The Neighbours Call It The Hilton
The Gist: Willie and Sally Bosch run 250 cows at Creaming It farm in Carterton, Wairarapa. Their hybrid composting barn went up with Numat Construction and was finished in August 2025. It has now done a full season and a first winter, and Willie says he would build another one tomorrow.
We went back to see how it is actually working. Not on open day, with sixty people walking through it. On a normal winter morning, with heifers standing in it and a ripper sitting outside.
The neighbours have given it a name. One of them told Willie his cows looked good in the Hilton the other night, and Willie is not arguing the point. Compared to standing outside under a tree, he reckons that is about right.
What came out of the conversation was bigger than the barn. Willie has pulled calving forward ten days. He doubled his round speed in the autumn. He went through a week with 170mm of rain and did not think twice about it. None of that was the plan when the poles went in.
Below is the video and the full interview, then everything he told us about running it. The bedding volumes, the ripping routine, the airflow answer, the sawdust problem, and the one thing he would change.
Watch: One Year On, In The Barn
What Is In Here
The Full Conversation
Below you’ll find the complete audio recording of the interview. It runs through the main points in detail and includes the full context that didn’t make it into the written summary.
Hit play to listen through at your own pace.
Quick Facts
The barn as it stands after one full season and a first winter.
The Barn
Farm: Creaming It, Carterton, Wairarapa
Owners: Willie and Sally Bosch
Herd: 250 cows
Barn size: 82.8m long by 14m wide, 12m centre plus overhangs
Design: Hybrid composting barn. Feed face both sides, 12m central loafing and compost area
Roof: Mono-pitch, 5 degree slope
Built by: Numat Construction
Key materials: H5 timber poles, NuSpan rafters, mesh curtains
Cost: $350,000 including earthworks, concrete, curtains and feed face
The Compost Bed
Bed depth: Close to one metre
Starting mix: Roughly half woodchip, half sawdust
Current mix: Weighted towards sawdust, since only sawdust has been added since
Bed temperature: Around 55 degrees at last measurement
Ripping depth: About 800mm on the deep pass
Method: Double rip. First pass shallow at around 400mm, second pass straight down
Ripping frequency: Every second day this winter. Previously twice a week
Time to rip: About ten minutes, roughly four runs
Tractor: Four wheel drive needed. Willie reports no real wear or tear
Bedding Top-ups
Volume per season: Around 200 cubic metres, in two lots of 100 to 120
Timing: First top-up October to November, second in March
Delivery: Four truck and trailer loads per top-up, two dropped at each end
Where it goes: Along the feed face only, not across the middle
Method: Scooped along the face with the bucket, roughly one bucket per section
The First Winter
Stock wintered: Heifers, in from 1 June
Daily routine: Out for grass in the morning, in around midday, in every night
Grass offered: About four kilos a head in the paddock
Supplement: One bale of baleage a day, plus maize
Winter pasture used: Five to six hectares across the whole winter
Wet weather: A week of around 170mm of rain came through with no paddock damage
What Changed On Farm
Calving start: Pulled forward ten days, from 1 August to 20 July
Mating start: 22 July, a week earlier than previous seasons
Mating length: Unchanged at ten weeks
Autumn round: Went from a 30 day round to a 65 day round
Mastitis: No increase on previous seasons
Cow condition: Holding through winter rather than the usual autumn push to put weight on
Production: Up on the previous season
Downtime
Unused period: Mid December to late February. Nothing went in it, no ripping
Restart: Cows back in late February. After roughly three sessions and six hours of use, ripping restarted and the bed was steaming again inside a week
Inside The Build
A Year On
The barn went up in 2025 and was in use for calving that spring. On 9 October, over sixty farmers walked through it at the open day, asked Willie everything they could think of, and left with a fair idea of what a hybrid composting barn costs and how it works. We wrote that up at the time, including the full cost breakdown and the open day Q&A. Read it here: Composting Barn: Real Results After First Season
What we had then was a barn that had done a spring and a summer. It had been used for calving, then settled into life as a feed pad, a couple of hours a day. What it had not done was a winter.
That is the gap this piece fills. Willie has now wintered stock in it, run it through the autumn as herd housing, walked away from it for two and a half months over Christmas, and started it back up again. A full year of it, in every season the Wairarapa could throw at it.
He is also still getting phone calls. The open day video is the most watched on our channel at 16,000 views, and it keeps resurfacing. Willie had messages from blokes who saw it at field days, one from the builder who put the barn up, and a local farmer coming down this month to see it running. His words on that: everyone is always asking so many questions, so he is just trying to pass on the learnings.
So we went back in the middle of winter, with heifers standing in the barn and a ripper parked outside, to get the rest of it.
The First Winter: How He Is Running It
The heifers came in on 1 June. This is the first winter the barn has been used for wintering, and Willie went into it wanting to see what it was actually like.
The routine is simple. They go out for grass in the morning, get about four kilos a head, and come back in around midday. If the weather is rubbish they come in earlier. Every night they are inside.
On a fine day he will leave them out a bit longer, but there is not much out there to hold them anyway. Across the whole winter he expects to go through five or six hectares, and that is grass only.
Inside they are getting a bale of baleage a day plus maize.
He is only feeding one side of the barn, and there is a reason for it. The baleage binds up the ripper. He noticed it inside the first week of feeding it, and it is enough to catch, build a lump, and therefore stops the rippers turning the woodchip bedded pack. Feeding one side means he can drag that material across to the middle and work it in, rather than dealing with it down both faces.
“You get a bit of this and then that catches, and before long you’ve got a lump. It just binds.”
His fix is to lift the rippers, keep going, and drop them back down. Not a problem, just a thing you learn.
Feeding one side also means the barn is running well under what it could carry. Feed both faces and he is looking at 100 plus cows in there. He is already talking about doing more next year.
When a cold southerly comes through, the decision gets easier rather than harder.
“You just feed out another bale of baleage and chuck some more maize out to them, and they’ll be happy sitting in here.”
Settling Them In
The heifers took to it straight away. First night they were locked in, and they were still there the next morning.
“Yeah, it was fine. From the first night, you just locked them in and they’re still here the next morning.”
They are young stock, so anything new gets a reaction. One night a bit of solid plastic was flapping around at the end of the barn and Willie reckons they would have been down that end all night keeping an eye on it. He is relaxed about it, because that is what heifers do.
