Table 1 gives one figure covering all of them: 6.25 m² per 100 birds at four weeks and below, 12.50 above, which is 8 birds to the square metre for the older ones. One bird, one table, one number per age. The layer gets three.

Where do those three floors stand against PNS/BAFS 312:2021?

The cage-free code came twenty years later, from a different bureau, and its § 5 c) says an owner building a layer house “may also refer” to the PAES series for structural design. It names no PAES number, and may is the weakest word in the clause. PAES 403 is the one it would land on. Line the three rows up against it anyway.

Section 6.2 reads “The space requirement should not be less than the following: a) 0.14m2/bird for single-tiered housing; and b) 0.1m2/bird for multi-tiered housing.” Against it the litter row wants 21.4% more floor and the slotted row sits 35.7% below. The middle row lands on 0.14 exactly. Two bureaux, one pointing at the other’s series without naming a number in it, and the slot-litter floor of 2001 comes to rest on the cage-free minimum of 2021 to the second decimal. Coincidence is the honest word, and it is still the most useful number here.

Then the litter clause, § 6.4.1 complete:

“The usable space in all hen houses should comprise of at least 250 cm2 of litter per hen and should at least occupy one-third of the ground surface.”

Read the second half as attaching to the litter, so that the litter covers at least a third of the ground surface. That is a reading and is stated here as one. The alternative, that the usable space covers a third of the ground surface, is vacuous in a single-tier house, where usable space is the ground surface. The pillar reads it the first way too. On that reading the slot-litter floor’s 40% clears the one-third bar by 6.7 percentage points, and each hen stands on 560 cm² of litter where the same sentence asks for 250.

And the clause that puts slats on the permitted list, § 6.4.3, which the pillar’s own table of § 6.4 leaves out:

“Where slatted areas or mesh floor is used, it should provide the following: a) adequate support for inspections to be carried out; and b) minimum of 1m depth for the build-up of droppings underneath.”

A cage-free standard that permits slats, and prices them at a metre of air. Note what the metre buys: the build-up of droppings underneath.

Saan ba talaga napupunta ang dumi?

Nasa ilalim ng sahig nakatago ang buong argumento. Ang 88.9% na agwat sa pagitan ng 17 m² per 100 birds sa litter at 9 sa slats ay tungkol sa imbakan at wala sa ginhawa ng inahin. Kada floor type ay may sariling paraan ng pag-iipon ng dumi.

Start with what the birds produce. PAES 414-2:2002 Annex B, Daily manure production, is the table both PAES 402 § 9 and PAES 403 § 9 hand the waste to, so it belongs to the same family of documents. Its layer row: 0.09 kg a day, 0.0001 m³ a day, 0.02 kg of that as total solids, 74.80% water. The row is stated at a 1.79 kg bird. Mas magaan diyan ang native o dual-purpose na inahin sa bakuran, kaya ceiling ang bawat numerong susunod at hindi sukat ng manok mo.

Twenty hens, one 45-day cycle. 81 kg of wet manure, 18 kg of it solids once the water is out, and 0.09 m³ by volume, which is the figure a pit under slats has to swallow. Watch those digits. The 0.09 m³ is one cycle of volume; the 0.09 kg in the row above is one hen’s wet manure in a day; the 0.09 m² in the table is one hen’s slotted floor. Same two digits, three different measurements.

Ngayon, sa dalawang sahig. Ang slotted floor para sa 20 inahin ay 1.80 m². PAES 403 § 7.5.1.4 raises it at least 900 mm off the ground on posts at least 200 mm across. 1.80 m² times 0.90 m is 1.62 m³ of pit, and dividing that by one cycle gives 18 cycles before it fills. Mahigit dalawang taon bago mo iyon hukayin. Both cycle counts on this page are floors. Section 7.5.1.4 states 900 mm as a minimum and PNS/BAFS 312 § 6.4.3 b) states 1 m the same way, kaya mas mataas ang itayo mo, mas marami ang kasya.

