Garden offices have moved from a lockdown workaround to a permanent fixture of the Norfolk housing market. The electrical work behind one is not a socket in a shed. It is a correctly specified sub-main from the house, a properly sized consumer unit in the cabin, sockets and lighting laid out for how you actually work, data cabling pulled in before the walls close up, and in most cases air conditioning for year-round comfort. Hethersett Electrical installs all of this in a single project, across Norwich, Wymondham, Attleborough and the wider South Norfolk area.
Norfolk homeowners, fit-outs from first fix to sign-off
Garden room electrics
Garden gazebo install
Garden room with split air con
Garden workshop fit outA typical installation is five pieces of work, done in the right order. Skip any one of them and you end up with a cabin that feels like an extension lead with pretensions.
The supply comes first. A correctly sized sub-main runs from your existing consumer unit (or from a newly added spare way) out to the cabin, buried in SWA (steel wire armoured) cable at the required depth, protected against spade damage and damp. At the cabin end, a small dedicated consumer unit handles the circuits inside the office: one for sockets, one for lighting, and usually one for air conditioning.
Then the interior fit-out. Sockets are planned around how you actually use the space: one behind the monitor, one each side of the desk, one on the opposite wall for a kettle or a printer, one outside for a garden light or a garden mower charger. Lighting is laid out for task and mood, usually a mix of downlighters and a feature fitting, on a dimmer where it helps. Data and TV cabling is pulled in before the internal walls are lined, because doing it after costs three times as much.
Sign-off. You receive the Electrical Installation Certificate, a circuit schedule for the cabin's board and any air conditioning commissioning paperwork. We walk you through the controls and the maintenance points before we leave.
The thing that sets this work apart from a standard domestic job is the sub-main. Getting the cable size right for the run length and the likely loads (office equipment, air conditioning, a kettle, maybe a small electric heater) is the single most important decision in the whole installation. Undersized cable is the most common mistake on garden office electrics. Everything downstream of an undersized supply will feel underpowered, and retrofitting a larger cable once the garden is landscaped is expensive and disruptive. We size cable generously at the quote stage, not optimistically.
What we fit
We fit electrics for the full range of garden buildings, not just the prefabricated office pods.
The core of this service. Anything from a 3m by 3m pod from a manufacturer to a bespoke 6m by 4m insulated timber-framed room with a finished kitchenette corner.
Whether you have bought the shell from a supplier or are having a carpenter build one on site, we handle the sub-main, the cabin consumer unit, sockets, lighting, data, air conditioning and certification.
Existing summer houses are often wired off an extension lead or not at all. We can pull in a proper armoured supply, add a small consumer unit inside, and bring the electrics up to current standards so the building is usable year-round.
Hair, beauty, massage, yoga, photography and art studios in a garden room are an increasingly common use case. These need careful socket planning around mirrors, basins, equipment and task lighting, and often benefit from heat and cooling control beyond what a plug-in heater gives you.
Woodworking and hobby workshops usually need a heavier-duty supply for fixed tools (table saws, planers, dust extractors). We size the sub-main for the intended load and add dedicated 16A or 32A circuits where the equipment calls for them.
Older outbuildings often have ancient wiring running off a house radial. We can pull in a new supply, install a dedicated consumer unit and rewire internally to bring the whole building up to current regulations.
If your project is not on this list but falls under “building in the garden that needs proper electrics”, it is almost certainly something we cover. Call us and describe the building; we will tell you straight whether we are the right fit.
Power supply
The supply run is the spine of a garden office installation. Get it right and everything downstream works first time.
We almost always use SWA (steel wire armoured) cable for the outdoor run, buried to the correct depth, routed to avoid drains, gas lines and the inevitable future patio extension. In some layouts a surface-run cable on the house wall or along a fence line makes sense; we will specify which is right for your site at quote stage.
We always fit a small dedicated consumer unit inside. Splitting the cabin's circuits (sockets, lights, aircon) onto their own MCBs means a fault in one circuit will not take out the whole garden building, and it gives you a local isolator if you ever need to work on anything yourself.
A 20 metre run feeding a small office with a 2.5kW air conditioner is a different beast from a 40 metre run feeding a workshop with a table saw. We calculate voltage drop properly, size the cable to keep it within regulations, and quote the right size first time rather than the minimum that would just pass.