“They’re just teenagers really. There’s so many things changing in the environment at this age.”
What Happens Next: Springers, Then Milkers
From the middle of next month the springers start coming home and join the heifers. Willie sees the barn doing a job here that has nothing to do with shelter, which is easing heifers into the herd.
“You either introduce your cows into your heifers, or you introduce your heifers into your cows.”
Going from their own mob into the milking herd is a big shift for a heifer. Doing it in small groups, as springer mobs come home week by week, takes the heat out of it. Alongside that they get run through the yard and the cowshed a few times so the plant is not a surprise either. They have already been through once for tagging.
“Come calving, they literally just walk up and stand there. None of this stuff of running up and down.”
Once the milking herd builds to 40 or 50 cows, the plan is to split the barn. Springers down the back, milkers at the front, and different feed down each face.
Springers would be on hay and a bit of maize. Milkers on maize and PK, or something similar. That is the point where both sides of the barn come into use.
Managing The Compost Bed
Willie rips the bed every second day this winter, and it takes him about ten minutes.
That is the short version. The detail underneath it is where most of the questions land, because how you rip is what decides whether the bed composts or just sits there.
The Double Rip
He never does it in one pass. Every rip is two passes, and the first one is deliberately shallow.
First pass sits around 400mm and does nothing more than break up the top. Second pass goes straight down, about 800mm, and lifts the lot.
“Always double rip it. Your first pass, just don’t go as deep. That’s all it comes down to.”
The reason for the shallow pass is pull. A compacted bed, especially where the baleage has bound it up, is hard work to drag a ripper through. Breaking the top first means the deep pass flows instead of catching and building lumps.
The rippers themselves have a wide foot on them, and Willie thinks that is doing real work. It lifts the bed right up from the bottom rather than just cutting through it.
“I think that’s why we’re getting such a good compost going as well. Ripping it deep, that’s probably the secret.”
Air from below is the whole point. That is the part he keeps coming back to.
The Ripping Routine
Frequency: Every second day this winter
Previously: Twice a week, when the barn was running as a feed pad
Passes: Two. Shallow then deep
First pass depth: About 400mm
Second pass depth: About 800mm
Runs to cover it: Around four
Time taken: About ten minutes
Tractor: Four wheel drive required
Wear and tear: None worth noting. Willie compares it favourably to ripping out in the paddock
He is honest that every second day is more than he strictly needs right now. The heifers are in about twelve hours a day and there are not many of them, so the bed is under low pressure. He reckons he could get away with every third day.
“I know you probably could leave it, but why not just go rip it.”
The one exception is the fed side. That is where the animals stand while they eat, and it compacts. Ripped yesterday and it will be solid again tomorrow. He does not rip right to the edge of the feed face, stopping short of it.
How You Know It Is Working
Last time Willie measured the bed it was sitting around 55 degrees. He has not measured it recently, and he does not need to, because the barn tells him.
Even a couple of hundred millimetres down, before you get anywhere near ripping depth, you can feel the heat in it.
“If you try to dig a hole after I rip it, you’ll just dig it in with your boots. It’s so soft.”
How The Bed Has Mixed
The bed started as roughly half woodchip and half sawdust. Since then only sawdust has gone in, so the balance has shifted.
The chip was sitting at the bottom to start with. A year of ripping has mixed it right through.
“We did have the chip at the bottom, but it’s sort of quite evenly mixed now. It’s not like when I rip you just see a whole lot of chips coming up.”
The chip is slow to break down and Willie expects it to be in there a long while yet. That is not a problem. It is the sawdust doing the composting work and the chip holding structure.
Two And A Half Months Off, And It Fired Straight Back Up
From mid December to late February, the barn sat empty. Nothing went in it. He did not rip it once.
“We were finished. We’ll just leave it and see.”
Cows went back in at the end of February when the turnips finished up and silage started again. After roughly three sessions, about six hours of cows standing on it, he started ripping again.
“Within a week it was starting to steam up again and carry on.”
He was surprised by that, and it is worth knowing if you are looking at a barn and wondering what happens over a dry summer. It does not take much to get it going again.
Bedding Top-Ups: The Real Numbers
Across the first season Willie added around 200 cubic metres of sawdust to the bed, in two top-ups.
First one went in around October or November, after starting in August. Second one went in in March. Each top-up is roughly 100 to 120 cubic metres, which comes in as four truck and trailer loads.
“That’s only four truck loads. Not a unit load, two unit loads pretty much.”
Two loads dropped at the front, two at the back, and he moves it from there with the bucket.
The Top-Up At A Glance
Volume per season: Around 200 cubic metres
Number of top-ups: Two
Volume per top-up: 100 to 120 cubic metres
Timing: October to November, then March
Delivery: Four truck and trailer loads per top-up
Drop points: Two loads at the front, two at the back
Placement: Along the feed face only
Method: One bucket per section, spread along the face
Material: Sawdust only. No further woodchip has gone in
Why Only The Sides
The top-up is not about the whole bed. It is about the strip where the animals stand to eat.
That is the part that wears down. The cows come up to the feed face, stand in the same spot, and the bed chews out underneath them. The middle of the barn looks after itself, because ripping moves material around anyway.
“I don’t target areas. The main reason we top up is because of that front part there.”
Willie tips a bucket into each section and it comes back up to height. Within a few days of the cows standing on it, it settles back down, but it is solid again rather than dished out.
The reason it matters is feed height. There is a science to how far a cow should have to reach down to eat, and if the bed drops away too far she is working for it. Get down to the fourth board and the heifers start to struggle to get their heads over.
“It got down to the fourth board. It’ll start to get down to there.”
The Grader Blade Experiment That Did Not Work
Before the first top-up, Willie tried to solve it with what he had on hand. He used a grader blade to pull sawdust from the middle of the barn out to the feed face.
“It actually dished it right out. I think I might have done it a bit too much, without any real results, because next time I ripped it it sort of just came back in anyway.”
Worth knowing if you are looking at doing the same. It is not that it cannot be done, it is that the ripping undoes it. He went and got more sawdust instead, and that was the end of the problem.
“The first time it was like, oh, what do I do now. I’ll just grab some more sawdust. No problem.”