Ang litter floor ay higaan at hindi hukay. May 50 mm hanggang 100 mm na ipa sa ibabaw ng 3.40 m² na semento, and PNS/BAFS 312 § 6.4.4 b) recommends replacing it every 45 days or whenever necessary, which is a recommendation and not a requirement. Isang cycle. Kaya bawat 45 araw may 81 kg na basang dumi at ipa na ilalabas mo, at may bagong 17 kg hanggang 34 kg na papasok. Iyan ang binili mo nang lumaki ang sahig mo mula 1.80 m² tungo sa 3.40 m²: mas kaunting trabaho sa loob ng dalawang taon, kapalit ng mas malaking bakuran.

This arithmetic declines to do two things. The 81 kg and the 0.09 m³ stay whole on a slot-litter floor, unsplit between the slats and the litter, because how hens distribute droppings across two surfaces is unmeasured, and a 60/40 area split is a poor proxy: birds crowd the feeders, the drinkers and the perches. Pit figure and bed figure are both computed on the whole flock, and both are upper bounds on a mixed floor. The second thing is that it stops at volume. What comes up through a floor from a full pit belongs to the predator page and its apertures.

Then the 100 mm nobody notices. PNS/BAFS 312 § 6.4.3 b) asks for a metre under the slats; PAES 403 § 7.5.1.4 asks for 900 mm. 11.1% more clearance in the cage-free clause, on the same 1.80 m² floor for the same 20 hens. In storage that extra 100 mm takes the pit from 18 cycles to 20, or 90 more days. Ang halaga niyan sa pagtatayo ay ilang pulgada ng poste, at nasa materials page ang bilang ng kahoy at semento.

Why does the 250 cm² everybody quotes never bind?

Every summary of the cage-free code quotes one figure out of § 6.4.1: 250 cm² of litter a hen. Work the sentence it sits in and it is the smaller of two requirements, and the smaller of two requirements is decoration.

At § 6.2’s own single-tier minimum of 0.14 m² a bird, one third of the ground surface is 466.7 cm² a hen. The clause in the same sentence asks 250. The one-third requirement is 1.87 times larger, so that is the clause doing the work while the smaller one takes the citations.

The two agree at exactly one ground area: 0.075 m² a bird, where 250 cm² is a third of 750 cm². That sits below both minima § 6.2 states, 0.14 m² single-tier and 0.1 m² multi-tier. So in any single-tier house built to the code’s own space clause the 250 cm² figure is dominated by the sentence it shares, and it never binds. It would start binding only in housing more crowded than § 6.2 permits.

This corrects a reading and leaves the document alone. Both clauses stand; what changes is which one a keeper sizes a litter area from. Take 466.7 cm² a hen as the working figure at 0.14 m², or 560 cm² on a slot-litter floor. Section 3.17 adds the other half of the correction: usable space “excludes nest areas and any outdoor area, if applicable”, so the nest boxes and the run stay outside the sum entirely.

Kung ipa ang ilalatag mo, gaano kalalim?

Section 6.4.4 c) of the cage-free code asks the litter to “provide sufficient depth for dilution of feces” and states no depth. Here is the whole clause, all six items, of which the pillar prints only b):

“The litter should: a) be made of suitable material and particle size; b) be managed to maintain it in a dry and friable condition (recommended to be replaced every 45 days or whenever necessary); c) provide sufficient depth for dilution of feces; d) allow hens to dust-bathe and forage; e) be managed hygienically; and f) be stored in dry, hygienic, and rodent-proof premises.”

Nasa PAES 403 § 7.5.2.1 ang lalim, at doon mo makikita: “Litter material shall be at least 50 mm - 100 mm deep over the cemented floor. Around the cemented floor, there should be solid wall with a height of 600 mm to retain the litter.” The depth is a shall and the retaining wall is a should, inside one clause.