Scope of works
A typical interior fit-out from us includes the following. On workshops and studios the list is adjusted to the use; we will confirm the scope line by line in the written quote.
Heating & cooling
The single most common complaint we hear about garden offices is temperature. A split aircon unit solves both the summer and winter problem with one piece of kit.
South-facing cabins overheat from April through September. North-facing cabins are hard to heat in November and February. The “plug in an oil-filled radiator” workaround runs out of steam fast, and adding a portable air conditioner that needs a hose out of the window defeats the point of an insulated, finished building. A wall-mounted split air conditioning unit solves both problems with one piece of kit. Modern split systems heat and cool, run efficiently (even on cold days the heat output per kWh comfortably beats direct electric heating), and can be specified to match the cabin's volume, insulation and glazing.
<£2
Typical daily running cost in full use, 3m x 4m cabin
1 visit
Electrics and aircon commissioned together
Because Hethersett Electrical is both the electrician and the F-Gas certified air conditioning installer, both pieces of work happen in the same project. The air conditioning unit's circuit is specified and wired as part of the cabin's consumer unit; the refrigerant pipework and the condenser unit are planned into the external cable route from day one; and the whole system is commissioned and certified together. You do not have two trades arguing about whose job the last 200mm of cable is.
For buyers who would prefer not to fit air conditioning, panel heaters, electric underfloor heating and towel rail circuits are all straightforward alternatives. These are less efficient as heat sources and do not cool in summer, but the installation cost is lower.
See our air conditioning page for full details on what we fit and service.
Our process
Most projects are complete within two to five working days on site across the two visits, excluding any lead time for a new consumer unit or air conditioning equipment.
You call or fill in the quote form with a rough description of the project: size of cabin, whether it is already on site, approximate location in the garden, what you want it used for. Where helpful we visit to measure the cable run, check the existing consumer unit, and discuss socket and lighting layout. The visit is free.
You receive a written quote itemising sub-main, cabin consumer unit, sockets, lighting, data, air conditioning (if included), and certification. Where the work touches other services (consumer unit upgrade, EV charger, underfloor heating), those lines are separated so you can see the scope clearly.
If you approve the quote we book a date. For new garden rooms we coordinate with the supplier or builder so first-fix internal cabling can happen before the walls are lined, which usually means one visit during the build and a second for second-fix.
Sub-main trenching (or surface cable run), cable pulled and terminated at both ends, cabin consumer unit installed, internal cables dropped to socket and switch positions, data and TV cabling laid in. First fix is the messy stage; second fix is cleaner.
Sockets, switches, lighting, data faceplates, air conditioning unit indoor and outdoor, all installed and tested. The consumer unit is commissioned, every circuit is tested to BS 7671, and the certificates are prepared.
You receive the Electrical Installation Certificate, the full test results, a circuit schedule for the cabin's board and any air conditioning commissioning paperwork. We walk you through the controls and the maintenance points before we leave.
Cost guide
Every job is quoted individually, but the ranges below reflect what comparable projects in Norfolk have cost in 2026. All prices exclude VAT and assume the cabin itself is already on site or on order.
| Project | Typical range (ex VAT) | What it covers |
|---|---|---|
| Sub-main supply only | £650 | Up to 20m SWA run, cabin isolator, certification. No interior fit-out. |
| Small pod fit-out (up to 3m x 3m) | £1,150 | Sockets, lighting, cabin consumer unit, certification. No data or aircon. |
| Standard office (up to 5m x 4m) | £1,800 | Sockets, lighting, data cabling, cabin consumer unit, certification. |
| As above plus air conditioning | £3,800 | Add single split unit (heating and cooling), F-Gas certification, commissioning. |
| Workshop or studio | Quoted on survey | Heavier supply requirement, dedicated equipment circuits, three-phase where needed. |
| Consumer unit upgrade (add-on) | From £650 | If the existing house board cannot take the new circuit; added to any of the above. |
Note on pricing: Each project is priced individually on survey; these bands are a useful starting point, not a binding quote.
What pushes a quote up or down: the length and difficulty of the cable run (landscaped gardens with mature trees are harder than an open lawn), whether the existing consumer unit can take the new circuit or needs upgrading, whether air conditioning is included, whether data is run, and the finish level on sockets and switches (standard white moulded vs brushed steel or coloured). The single biggest number on our quotes is almost never the sockets or the lighting; it is the sub-main run and the cabin consumer unit. That is where the real work and the real cable cost sits. Anything downstream of that is comparatively quick.