Topping Up Is Also Feeding The Compost
The top-up does two jobs, and the second one is the one people miss.
Sawdust is carbon. Every time the bed composts, it burns carbon. Keep aerating a bed and eventually there is nothing left to burn, and it stops cooking.
“You’re adding air into it, and eventually you’re going to run out of carbon. That’s when it doesn’t compost anymore.”
Adding sawdust twice a season is not just filling a hole at the feed face. It is putting the carbon back.
“Me adding sawdust is probably helping that. We’re just actually feeding it.”
Willie’s read on the economics of that is short.
“You’re always gaining on it anyway.”
Top Up, Or Dig It Out And Start Again
There is another farmer running a barn system who got about two years out of his woodchip before pulling the whole lot out and starting fresh. His advice afterwards was not to do it that way again.
“He said if he’d do it again, he’ll probably only do half. Take part of it out, add sawdust to it, and then straight away it’s composting again.”
Digging the whole bed out means restarting the process from cold. Taking half out leaves you with live material to inoculate the new stuff.
That system is set up differently, with a feed pad beside the barn, so the cows use the bed more for loafing than feeding. Different pressure on the bed, different lifespan.
Willie’s own plan, if his bed ever stops composting, is the same half measure.
“We’ll just dig out the top 300 or something, add a bit of sawdust to it, and then just start adding stuff to it.”
A year in, he has not needed to.
Feed Into The Cow
Asked what the biggest learning has been, Willie did not go to shelter, or effluent, or cow comfort. He went to feed.
“Probably the biggest one would be just being able to get more into the cow. What we’re putting into the cow, the cows are actually eating.”
That is the whole thing in one sentence: feed put in front of an animal on a compost bed gets eaten.
“It was always maize and fine chop and no wastage. That has been awesome, knowing that what we’re putting in front of the cow, they’re eating it.”
The only wastage he mentions all interview is a bit on the baleage, and that only started when the heifers came in this winter.
Maize All The Way Through
The rule outside is that you feed maize until it gets wet, and then you stop.
“You basically can feed maize up till it gets wet, and then you stop feeding maize. Whereas now you could just go all the way through.”
Put maize out in a wet paddock and it gets trampled. Put it under a wire and you still waste it. That is not a maize problem, it is a surface problem, and the barn removes it.
Willie is now predominantly feeding maize, which he says he would not do if the cows were out in the wet. That change is doing a lot of the work behind the production and condition results further down this page.
There Is Always Something In Front Of Her
The pattern he describes is one most farmers will recognise the opposite of. A cow finishes what is in front of her, goes and stands in a corner, then starts walking and looking for more. That walking is what damages grass.
In the barn, she eats, goes and lies down, comes forward and has another look.
“There’s always something for the animal to eat, so she can go sit down, and she’ll just come forward here and have another look.”
He gives an example from a frosty morning this winter. He did not get the heifers out until about half nine. By six that evening he thought there must still be feed left in front of them. Came back at nine and they were hooking into it again.
“Sometimes you come here and you think they’re not going to finish that.”
Keeping the animal full, all the time, is what he thinks is behind the rest of it.
Feeding Less To Achieve More
This is the part worth sitting with. Willie reckons a cow in the barn needs materially less feed offered than the same cow at the runoff, because she is not spending energy staying warm and walking around.
“Up at the runoff we’re offering our cows sort of 14 to 15 kilos a day. Whereas in a situation like this, they’re not going anywhere, they’re not cold, they’re just standing here. You probably could get away with eight or ten.”
That is his estimate rather than a measured trial, and it should be read that way. He has not run the two side by side. But it is a working farmer’s read after a full season of doing both, and the direction of it is not in dispute.
Offered Feed, Runoff Against Barn
Runoff, offered per cow per day: 14 to 15 kilos
Barn, Willie’s estimate: 8 to 10 kilos
Wastage, paddock: Trampling, feed walked in, worse in wet
Wastage, barn: Minimal. Some on baleage only
Maize in wet conditions, paddock: Stops being viable
Maize in wet conditions, barn: Fed right through
Energy spent by the cow, paddock: Walking, standing in wet, keeping warm
Energy spent by the cow, barn: Little. Not cold, not moving
The Honest Catch
The discussion group in April raised the one real limitation, and Willie repeated it without being asked. Feeding this well only works if you can grow or buy the feed to do it.
“We’re not growing enough grass out on the farm either. Tonnages down. So that sort of screws it a bit with the amount of feed that we’re poking into them.”
He is dealing with it by regrassing. About half the farm has gone into new grasses so far. The barn has actually made that easier, because he can now spray up whole paddocks and target areas properly rather than patching damage with an annual after every wet event.
“Back before this you’d go with the drill into certain areas and say, I better drill up this patch. Now you’re doing full paddocks, targeting areas. You can actually do what you want to do.”
The group also told him he had turned into a system five farmer. He says that surprised him.
“Back in the day it used to be looked down on. Give another five years and you’ll be broke. These days, you start feeding two loads of silage a day and straight away you’re a system five farmer.”
A few in the room went home wondering the same about themselves.
Production and Cow Condition
Production is up on last season, and Willie will not hand the barn all the credit for it.
“We’re up quite a lot this year in their production. I mean, we had a good season anyway.”
That is worth reading twice, because it is the sort of qualification you rarely get in a case study. It was a good season in the Wairarapa regardless. What Willie does put down to the barn is the feed he was able to use.
“A lot of it will be to this, and the type of feed we could use. We’re predominantly maize, which you wouldn’t do if it was just wet out.”
The mechanism is the one from the section above. Maize fed right through the wet, no trampling, no waste under a wire, and an animal that always has something in front of her. The production lift follows the feed, and the feed follows the surface.
The Autumn That Did Not Turn Into A Scramble
The condition story is clearer than the production one, and Willie is more definite about it.
The usual pattern is that you get to March, start looking hard at condition score, and spend the rest of the autumn and winter trying to poke as much feed into them as you can.
“Normally you get to sort of March and you start looking hard at condition score, trying to poke as much feed as you can into them through winter.”
That did not happen this year.
“Now it’s probably more holding their weight, or we might have gained a bit. It’s not like there’s a huge push to get this weight on them.”
The cows dried off in better condition and it was a lot nicer. No catch-up, no scramble, no wondering whether they will get there before calving.