With a depth in hand the dilution clause can be weighed. The IRRI Rice Knowledge Bank puts the specific weight of uncompressed rice husk at “about 100 kg/m3”. That page treats husk as fuel and as a soil amendment and says nothing about poultry bedding, so it is read here for a physical property alone. On the 3.40 m² litter floor 20 hens need, a 50 mm bed of ipa weighs 17 kg and a 100 mm bed 34 kg.

Set the 18 kg of solids from one cycle against those two beds. At 50 mm the ratio is 1.06: the droppings outweigh the bedding they are supposed to be diluted into. At 100 mm it is 0.53, and the bed takes on about half its own weight again. It is the 50 mm bed that roughly doubles. Dilution is accurate at one end of the band and generous at the other, and § 7.5.2.1 permits both without distinguishing them. Fifty millimetres of ipa is the whole difference. Sa brooder ay ibang usapan ang lalim, at nasa brooding page ang mga figure para sa sisiw.

Ipa itself carries two checks rather than two claims. The composting standard the layer house hands its waste to, PAES 414-2, tabulates carbon-to-nitrogen ratios for 29 materials, cattle manure with straw at the top and wood chips at the bottom. Rice straw is there at 48 to 115, saw dust at 300 to 723, wood chips at 100 to 441, poultry manure as henhouse litter at 12 to 18. All 29 rows were read, and rice hull is in none of them, so the material PAES 403 § 3.2 names first as a layer-house litter is absent from the table its own § 9 sends that litter to.

And the price. The fifteen feed-ingredient series here come off the DA-BAI weekly board, which prices feed, and ipa is bedding. Two checks came back short: PSA’s price situationer returned an HTTP 403 on 23 August 2026 and philrice.gov.ph did not resolve. Both are unchecked, which is not the same as ruled out. Marketplace listings do carry a per-sack figure for ipa, and a marketplace post is an anonymous, undated number with no method behind it, which is why none appears here. The gaps register is where a hole of this shape gets a number.

What usually goes wrong

1. The mistake: Sizing the house from PNS/BAFS 312:2021 § 6.2’s 0.14 m² a bird, then laying a full litter floor on it.

   Do this instead: A litter floor is PAES 403:2001 § 6.1 Table 1’s widest row at 0.17 m² a bird. Size for 3.40 m² for 20 hens, not 2.80 m².

   The two documents measure different things. 312 sets a cage-free space minimum; PAES 403 sets a minimum floor area that moves with the floor type. The litter row asks 21.4% more than the cage-free minimum.

2. The mistake: Counting the nest boxes and the outdoor run inside the 0.14 m² a bird.

   Do this instead: Measure the floor the hens stand on, and add the nests and the run outside that figure.

   PNS/BAFS 312:2021 § 3.17 defines usable space as the main floor and litter area plus elevated tiers at least 45 cm high, and says it "excludes nest areas and any outdoor area, if applicable".

3. The mistake: Sizing the litter area from the 250 cm² a hen that every summary of § 6.4.1 quotes.

   Do this instead: Use one third of the ground surface: 466.7 cm² a hen at 0.14 m², or 560 cm² on a slot-litter floor.

   The same sentence carries both requirements and the one-third clause is 1.87 times larger at 0.14 m². The two would agree only at 0.075 m² a bird, which is under both of § 6.2’s minima.

4. The mistake: Raising a slat floor 900 mm because that is the figure in circulation.

   Do this instead: Raise it to a metre. The posts get 100 mm longer and the rest of the build is unchanged.

   PAES 403:2001 § 7.5.1.4 says at least 900 mm and PNS/BAFS 312:2021 § 6.4.3 b) says a minimum of 1 m. On a 1.80 m² floor for 20 hens the extra 100 mm is 90 more days of storage, or 20 cycles instead of 18.

Why does the layer get three floor areas and the broiler get one?

