Field exercise: measure an existing house and calculate its flock size in the heat

This lesson is part of Designing and building a poultry house specialisation. It opens to every registered student, from free registration. Levels 1 to 5 and the tracks remain readable by everyone.

How many chickens can your house hold in March? Most farmers answer with the figure they have always used, or with the neighbour’s. The right answer is measured with a tape, in one hour, and calculated in ten minutes. This exercise has you measure the dimensions of your own house (or of the one you want to buy or rent), fill in a survey sheet, and derive from it the flock it can carry at 5 per m² in the hot period, with the corrections that would change that figure. It is the exercise a technician does before giving an opinion on a house.

• ✓Measure with a tape the twelve useful dimensions of an existing poultry house, in the right order and at the right places
• ✓Fill in the survey sheet (table) and compare it with the reference dimensions of the 8 m house
• ✓Calculate the usable area, the hot-period flock at 5 per m² (manufacturers’ benchmark 8 to 10), the opening ratio and the air volume
• ✓Read the result: flock to order, corrections to make, and what each correction would change

1. Equipment and preparation (day 0)
2. The procedure: twelve dimensions, in order
3. The survey sheet
4. Reading the sheet: the five calculations
5. From survey to decision, and the mistakes of the exercise
6. What the exercise gives you for what follows

• •Twelve dimensions surveyed inside, at three points: width, length, lobby, low wall, eave, ridge, overhang, ridge opening, orientation, obstacles, posts, slab; plus smoke and 2 p.m. temperature.
• •Usable area = width × usable length (without the lobby); hot-period flock = area × 5 (NEXTEKCI advice; manufacturers 8 to 10 in closed houses): 7.6 × 26.5 = 201.4 m² → 1,000 broilers.
• •Opening ratio = (eave − low wall) × 2 × usable length ÷ usable area, to be kept at 40-50%: here 42%, 50% with a 0.5 m low wall.
• •Prudence rule: − 1 bird per m² as long as the ridge is closed or the overhang is less than 1 m: 800 instead of 1,000.
• •The survey decides: how many to order (real state), what to correct first (easy dimensions furthest off), buy or rent (orientation, width, siting, slab).