“They dried off a lot nicer, better condition.”
His summary of it is the line that matters most in this section.
“Overall, your whole season is different.”
Control Over What Goes In
The reason the condition work got easier is control. In the barn he decides what she eats. Outside, the weather decides.
That is the same point arriving from a different direction. Condition score is a feeding outcome, and the barn is what made the feeding consistent.
Pasture: The Damage That Did Not Happen
A week of around 170mm of rain came through last season, and Willie says you do not notice it.
“We had a week there, we got about 170mil rain, and you don’t notice it. It doesn’t even worry you.”
That is the whole section in one line, but the mechanism underneath it is worth spelling out, because it is not just about getting cows off wet ground. It is about getting them off before the damage starts.
Taking Them Off Before, Not After
The damage pattern he describes will be familiar to anyone who has wintered on grass. A mob finishes its break, stands in a corner for a while, then starts looking for more feed and walking. The walking is what wrecks the paddock, and it happens after the feed has run out.
“As soon as the cows finish, they go stand in a corner, and then they start looking for more food and they start walking around and damaging grass.”
Before the barn, the answer was to shift them again, which means chewing through more feed than you meant to.
“You’d just leave them out in the field, and you’d probably just move them more, so you just chew through more feed.”
Now they get their feed of grass and come off.
“You don’t have any of that, because you take them off before that happens.”
The barn is not a wet weather shelter in the way he uses it. It is a timing tool. The cows come in on a schedule rather than in response to a mess that has already started.
This Winter’s Pasture Use
Winter grass area used: Five to six hectares across the whole winter
Grass offered per head: About four kilos a day
Time out on grass: Mornings only, in by around midday, earlier in bad weather
Nights: In the barn, every night
Damage this winter: None reported. The gateway is a bit dirty
“We’ve only gone through a couple hectares and no damage. The gateway’s a bit dirty, but that’s just the gateway. It’s grown again.”
The Bag Of Grass Seed Maths
This is the part Willie is most direct about, and it is the cost that never appears on a budget line.
Before you build something like this, the reasoning goes that a bag of grass seed is cheap. You do some damage, you throw a bag at it, it fixes itself.
“You always talk about a bag of grass seed being cheap. You do some damage and you’re like, I’ll chuck a bag of grass there, that’s cheap, it’ll fix it. But yeah, at the end of the season, you use a bit, a few bags of grass seed.”
It is never one bag. It is a few bags, every season, plus the drilling, plus the paddock out of the round while it comes back, plus the feed you did not grow in the meantime.
The change is not that he stopped sowing grass. He is still putting new grasses in, and has done roughly half the farm. The change is that the sowing is now planned rather than reactive.
“Back before this, you’d go with the drill into certain areas and say, I better drill up this patch. I remember when we had this rain event, this half paddock got smashed, we’ll redrill this, chuck an annual or a two year grass in. Whereas now you’re doing full paddocks, spraying up, targeting areas. You can actually do what you want to do.”
An annual thrown at a smashed half paddock is a patch. A sprayed and drilled full paddock is a pasture decision. The barn is what moved him from one to the other.
Calving Pulled Forward Ten Days
Calving used to start on 1 August. It now starts on 20 July.
Willie did not build a barn to change his calving date. He built it to feed cows better and get them off wet paddocks. The calving decision came later, and it came because the barn removed the reason not to.
Why The Old Date Was Never Really Safe
The problem with an early calving date has never been the date. It is what the weather does to it.
“Even sometimes first of August was too early. You get a wet period and it’s just, any date is too early.”
That is the trap. You can set 1 August, and a wet fortnight makes it the wrong call. You can set 10 August and lose the days at the other end. Without somewhere to put them, every date is a gamble on a forecast you do not have yet.
The barn takes the weather out of the decision.
“Now that you’ve got somewhere to go, it can be wet out there. You just chuck them in here and you’re not doing any damage on the farm anyway. Everything’s comfortable.”
He Moved It In Two Steps
This was not a jump. Last season he pulled the start forward a few days, to around 27 or 28 July, and watched what happened. This season he went the full ten days.
“Last year we pulled forward a touch, about the 28th or something like the 27th. And then now, yeah, did the full.”
Mating moved with it, starting about a week earlier. The mating period itself is unchanged at ten weeks. He is starting earlier and finishing earlier, not stretching it out.
“Mating length is still only 10 weeks. We’re starting early and finishing early.”
He is not treating it as settled either.
“See how that goes. We might have to drop it back a bit more.”
What has changed is that he now has the information to make the call. A full season in the barn told him where the trigger points are.
“Knowing what you know last season, you know the trigger points. You could say, oh, use this a bit more.”
The Calving Dates
Original planned start of calving: 1 August
Last season: Around 27 to 28 July
This season: 20 July
Total move: Ten days earlier than the original date
Mating start: About a week earlier than previous seasons
Mating length: Ten weeks, unchanged
Status: Under review. Willie will adjust again if the season tells him to
What Ten Days Is Actually Worth
We are not going to put a dollar figure on this, because Willie did not. What he did say is that the barn is what made it possible, and that it was not on the list when he built it.
Ten days at the front of the season is ten more days of milk from every cow that calves in that window, in a year where the barn is also holding condition through the winter and letting him feed maize right through the wet. Those three things compound, and they are the reason he describes the whole season as different rather than pointing at any single gain.
Doubling The Round In Autumn
In late March, Willie went from a 30 day round to a 65 day round. It happened inside a fortnight.
“I literally doubled my round speed on farm. It was probably about end of March and we went from the 30 day round to 32 day round to 65 day round, just like that.”
The mechanism is simple enough. Milkers went in the barn every night for the last six weeks of milking. Days in the paddock, nights inside on the compost bed, out in the morning to be milked, then back out to grass.
“In the autumn, every night they were in here. During the day they’re in the paddock and that night they’re in here.”
Take a herd off pasture for twelve hours a day and the round stretches. The grass gets more than double the recovery it was getting.
The Reason He Actually Liked It
People asked him why. His answer had nothing to do with the round.
That is a man describing six weeks of not walking a paddock in the dark before milking. The pasture result was real, and it was not what sold him on it.
The routine underneath was about as simple as it gets. Grass through the day, supplement in the barn after milking, and that was it.
