Planning a fully off-grid cabin — where to start?

Right, so I'm looking to convert an old shepherd's hut on family land in the Cotswolds into a proper off-grid setup, and I've absolutely no idea where to start — which is probably evident from my username.

Currently it's got mains leccy and water, but the plan is to go fully independent because, let's be honest, the grid's become about as reliable as a chocolate teapot lately. The hut's maybe 20m² and will be used intermittently — weekends mostly, occasional week-long stays.

I've been lurking on here for months and keep seeing folks mention starting with loads calculations, but I'm not even sure what I'm actually using in terms of power. Got no heating sorted yet — was considering air source heat pump but that seems mad for a tiny hut. Probably just need a decent wood burner and some backup leccy for lighting, fridge, maybe a kettle.

The water situation's trickier because there's a small stream about 30m away, so I'm thinking rainwater harvesting plus mains backup for now, then potentially gravity feed from the stream once I understand how.

Should I be looking at batteries first or solar panels? The hut faces south-ish and gets decent light, but I've no clue if it's enough. Also, is it mental to hire someone to do this properly, or will I end up bankrupt? The budget's flexible-ish but not unlimited.

Any pointers on what I should actually measure/assess before throwing money at kit?

Shepherd's huts are brilliant for off-grid conversion — the setup largely depends on your usage patterns and budget. Before spending a penny, nail down:

Load assessment — what are you actually running? Heating, lighting, fridge, shower? A weekend retreat differs massively from full-time living.

Location specifics — how much winter sun hits that hut? Wind exposure? Soil type matters if you're thinking groundwater.

Budget ballpark — honestly, this shapes everything. A basic system (battery, panels, charge controller) can start around £3k-5k, but comforts add up quickly.

I'd sketch out your typical day: hours you're there, what appliances run simultaneously. Post that back and folks here can point you toward realistic kit — Victron, Fogstar, whatever suits your scale.

What's the primary use case? That'll help people give proper direction rather than guessing.

Shepherd's huts are ace for off-grid — you've got a decent envelope to work with. Before you spec anything, nail down your actual power requirements. Are you living there full-time or weekends? Running heating, cooking, hot water?

I'd start with an energy audit: list everything you want to run and how many hours daily. That determines your battery bank size and panel array — and honestly, that's where most people go wrong by oversizing everything.

For Cotswolds location, you're looking at roughly 3-4 peak sun hours in winter, so factor that in. A modest system might be 5-8kWp panels with a 10-15kWh LiFePO₄ battery (Victron or similar), depending on usage.

What's your rough annual budget? And are you thinking mains water/sewage alternatives too, or just power? The two often go hand-in-hand in planning.

Spent a summer living in a converted narrowboat, so I've got a soft spot for these quirky builds. The Cotswolds site is your biggest advantage — you'll likely get decent solar exposure if you've got south-facing roof space.

Before you touch anything, get a surveyor to check the hut's structural integrity and damp situation. Shepherd's huts weren't designed for permanent occupation, and moisture will absolutely wreck your electrics if you're not careful.

Once that's sorted, think about your actual daily loads — folk often overestimate what they'll use. A small Victron setup with 10-15kWh battery storage handles most off-grid cabins brilliantly, paired with decent solar. Winter's the killer though; Cotswolds aren't exactly sunny December-January.

What's your usage vision — weekends only, or full-time?

The key thing nobody's mentioned yet — and I learned this the hard way in my van — is shadow patterns. A Cotswolds site in winter is brutal for solar. Before you buy a single panel, spend a month mapping where the sun actually hits your hut throughout the year. You'll likely need more battery than you think.

For a shepherd's hut, I'd skip the grid-tie stuff and go full battery backup. Victron kit's pricey but it'll save you grief. Pair it with a decent LiFePO₄ bank — not lead-acid, trust me on that — and you're looking at 10-15kWh minimum if you want proper comfort.

Get your heating sorted first though. That'll be your biggest draw. Efficient wood burner or air-source heat pump if you've got the budget. Solar alone won't cut it for winter heating.