Single-contractor delivery
The electrics and the air conditioning work better when they are planned, installed and certified together.
The usual alternative is to buy a garden room from a supplier (who offers “electrics” as an optional £1,500 add-on done by a subcontractor they rarely see), arrange air conditioning separately through an aircon installer who does not know the electrical layout, and hope the two jobs meet cleanly in the middle. They often do not. Using a single installer for the electrical fit-out and the air conditioning means one survey, one quote, one scope of work. You know what you are getting and who owns every line. The air conditioning circuit is specified before the cable is laid. The sub-main is sized to carry the load. The cable route in the cabin wall accommodates the refrigerant pipework. The outdoor unit position is agreed against the external cable route. For homeowners who have already bought a cabin with the supplier's electrics package, we can still add air conditioning and data as a separate project. Our preference is to be on site from first fix, but we work around what is already in place where we have to.
We subcontract regularly to Norfolk garden room suppliers and small builders, handling the electrical and air conditioning fit-out on cabins you have supplied. We work to your programme, handle F-Gas aircon in the same visit, and invoice you or the homeowner, whichever suits.
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FAQs
If your question is not covered here, call us on 07769 201050 or contact us via WhatsApp.
Usually, yes. A habitable garden room with electrics falls under the Building Regulations. We design, install, test and certify the electrical installation to BS 7671 (18th Edition) and issue an Electrical Installation Certificate on completion. The structural side (foundations, insulation, glazing) is normally handled by your garden room supplier or builder.
Most garden offices fall under permitted development and do not need planning permission, provided they are single storey, under 2.5m at the eaves, set well back from the highway and cover no more than half the garden. Listed buildings and conservation areas have extra rules. Planning is your responsibility (or your supplier's), but we will not install electrics in a building we have reason to believe is unauthorised.
It depends mainly on the length and difficulty of the cable run, whether your existing consumer unit can take the new circuit or needs upgrading, and whether air conditioning and data are included. The sub-main run and the cabin consumer unit are almost always the biggest part of the cost, not the sockets and lighting. Every job is quoted individually on survey, so ask for a free quote and we will give you a clear, itemised figure.
Not as a permanent supply. An extension lead trailing across the garden is a trip and shock hazard, is not weatherproof, cannot safely carry the load of a heater or air conditioner, and is not a properly certified installation. A garden office needs a correctly sized, buried armoured sub-main feeding a dedicated consumer unit, which is exactly what we install.
Yes. We always fit a small dedicated consumer unit inside the cabin. Splitting the sockets, lighting and air conditioning onto their own circuits means a fault in one will not take out the whole building, and it gives you a local isolator if you ever need to work on anything. It is also the correct way to certify the installation.
Yes, and it is the sensible way to do it. Because we are both the electrician and the F-Gas certified air conditioning installer, the aircon circuit is specified before the cable is laid, the pipework and condenser are planned into the cable route, and both are commissioned and certified in the same project. One survey, one quote, one point of contact.
We almost always use SWA (steel wire armoured) cable, buried to the correct depth and routed to avoid drains, gas lines and likely future landscaping. In some layouts a surface run along a wall or fence line makes more sense. We size the cable for the run length and the load, calculate voltage drop properly, and agree the route with you at the quote stage.
Usually, yes. Older summer houses and outbuildings are often wired off an extension lead or an ageing house radial. We can pull in a proper armoured supply, fit a dedicated consumer unit, and rewire internally to bring the building up to current standards so it is safe and usable as an office year-round.
Yes. We subcontract regularly to Norfolk garden room suppliers and small builders, handling the electrical and air conditioning fit-out on cabins they have supplied and installed. We work to your programme, handle F-Gas certified aircon in the same visit, and issue certification promptly. Call us on 07769 201050 or use the contact form.
Service area
We install garden office electrics and air conditioning throughout Norwich, Wymondham, Attleborough, Hethersett, Thetford, Dereham and surrounding villages. Dedicated service and location pages will follow post-launch.
For full electrical and air conditioning fit-outs on garden offices, garden rooms, studios, workshops and outbuildings anywhere in Norwich, Wymondham, Attleborough, Thetford, Dereham and the wider South Norfolk area. Free no-obligation quote; we normally respond within 24 hours and can usually survey within the following week.
Call us on 07769 201050 Request a free quote