“Feeding them a load of grass silage and maize, that was it. They got their supplement after milking or evening, and their grass during the day. Pretty simple, the way it is.”
The Autumn Round
Period: Last six weeks of milking, from around end of March
System: Herd housing. Paddock by day, barn overnight
Round before: 30 days
Round after: 65 days
Time to make the shift: Roughly a fortnight, via 32 days
Feed in the barn: Grass silage and maize, fed after milking
Feed by day: Grass
Labour change: No morning walk to bring cows in
Flexibility Instead Of Pressure
The other thing that went away was the early start under pressure. At the runoff, a rough night means getting up there in the dark, because you want to shift them before it gets light and they start milling around.
“You get out and you’re up there when it’s still dark. You want to shift them before it’s light, before they start milling around.”
In the barn, that decision waits for him.
“Here you don’t have to worry with that. It might be half nine and you think, oh yeah, we’ll put these on the grass. Or, no, it’s a bit wet today, we’ll just leave them in here.”
“You don’t have those real pressures as such. You’ve got that flexibility.”
A 65 day round is the number that goes in the case study. The half nine decision is the one Willie talks about.
Cow Comfort And Health
The clearest sign the barn was working came from the cows, not the numbers.
Asked whether he comes in and finds cows lying down, Willie did not hesitate.
“Oh yeah, definitely. You come here in the morning, we put milkers in here overnight, rubbish evenings and that, you go get them and put them in here.”
Cows that are uncomfortable stand. Cows that are lying down have made a decision about where they are.
They Will Not Come Out
The stronger evidence is what happens when he opens the gate on a bad day.
“If it’s a cold, blowing southerly, you just feed out in here and they won’t want to come out. You can open the gate and they’ll turn around.”
There is a better story than that one. A southerly came through during milking, and Willie let the first two rows go back out. The third row broke the wire, snapped the tape, and came straight into the barn.
“By the end of milking, those two rows, they turned around and came. They got the idea too. They all came in good. It was cold and rubbish outside and raining.”
The cows that had been sent out worked out where the other lot had gone and followed them in. Nobody drove them.
Willie’s read on it is characteristically unsentimental.
“You might create a bit of a soft cow, because as soon as it rains they sort of look for a place to come.”
Then, immediately after.
Mastitis
This is the question every farmer asks about a compost bed, and Willie’s answer is that nothing changed.
“No. It’s not like we said, oh, it’s higher than other years or whatever. That’s all just the same.”
No increase on previous seasons. Not better, not worse, the same.
His explanation is the composting itself.
“If it’s composting well, you shouldn’t have bad bacteria in that. It should be heating up and it’s killing that. That’s the idea with it.”
That is the theory in plain terms, and his bed has run at around 55 degrees. The practical version is that a bed which is cooking is doing hygiene work, and a bed which has stopped is not. It puts the ripping routine in Managing The Compost Bed in a different light. The aeration is not just about keeping the surface soft.
Weather Getting In
A southerly blows into one side, and the curtains stop most of it.
“It sort of comes in that side, probably about a cow width or something. It’s not like it’s getting sopping. It’s not wet or anything.”
Rip through it and there is dry product on top again. A cow width of weather down one side, on a bed close to a metre deep, is not a problem he has had to manage.
What The Neighbours Call It
The barn has a name locally, and Willie did not give it one.
“They call it the Hilton. This neighbour up the road, just like, oh, your cows look good in the Hilton tonight.”
He takes the point.
“Well, it probably is like that compared to being outside under a tree.”
The neighbours who say it are at the other end of their careers and farm a different way. Willie is straight about that too, and about what they actually think of it.
“They would all love it. Definitely jealous.”
Airflow: The Question Everyone Asks
This is the objection that comes up more than any other, and Willie hears it constantly.
People look at a mono-pitch roof with a lower profile than a big gable barn and they assume it cannot breathe. Willie was asked it straight, and his answer was equally straight.
“I’ve never had a problem with airflow through here.”
How The Air Moves
There is a gap at the top, and you can stand in the barn and feel it.
“We’ve got a gap at the top and, because you actually stand here, you can actually feel it coming through.”
That is not a measurement, and Willie does not claim it is. It is a farmer standing in his own barn on a winter morning, feeling air move past him. He describes it as pumping through.
The site helps. They are in an extreme wind zone and they get strong winds coming through. The barn was designed for that in the first place, which is why the structural spec is what it is.
“We get pretty strong winds come through here. The airflow’s all right, don’t worry about that.”
The Curtains Breathe
A fair question is whether the curtains choke it. They do not, because they are not solid.
“It’s sort of like a canvassing material. You sort of think you could go through it. It’s not like if it was plastic, that can’t breathe at all.”
Mesh curtain rather than solid sheet. It stops the weather driving in without sealing the barn up. That is the trade a solid curtain cannot make.
The Proof Is In The Bed
Willie is upfront that he does not know the science, and then he points at the thing that settles it.
“I know there’s some barns that talk about needing a certain angle of roof and needing airflow. I don’t understand the science behind it, but you can actually feel it coming through. But I mean, ours has composted ever since.”
That is the argument. A compost bed only cooks if it is getting air. A bed that has run at around 55 degrees for a full season, that steams up across the whole barn every time it is ripped, and that fired back up inside a week after two and a half months idle, is a bed that is breathing.
“You rip this and the thing will steam up like anything. You dug a hole and saw how warm it is in there.”
If the airflow was wrong, the compost would have told him a year ago.
What This Does Not Tell You
Worth being clear about the limits of one barn on one site.
This is a mono-pitch barn with a 5 degree roof, mesh curtains, a gap at the top, in an exposed high wind location in the Wairarapa. It has composted continuously for a full season under that combination. It does not follow that any mono-pitch barn on any site will do the same.
Roof angle, ridge opening, curtain material, prevailing wind and shelter around the site all change the answer. That is the part worth working through properly before a design gets locked in, rather than assuming a spec that worked in Carterton will work in a sheltered gully somewhere else.
How The Structure Has Held Up
A year in, through a full season and a Wairarapa winter, Willie’s summary is short.
That is the headline, and it is worth having in plain terms because a barn is a twenty year decision, not a one season one. What follows is the detail, including the one thing that did need sorting.
The Curtains
The curtains were the part they watched most closely, and they were the part that needed a fix.