What's your current usage like? And have you got a digger access for groundworks?

Has anyone actually measured the solar potential on the site yet? That's what I'd do first before spending a quid on anything.

@MarinePhil's spot on about shadows — I've got a garden office and spent three months tracking the sun's path before finalising panel placement. Worth doing a proper site survey, especially in the Cotswolds where you've got hills and trees everywhere.

Key questions: which direction does the hut face? How much unshaded roof or ground space have you actually got? What's your winter sun angle like?

Once you've got that data, you can work backwards — how much battery storage you'll need, whether you're looking at a small wind turbine (though Cotswolds wind is patchy), and if you need a backup generator. Victron's planning tools are quite useful for modelling this.

The shadow thing will make or break your setup, honestly.

Shadow mapping is crucial — @HollyGazer's spot on there. I'd add that winter sun angle in the Cotswolds is brutal; you're looking at maybe 15° elevation in December. Get the PVsyst software running or at least use Google's Project Sunroof to see what you're actually working with.

That said, don't let imperfect solar paralyse you. My narrowboat's shaded half the day but I've still got a decent winter baseline with a 2kWp array and a Victron MPPT controller. A shepherd's hut gives you more roof area than a boat, so you've got flexibility.

Next: establish your actual loads. Heating? Hot water? That's where most people get caught out. A cabin with proper insulation might need way less than you'd expect, but a draughty hut is a battery killer.

What's your current infrastructure like — any mains access for backup?

Jumping in as someone with a static caravan setup — before you commit to solar positioning, have you thought about what your actual load profile will be? That shapes everything else.

I'd map out:

• Winter vs summer usage patterns (are you there year-round?)
• Essential vs nice-to-have loads (heating, lighting, fridge, etc.)
• Whether you're grid-connected nearby as backup

The reason I ask is the Cotswolds winter situation @HeathGazer mentions is real — you might find a hybrid approach works better than pure solar. Battery capacity becomes your actual constraint, not panel count.

For a shepherd's hut specifically, have you checked the roof loading? Some of those older builds won't take much weight. Might influence whether you're looking at ground-mount panels instead, which actually solves the shadow issue @MarinePhil raised quite neatly.

What's your rough timeline for this?

Spot on about the shadow mapping — I'd say that's non-negotiable. But before you even think about panel angles, nail down your actual energy needs. Shepherd's huts are typically tiny, which is brilliant for off-grid, but I've seen folk massively overspec their kit because they haven't properly audited what they're actually running.

Draw up a spreadsheet: lighting, heating (this is the killer in winter), water heating, fridge if you're having one, phone charging, tools. Be honest about usage patterns. Winter in the Cotswolds means your solar generation will be mediocre at best, so you're probably looking at substantial battery storage.

I'd start with a modest system — maybe a 5-10kWh battery (Victron or Fogstar are solid), panels sized for your actual needs, and a backup (generator or grid connection during setup). You can always expand. Trying to go too ambitious from day one is expensive and frustrating.

Once you've got that audit done and the shadow mapping sorted, the rest follows. What's your heating plan, by the way? That'll dictate everything else.

The shadow mapping advice from @HeathGazer and @ExPostie is spot on — I can't stress that enough for Cotswolds installations. Winter solstice sun angle is roughly 15° elevation, so even small trees or building eaves can wipe out 40-50% of your generation Dec-Jan.

What I'd add: once you've sorted your panel orientation (south-facing, ideally 40-45° tilt for year-round performance), size your battery bank first, not after. That's where most people get it wrong. A shepherd's hut with minimal thermal mass will have erratic demand — you need to know your worst-case autonomy requirement before speccing panels.

For your setup, I'd suggest starting with a Victron Multiplus and matching MPPT controller. You can scale the array later, but the inverter/charger backbone needs to be right from the start. LiFePO₄ batteries (Fogstar or Renogy) are pricey upfront but will outlast lead-acid by a decade in a variable-use scenario like a hut.