Somebody made that choice in 2001 and left the reasoning out. Maybe the layer’s longer stay changes the answer, since a broiler leaves in weeks and a hen stays through 45-day cycles for a year or more. Maybe it is nothing more than the order the two were drafted in. Halo ang karamihan ng bakuran dito: may broiler sa isang sulok at may inahin sa kabila, sa iisang sahig. Neither document answers that, and there is no third one to ask. Pick the bigger of the two figures and you will not be wrong by much.

Questions people actually ask

What is the deep litter system for chickens in the Philippines?

The nearest thing a Philippine document has to a name for it is the litter-type floor in PAES 403:2001 § 3.2, which is defined as a floor "utilizing the most commonly available materials such as rice hull and rice straw and wood shavings over the cemented floor". Section 7.5.2.1 of the same standard sets the bed at 50 mm to 100 mm deep and asks for a solid wall 600 mm high around the cemented slab to hold it in. PNS/BAFS 312:2021 § 6.4.4 b) recommends replacing the litter every 45 days or whenever necessary. On the floor-area side PAES 403 § 6.1 Table 1 gives a laying flock on a litter floor 17 m² per 100 birds, the largest of its three floor types, which for 20 hens is 3.40 m².

How deep should chicken litter be? Show the answer

PAES 403:2001 § 7.5.2.1 states 50 mm to 100 mm over the cemented floor, and it is the only Philippine clause found that gives a depth for a layer house. PNS/BAFS 312:2021 § 6.4.4 c) asks the litter to "provide sufficient depth for dilution of feces" and states no figure at all. The two ends of the PAES band behave differently. For 20 hens on a 3.40 m² litter floor, a 50 mm bed of rice hull weighs about 17 kg at the IRRI Rice Knowledge Bank figure of about 100 kg/m³ for uncompressed husk, and one 45-day cycle of droppings from those hens carries about 18 kg of total solids, a ratio of 1.06. At 100 mm the bed weighs 34 kg and the ratio is 0.53.

Is a slatted floor allowed in a cage-free chicken house? Show the answer

Yes, and PNS/BAFS 312:2021 § 6.4.3 addresses it directly: "Where slatted areas or mesh floor is used, it should provide the following: a) adequate support for inspections to be carried out; and b) minimum of 1m depth for the build-up of droppings underneath." What a fully slatted floor leaves unanswered is § 6.4.1, which asks for at least 250 cm² of litter per hen occupying at least one third of the ground surface. A fully slatted floor carries no litter, so that clause goes unanswered. PAES 403:2001 § 3.4 has a floor type that answers both: the slot-litter floor, slats over 60% of the area and litter over 40%.

How much floor space does a laying hen need in the Philippines? Show the answer

Two Philippine documents answer, and they answer differently because they are measuring different things. PNS/BAFS 312:2021 § 6.2 sets a cage-free minimum of 0.14 m² per bird for single-tiered housing and 0.1 m² for multi-tiered. PAES 403:2001 § 6.1 Table 1 sets a minimum floor area that changes with the floor type: for a laying flock beyond 22 weeks, 17 m² per 100 birds on litter, 14 on slot-litter and 9 on slats, or 0.17, 0.14 and 0.09 m² per bird. The litter row asks 21.4% more floor than the cage-free minimum and the slotted row sits 35.7% below it. PNS/BAFS 312:2021 § 3.17 also excludes nest areas and any outdoor run from the space it counts.

Can chickens be kept on bare ground? Show the answer

Backyard flocks are kept on bare ground all over the country, but neither of the two Philippine documents that classify a layer floor has a row for it. PAES 403:2001 § 5.2 names three floor types, litter, slotted and slot-litter, and its § 3.2 puts the litter one "over the cemented floor". PNS/BAFS 312:2021 § 3.10 defines litter as material "on the floors of hen housing systems" and leaves the floor beneath undescribed. So a keeper choosing between deep litter and slats is choosing between two published specifications, while a keeper on bare ground stands outside both classifications, and the surface underfoot has no published area, depth or replacement interval of its own.