“We were always a bit worried about the curtains. We haven’t had any issues with that now that we’ve screwed them down properly.”
The problem was fixing, not material. Getting the right screws to hold took some trial and error early on.
“It was just a teasing thing, just trying to get the right screws to hold.”
The fix was to screw right through into the bars rather than into the boards alone.
“Now we’ve actually screwed right through to through the bars as well. So they’re solid on there.”
Since that was sorted, no further problems. For anyone specifying a barn in an exposed site, that is the detail worth carrying forward. The curtain material has done its job. The fixing method is what wanted attention.
Height And Access
The tractor fits, and it fits comfortably.
“We fit in here nicely with the tractor.”
He has not had a truck all the way in during normal operation, other than at the start. When the sawdust trucks come in for a top-up, they come right in and drop at each end rather than backing in.
“He was fine in here.”
The Structure At A Year
Overall condition: No issues reported
Curtains: Sound. Fixing method revised early, screwed through to the bars
Weather ingress: About a cow width down one side in a southerly. Bed stays dry
Wind exposure: Extreme wind zone site. Strong winds regularly through
Tractor clearance: Adequate. No issues working inside
Truck access: Trucks drive in for bedding top-ups
Bedding Wear At The Feed Face
The one part of the barn that is genuinely wearing is not the structure. It is the bed at the feed face.
That is covered in Bedding Top-Ups, and it is also the reason for the trial Willie is about to run. That comes next.
Labour and Time
Willie has no staff. He does the lot himself, including the ripping.
That is worth stating before any of the numbers below, because a labour figure only means something once you know who is doing the work. Everything in this section is one man, on a 250 cow farm, running a barn on his own.
The Honest Answer On Time Off Farm
Milan asked him directly whether the barn had given him more time with family, the intangible stuff that does not show up in a budget. Willie did not take the easy answer.
“I don’t know if it does. During the day you’re still having to be here and feed the stock. I don’t have staff or anything, so I do it all, and rip and that.”
A barn does not reduce the hours. It changes what the hours are spent on, and when.
The gains he does claim are specific and they are about timing rather than total workload. No walking a paddock in the dark before milking. No shifting a mob at first light because a wet night has turned rough. A decision at half nine in the morning about whether they go out at all. That is not less work. It is work that happens when he chooses.
The Daily Job
Ripping the bed takes about ten minutes, every second day.
“Ten minutes. It doesn’t take long. Ripping doesn’t take long.”
Two passes, shallow then deep, as set out in Managing The Compost Bed.
Tractor wear has not been an issue.
“It’s not like ripping out in the fields. Once you’ve gone through the first time and your second time, easy as.”
What he is firm about is the tractor itself. Four wheel drive is not optional.
“I thought you could get away with just a small two wheel drive tractor, but you wouldn’t. Especially once you’ve got a full bed. You need four wheel drive.”
He is quick to add that this is not much of a barrier these days, because most farms have one.
Getting Away
This is where the labour picture changes most.
Willie is going away for ten days next month. The cover plan is one bloke who can drive a tractor, shown how to rip the bed a few times.
“I’ve got a good guy. He knows what he’s doing, he’s driven tractors before. I’ll show him how to rip it a few times and he’ll be fine.”
Before the barn, going away meant a different arrangement entirely. Stock went to the support block, and there was nothing on farm to manage.
“They’d be off at the support block. You wouldn’t have anything on farm.”
That is not nothing. Sending 55 animals up the road is a real cost and a real logistics job, and the barn takes it off the list.
Where The Barn Sits
Position has turned out to matter as much as anything for labour, and Willie would build it in the same spot again.
The barn is close to the cowshed, with a cow lane beside the road. The clearest test of that came when a relief milker was on.
“She just came in and there was no, she didn’t even need the quad. Just walk down here, push the cows out, and they just walked into the cowshed.”
A relief milker who does not need a quad, and does not need to know the farm, is a barn positioned properly. Close to the shed is the whole of the advice.
“It’s in a good position. Anywhere close to the shed is good. Straight in.”
Labour At A Glance
Staff: None. Owner operated
Ripping time: About ten minutes
Ripping frequency: Every second day this winter, twice a week previously
Runs to cover the barn: Four
Tractor required: Four wheel drive
Tractor wear: None reported
Holiday cover: One competent tractor driver, trained on the ripper
Previous holiday arrangement: Stock shifted to the support block
Morning muster: Not required. Cows are already in
Relief milker requirement: No quad needed
Sawdust Supply: The Real Constraint
Ask Willie what he tells farmers who ring him about the barn, and the first thing he wants to know is where they farm.
“Probably the big one is, the first question is whether they’re in the Wairarapa or not. Because if they’re in the Wairarapa, we’ll be all fighting for the same product, so tell them no.”
He is joking. He is also not joking, and that is the most useful thing in this section.
“If they’re anywhere outside the Wairarapa, go for it.”
A local farmer is coming down to see the barn this month, and Willie’s line about him was the same.
“He’s from the Wairarapa, so I can’t tell him how good it is.”
Why Willie Has It Easy
Carterton sits near a couple of mills, and that is the single biggest reason his running costs work the way they do.
“We’re pretty fortunate here. We’ve got a couple of mills here, so we do get sawdust quite easily.”
Around 200 cubic metres a season, four truck loads at a time, delivered into the barn. That is a straightforward transaction where he farms. It is not straightforward everywhere.
Where It Gets Hard
Willie has talked to farmers in the South Island, the Waikato and around Taupō, and supply is their biggest problem. Not the barn. The bedding.
“That’s their biggest struggle, trying to find product, trying to actually get it. And then when they get it, they’re paying a lot for it.”
Two separate problems sitting on top of each other. Availability first, then price once you find it. A barn that works beautifully on paper stops working if the sawdust is four hours away and priced accordingly.
This is the question to answer before a barn gets designed, not after. Where the bedding comes from, what it costs delivered, and whether that supply is still there in five years is a bigger call than roof pitch.
Growing Your Own
There is a way around it, and Willie heard it from a farmer in Taupō back when he was still looking at barns.
“He was talking about planting part of a pine forest. He worked out that he needed whatever, a hectare a year of pines, and he will chip those up and that’s what he’ll use for his product.”