What's your realistic occupancy

Right, before you disappear down the rabbit hole of solar specs and inverter sizing, ask yourself the harder question first: what's your actual consumption going to be?

I've seen too many people retrofit solar systems that are either wildly oversized (expensive, unnecessary) or undersized (frustrating in winter). You need to be ruthless about this.

For a shepherd's hut conversion, are you talking:

• Lighting, heating, water pumping only?
• Added EV charging (I assume that's not day-one priority)?
• Full-time living or seasonal use?

The Cotswolds winter is brutal for solar — you're looking at genuinely poor December/January generation. @LisaStewart71 and the others are absolutely right about shadow mapping, but that's only useful once you know what you're trying to generate.

My recommendation: Document a week of actual usage first if you can, then work backwards. Battery bank sizing will drive about 70% of your total cost, so getting that right matters more than having the "perfect" panel angle.

What's your rough timeline for this, and are you living there year

Mate, everyone's talking shadow mapping (and they're right), but honestly the real question is whether you're prepared for the psychological side of off-grid living in a shepherd's hut. You'll be living like a shepherd, minus the sheep keeping you company.

That said — and this matters — don't cheap out on your battery bank. I made that mistake.

The shadow mapping point is absolutely critical for the Cotswolds — you're looking at potential winter losses of 40-50% if there's any tree cover or terrain obstruction. Use PVGIS or even just Google Earth's 3D view to assess seasonal sun paths properly before committing to panel placement.

What I'd add that hasn't been mentioned yet: start with consumption profiling, not generation capacity. Work out your actual winter demand in kWh/day — not what you think you'll need, but what you'll actually use when there's no mains backup. A shepherd's hut with decent insulation and efficient appliances behaves very differently from a typical cottage. That number drives everything else: battery bank size, inverter rating, whether you need a backup generator.

Also, budget for a proper site survey. The difference between installing on south-facing roof versus ground-mounted on an unshaded patch could be several thousand quid over the system's lifetime. Victron's documentation on system design is genuinely helpful if you want to self-spec rather than hiring a surveyor outright.

What's your current water and heating situation? That

Shepherd's hut's a cracking project — just don't fall into the "bigger battery = better" trap like I did with the narrowboat.

Winter in the Cotswolds will humble you faster than a Victron monitor, so @VanGill's spot on about shadows. But here's what nobody mentions: a shepherd's hut's probably got zero insulation, so you'll be heating like you're powering a small country before you've even sorted the electrics.

Honestly? Get an energy audit done first (thermal imaging if you can swing it). Then work backwards from your actual winter demand — not summer fantasy figures. I'd estimate you're looking at 5-8kWh/day minimum once you've got heating sorted, which means either a decent battery bank or acceptance that you'll be grid-tied come November.

LiFePO4's worth the premium for a fixed installation where you're not weight-conscious like van or boat folk. And get your roof surveyed before committing to panel placement — old huts are stubborn about structural changes.

What's your rough timeline, and are you looking full off-grid or willing to keep

Shepherd's hut's a brilliant canvas for this. Few practical things:

Winter reality check — @VanGill's right about shadow mapping, but in the Cotswolds you're also dealing with shorter days full stop. Don't undersize your winter capacity expecting summer to bail you out.

Load profile first — figure out what you actually need before touching panels or batteries. Heating? Cooking method? Are you there year-round or seasonally? This changes everything.

Space constraints — huts are tight. You might be looking at a modest 2-4kW system max depending on roof orientation. Roof-mounted panels are usually your only option, which ties back to the shadow issue.

Consider hybrid — many hut setups work better with a small diesel backup or grid connection for winter months rather than oversizing battery bank. Sounds like defeat but it's genuinely more practical than maintaining 10kWh of lead-acid in a shed.

Start with a proper site survey (sun path, obstacles, building orientation). Once you know what you're working with, the actual kit choice becomes straightforward. Happy to discuss specifics