Sheep shed

I used to lamb the ewes out but because the father is no longer fit to catch one in the field if i'm away i now house them. We build a general purpose shed about four years ago and it suits my purpose very well and its by no means fancy. Its a five bay loose house each bay is 16ft and its 35 ft wide. Block walls along both sides and fully open at one end and a block wall and feeding gate at the other end. I sourced large 25ft uprights out of a power station which have a 2ft sq base plate and welded a steel beam to the tops of them to span the 35 ft. The tin for the roof was sourced from a neighbour who was dismantling a poultry house and i had the chance to take all the timbers and tin for dismantling the shed for him, the tin is a bit on the light side but sheets were 25ft long and i still have dozens of them left after doing the roof.
The floor is a gravel soakaway and is bedded with woodchip, i get a ro-ro skip of it before lambing and bed the floor about twelve to fifteen inches with it and only ever have to add chip to where the sheep are feeding around the silage feeders. Its great stuff and really cuts down on lameness compared to when i was bedding in straw and the sheep keep pawing at it when they go to lie down so naturally keep turning it over themselves. the key to it is to make sure the chip is the right size, i use 2 inch chip which is waste timber rather than natural timber as it has more soakability. The urine and dung just gets soaked up and turned over and we also use it for bedding the bulls and does a grand job with them too.
The block walls along the sides are seven ft hight with yorkshire cladding spanning the remaining 6ft to the roof, it allows plenty of ventilation and the open front ensures that theres plenty of air. Two bays are used to house the triplets from 1st January and fed a round bale throught the feeding gate and troughs along the wall for when i start feeding them meal. The other three bays are then used for housing the twins about 1 week before lambing. I have a lean to which i have thirty pens in for putting all lambed ewes in, this is on a concrete floor and everything is limed and straw bedded before a ewe goes into lamb, just makes it easier to clean out and wash down every day. I have hayracks that User John has and find these great for keeping silage off the ground. The whole house will accommodate about 125 mule ewes at any time and i do find it a great help but there are downsides.
Pros - problem/dull sheep are noticed quicker as i'm always passing the house
4am lambings or problem lambings as easily caught, if you think a ewe might be going to give problems throw her into a pen and come back and look her in an hour, rather than search for her in a field with a torch
Sheep are less likely to take twin lamb disease as they're less stressed by wet weather and bullying at the feeders/troughs
Allows me to condition score ewes better and house triplets after scanning
The father can take a shift every so often and give me a shout if he needs a hand
Re-house young lambs if the weather turns bad

cons - more labour intensive - i find i do nothing else when lambing except hang around the shed
individual lambing pens MUST be cleaned after each lambing and i still have cases of joint ill

In fairness we probably built the shed for probably less than £3K and the ewes are only in it for a period of a month with the triplets in for 10 weeks, two of my neighbours built sheds two years ago and each spent between £35-£40K on their respective sheds. They are cracking sheds but have severe design flaws in their flooring system as one uses mesh and the other uses straw. the mesh gets blocked with the baled silage - i believe if you put sheep on mesh they need to be fed precision chop silage, the straw bedded house ends up very damp as the sheep are in pens 20ft x 18ft and as the sheep eat along the middle passage they dirty the straw badly at the front and sheep go lame quickly. One of the houses has ventilated tin cladding but air circulation seems to be worse than mine and at the end of the day they can only ever be used for housing sheep whereas mine is a loose house and we have used it for many a thing. My advice is to be flexible with your design at first and see what works for you