Plant a block, let it get to eight or ten years, mill or mulch it, and use it as bedding. Replant the same area each year and the supply renews itself on a rolling cycle.
Willie has done the sums for his own place and thinks the area needed is small.
“Something like this, you probably wouldn’t have to use much. Half a hectare of ten year old pines or something, put them through a mulcher and you’ve got your product. You’re all self-sufficient really.”
“Every year you harvest half a hectare and you plant another half hectare.”
He has not done it. It is an idea he rates rather than a system he runs. But for a farmer in a region where sawdust is scarce and expensive, a hillside that is not doing much else is worth a look before ruling a barn out.
Supply At A Glance
Annual requirement, Willie’s barn: Around 200 cubic metres of sawdust
Delivery: Four truck and trailer loads per top-up, twice a season
Local supply: Two mills nearby, readily available
Reported difficulty elsewhere: South Island, Waikato, Taupō. Availability and price
Alternative approach: Rolling pine block, harvested and replanted annually
Estimated area for a barn this size: Around half a hectare of ten year old pines per year, Willie’s estimate
Status of alternative: Discussed, not trialled
The Point Underneath It
A composting barn is a bedding system with a roof over it. The structure is the part that gets quoted, photographed and argued about, and it is the part that is easiest to get right.
The bedding is the part that decides whether it works for twenty years. Willie’s barn composts because he can get sawdust, cheaply, from up the road, twice a season, without thinking about it.
That is worth knowing before anyone puts a peg in the ground.
The One Thing He Would Fix
Nothing about the structure is on Willie’s list. The bed at the feed face is.
It is the only recurring maintenance job the barn creates, and it is the reason for the two bedding top-ups a season set out in Bedding Top-Ups. The cows stand in the same place while they eat, and the bed chews out under them.
“The cow literally walks up and that’s where they’re always standing. When they’re eating, they’re always standing in that spot.”
Top it up and it comes back. A few days of cows on it and it settles again. Solid, but lower. Get down far enough and the heifers start having to reach for their feed, which is where it stops being cosmetic.
He has already tried the free fix. Pulling sawdust across from the middle with a grader blade dished the bed out and the next rip undid it. So the question became whether there is a permanent edge that stops it happening at all.
Why He Ruled Out Concrete
The obvious answer is a concrete lip along the feed face. Willie talked himself out of it in about thirty seconds.
“You’d have to dig that all out. It’d be quite an effort, actually dig it all out and box it up. You’d have to build it up. It’s 800 down.”
The bed is close to a metre deep. Putting a concrete edge in means excavating to a firm base, boxing, pouring and building back up, in a barn that is in use.
Then there is the part that worries him more.
“You don’t want to just go ahead and do a concrete lip and then find that you just move the problem over here.”
A hard edge does not stop a cow standing in the same spot. It moves the wear to the other side of the edge. He is not confident enough that it solves it to justify the excavation.
“I wouldn’t go down that line. I’d just carry on with the sawdust.”
The Rubber Trial
Willie raised rubber himself. Milan and Jacob had been talking about the same thing the day before.
The idea is heavy duty track rubber, the conveyor belting type. Cut to length, laid along the feed face, held down so the cows cannot lift it.
The fixing is the part that has to be right. The rubber cannot pull away from the wall or a cow will get a foot under it.
“Probably just the biggest thing is, is it fixed so they don’t come away from the wall.”
The method discussed on the day was an L bracket, screwed through the board and into the poles, with the rubber then bolted underneath so it cannot be pulled.
“Screw it straight to the board, into the poles, and then just bolt it underneath. Screw it into the rubber so it can’t pull it.”
Width is still being worked out. Going out as far as the pole is about a foot. Willie’s instinct is that it does not need to be that far.
“I’d go for 300 to start with. It might come back and I might say, oh yeah, no, actually a bit more.”
The ground goes in first. Dig out to firm, so the rubber is not sitting over something that will dish out underneath it.
Why He Is Willing To Try It
The appeal is that it is reversible, and concrete is not.
“If it doesn’t work anyway, it’s unscrew it. I haven’t got much to lose there.”
That is the honest reason this trial is happening and a concrete lip is not. One of them is a decision. The other is an experiment.
The Trial At A Glance
Problem: Bed wears down at the feed face where cows stand to eat
Current management: Two sawdust top-ups a season, roughly 200 cubic metres
Option ruled out: Concrete lip. Excavation to 800mm, and risk of moving the wear rather than stopping it
Option being trialled: Heavy duty track rubber along the feed face
Proposed fixing: L bracket screwed through the board into the poles, rubber bolted underneath
Proposed width: 300mm to start, adjustable
Preparation: Dig out to a firm base first
Status: Not yet fitted. No results
Reversibility: Unbolts and comes out if it does not work
No Result Yet
This is a trial, not a solution, and we are not going to write it up as one.
Nothing has been fitted. Nothing has been tested. The idea came out of a conversation in the barn, it is going in on that basis, and if it does not work Willie will take it out and carry on with sawdust.
We will publish what happens either way.
Extending The Barn
One of the first things farmers noticed at the discussion group was that the barn could be made longer without much of a fight.
They were right, and Willie confirms it.
“Very easy. Literally just carry your purlins off the back.”
There is no finished end to demolish. The barn does not terminate in anything that has to come apart before it can grow.
“There’s no finished end on it or anything. It’s literally just whack some more poles up and keep going.”
No Concrete To Break Out
This is the detail that makes it cheap, and it comes down to the design.
“You don’t have to break up any concrete. No concrete, nothing.”
The compost bed runs on ground, not slab. Extending the barn means extending a bed, not cutting and removing an existing floor. Poles, purlins, roof, curtains, and more bedding into the new section.
That is a different proposition to extending most farm buildings, and it is worth understanding before a barn gets sized. A barn that is too small can be made bigger later without penalty. A barn built too big is capital sitting idle from day one.
What Another 50 Metres Would Do
Willie has a number in his head for it.
“If we want another 50 metres on it, chuck another, go up to 300 or 320 cows or something.”
The barn is currently 82.8 metres long and sized for 250 cows. Another 50 metres would take it to around 320.
He is not planning it. He is describing how easily it could be done, which is the point.
He Is Not Even At Capacity Yet
Before extending comes anything, there is room in what he has already built.
Willie is only feeding one side of the barn this winter, because of the baleage binding up the ripper. Feed both faces and the same structure carries a lot more.
“We’re only feeding on one side. We could feed on both sides. That’s 100 and something cows.”
“Who knows, next year we might do more.”
The way around the baleage problem is a different feed. Maize or fine chop silage does not bind the ripper the way baleage does, which he already knows from the previous season.
So the growth path runs in order. Fix the feed type, use both sides, and only then look at more poles.
Extending At A Glance
Current length: 82.8 metres
Current capacity: 250 cows
Currently feeding: One side only, this winter
Untapped capacity in the existing barn: Both feed faces in use
Method of extension: Carry the purlins, add poles, extend the bed
Concrete to remove: None
Finished end to demolish: None
Willie’s estimate for 50 more metres: Around 300 to 320 cows
Why Farmers Pick This Up Quickly
Willie says it is the thing people see straight away when they walk in.
A design that can be extended with poles and purlins is a design that does not punish you for guessing wrong at the start. That matters on a farm where cow numbers move with consents, land, and what the season allows.
What He Tells People Who Ring Him
Willie gets phone calls. He has done since the open day video went up, and they have not stopped.
“I’ve had a few people ring about it. A few people ring up, they’re interested about it and just talk to me.”
Some come from the video. Some come from field days, where blokes who did not go still ended up hearing about it. One came from the builder who put the barn up.
“Even my builder that built it, he said the same. Oh, good video.”
A local farmer missed the discussion group day, saw the video, and is coming down to see it running rather than parked up for an open day.
Willie’s attitude to all of it is straightforward.
“Everyone’s always asking so many questions. That’s just trying to pass on the learnings to everyone else.”
Asked Directly, The Answer Is Yes
Milan asked him what he says to someone thinking about building one. There was no hesitation in it.
“Look, I would do it anytime. I’d build another one of these. No worries.”
Then the joke he has clearly used before, and the qualifier underneath it about where the sawdust comes from.
“The first question is whether they’re in the Wairarapa or not, because we’ll be all fighting for the same product. Anywhere outside the Wairarapa, go for it.”
What Sally Says
Sally is the one looking at the financial end of it, and Willie’s read on where she has landed is short.
Then the line that says more than a spreadsheet would.
“She’s probably thankful, why didn’t we do this years ago.”
A Tool On The System
The most considered thing Willie said all interview came when he was talking about someone starting out.
“If you’re starting your career, or like, we’re only, this is our sixth season now in this place. It’s something like, we’re going to get years out of this. It’s a tool on the system.”
That framing is worth holding onto, because it is the opposite of how a barn usually gets sold. Not a fix for a wet winter. Not a shed. A tool that changes what the rest of the system is capable of.
Everything else in this post is downstream of that. Calving ten days earlier. A 65 day round in the autumn. Maize fed right through the wet. Cows dried off in condition without a scramble. Five or six hectares of winter grass instead of a paddock full of mud.
None of those were the reason the barn went up. All of them happened because it did.
“That’s another gain that you don’t really think about when you put up a barn like this.”
Thank You, Willie, Sally And The Bosch Family
Willie has now opened his gate to us twice.
The first time was the open day, with over sixty farmers walking through his barn and asking him everything they could think of. This time it was a normal winter morning, no crowd, just Willie standing in the barn answering questions for the best part of an hour while there was plenty else he could have been doing.
He answered all of it. The bits that worked and the bits that did not. The grader blade experiment that came to nothing, the curtain screws that took a few goes to get right, the honest answer that a barn has not given him more time off farm. Plenty of farmers would have left those out.
That willingness to be straight about the whole picture is what makes any of this useful to the next person deciding whether to build. A case study that only carries the wins is not worth reading. This one is, and that is down to Willie.
Thanks also to Sally and the family, who have carried the other end of this. Willie was quick to point out that Sally is the one looking at the financial results, and that she is the one wondering why they did not do it sooner.
Willie has spent a year fielding phone calls from farmers he has never met, and his reason for it was simply that everyone is always asking, so he is passing on the learnings. That is a service to the industry, and it is not one anybody is paying him for.
From all of us at Numat, thank you.
Why This Barn Was Built This Way
Willie did not come to us wanting a composting barn. He came wanting to run more cows on flat land with a maxed out effluent area, and to feed them properly through a wet Wairarapa spring.
The barn is what came out of working through that. Mono-pitch roof at 5 degrees because a gable would have cost more without doing more on that site. Feed faces on both sides with the compost in the middle, because he wanted a barn that worked as a feed pad in summer and a winter barn in July. Mesh curtains and a structural spec built for an extreme wind zone, because that is where the farm sits.
None of those were catalogue choices. They came from the site, the herd, the effluent position and what Willie wanted the farm to be doing in ten years.
That is the part worth saying plainly. A composting barn is not a product you pick a size of. The bedding supply in your district, the feed you can actually grow or buy, your roof angle against your prevailing wind, and whether you need it working twelve months a year or three, all change what you should build. Get those wrong and you have a very expensive shed.
We would rather work through that properly with you and tell you a barn is the wrong call than sell you one. Willie’s barn works because the thinking happened before the pegs went in.
Numat Construction designs and builds composting barns, feed pads, loafing pads and free stall barns across New Zealand. Every one of them starts with the same conversation Willie had, which is what the farm actually needs, before anything gets drawn.
Compare off-paddock systems
This guide lays out all eight side by side: the m² per cow, the build cost, the cleaning demands, and the farms already running them.
Let’s Price It Right
Get real numbers, not guesses.
We’ll show you the smartest way to build your composting barn: cost-efficient, practical, and built around your farm.
Related articles
-
6 July 2026Read more
Wintering Under Cover in Canterbury – By Keith Woodford
The Wintering in Canterbury: Infrastructure & Forage Crops conference ran on Wednesday, 1 July 2026, in Ashburton. Farmers, sharemilkers, and
-
2 July 2026Read more
Composting Barns By The Numbers: My Takeaways From Ashburton
Compost temperature, moisture ceilings, bedding ratios, and why gable roofs win over hoop barns long term. Jacob shares his notes from a…
-
18 June 2026Read more
250-Cow Timber Composting Barn Underway in Southland
Glenfruin Farm is putting up a 24m x 94m composting barn in Southland to winter 250 cows off the wet paddocks. Centre…
