Technical · Reference design T-03
Prefabricated E-Houses & Power Modules
A prefabricated e-house exists to shelter equipment somebody else has already specified. Ours is made on your plot from precision components, and the line around our order is agreed first.
Decision Rooms
Four decisions that shape the enclosure
Equipment scope
Which side of the wall the switchgear is bought on
The building is ours. The switchgear, transformers, protection, control panels and auxiliaries are specified by your electrical consultant and bought against a schedule of their own. Some projects want both under one order; some keep them apart deliberately, because the equipment is already inside a supply agreement. Decide it before the enquiry, because it changes what a quotation can answer.
Where the two orders meet is a list, not a sentence: earthing and bonding, small power, lighting, the cable route through the floor, the fixings that carry a panel’s weight, the door that has to open past it. The list is short and it is written down. An unwritten interface is the item that stops a commissioning date.
Cable entry
Where the cables come in, and what that fixes
Cables enter from below over a trench or a pit, or from above through the roof. The choice belongs to your electrical layout rather than to the building, but the building has to be set out for it, so it is fixed before the base is drawn. Change it afterwards and the floor build-up, the base and the internal arrangement all move together.
Door face
Which elevation the equipment goes in through
One face carries the doors that admit a switchboard or a transformer; another carries the door a person uses on an ordinary morning. Putting both on the same elevation shortens the building and crowds the approach. Splitting them lengthens it and keeps operators clear of a lifting route. Your electrical layout and your safety case decide it together, on the plan.
Who specifies
The consultant who names the standard, the engineer who approves it
Ingress, fire, temperature, seismic and short-circuit figures are never ours to state. Your consultant names whichever published standard governs the installation, your engineer approves the design against it, and the enclosure is manufactured to that specification. Settle who holds that pen at the start, because everything this building has to prove is written in their document.
Your engineer’s approval is not a formality to be routed around. The design is issued to them, they mark it, and the marked version is the one that gets built. Where a standard is named late, the change is priced against the register rather than absorbed quietly, so the document read at the end of the job is the one that was read at the start.
The plot inside a working plant
The plot is rarely empty. An e-house usually stands inside something already working — a substation yard, a process plant, a solar or wind site, a pumping station — and the ground around it belongs to somebody who is running it. What that site can spare, and for how long, shapes the programme more than the building does.
What you see first is a long dark base and a blank wall above it. Three of the four elevations give nothing away: no glazing, no entrance, no gesture towards a visitor, because there is no visitor. The building turns its whole face to the yard it serves, and the yard reads it as one more piece of plant.
Then the laydown. Material has to be set down somewhere dry, in the order it goes up, within reach of the plot, and it has to sit there without blocking the plant’s own traffic. Where that area is, and how long you can hold it, is a question for your site manager before it is a question for us.
How the envelope goes together
Come close and the method shows. Steel members are fabricated to the drawing and stood up on your plot; the walls arrive as manufactured panels and are screwed to that frame; the roof build-up goes on over them. Every component travels flat, banded and labelled, and the enclosure is put together where it will spend its life.
Nothing is applied wet at the panel joints, so a junction is found with a finger rather than made good with a trowel. On an industrial plot that matters for an unglamorous reason: a dry joint can be opened. A panel can be taken off to pass equipment through and fixed back afterwards, which is not true of a wall that was cast.
What the outside is finished in is a project decision and it is taken late. No material family has been assigned to this building, so this page names none. Cladding, roof finish and colour are chosen against your plant’s own standards and its maintenance regime, and they go into the quotation rather than being assumed here.
What the enclosure is asked to hold
The internal arrangement is not a house style. It comes off your equipment schedule: what stands against which wall, how far it has to be drawn forward to be maintained, which item needs a door wide enough to pass it, where a person stands to operate it, and where nobody may stand while it is live. Read the schedule and the plan is mostly written.
Heat is the second reading. Equipment inside a closed building raises the temperature around it, and that figure comes from the equipment’s own data sheets, which we do not own. Your electrical consultant states the load; the building is then drawn around the ventilation or cooling that follows. Neither of those numbers is invented on this side of the boundary.
Weight and route come third. A transformer or a switchboard has a mass and a path from the door to its final position, and both belong on the drawing before the floor build-up is settled. The heaviest single item usually decides the base, and it is worth naming that item in the first conversation.
The threshold, and the widest thing that has to pass it
C01
The service face, with every door closed
The service face and its doors
The fourth face is the one that does the work. Where the other three are blank, this elevation carries the equipment doors: leaves wide enough and high enough for the largest item on your schedule to be brought in upright, with the threshold flush so nothing has to be lifted over a step on the way through.
Beside them sits the personnel door, narrower, on its own escape route, and above the line of both runs the ventilation or cooling that your consultant’s heat load calls for. The face reads as a working elevation: doors, louvres, a light, a bonding point, and nothing put there to be admired.
At the foot of it the base steps forward for the cable entry, and the trench or duct bank arrives at that point rather than anywhere along the wall. Everything about that elevation is set by the schedule, which is why it is the last face drawn and the first one a maintenance team looks at.
The buyer’s folio
The package engineer’s folio
Four short chapters for a package engineer: where our scope stops, what the equipment schedule decides, how the enclosure is put together on your plot, and what must be settled before any quotation is honest.
01The boundary is the productWhy an enclosure is bought, what surrounds it on a working site, and why the line around our order is the clearest part of it.
An e-house is bought for one reason: the equipment inside has to keep working, and the weather, the dust and the people outside must not reach it. Every other requirement follows from that one. The building is not the point of the purchase, which is exactly why the boundary around it has to be the clearest part of the order.
The building is not the point of the purchase. Its boundary is.
That is also why this page carries no capacity, no rating and no dimension. None has been drawn for a building nobody has briefed yet. A page that publishes a figure now is publishing somebody else’s project, and the engineer reading it will ask where the figure came from within a minute of finding it.
An unwritten interface is the item that stops a commissioning date.
IN SHORT — Ours is the enclosure, yours is the equipment, and the list between them is agreed before anything is ordered.
02The schedule decides the roomClearance, heat, weight and the door — four readings taken from a document the buyer already holds.
Maintenance is what the room is judged on five years later. The clearance in front of a panel, the space to withdraw a device, the route a two-person lift takes back to the door and the light over the working face are all settled at plan stage. They are expensive to argue about afterwards, when the equipment is energised and access is a permit rather than a walk.
The internal arrangement comes off your equipment schedule, not off ours.
None of this requires us to know your process. It requires the schedule. Where the schedule is not final, the enclosure is drawn around the largest arrangement it may have to hold, that assumption is written into the quotation in plain words, and it is revisited once the equipment order closes.
Name the heaviest item in the first conversation.
IN SHORT — Clearance, heat, weight and the door — four readings, all of them taken from your own document.
03Made on site, from componentsThe frame, the panels and the dry joints, and the one elevation that has to do all the work.
The frame, the panels and their fixings take their engineering from a licensed professional working on your project, to loads your engineer has stated. No span, gauge or load figure appears on this page. The only one worth having is calculated for your plot and carries the name of somebody who stands behind it.
Three elevations give nothing away. The fourth one does all the work.
Alongside the drawings we draw up an interface register with you before anything is ordered: three columns — ours, yours, and by others — with one owner against earthing, small power, lighting, containment, the incoming route, fire detection, ventilation, monitoring, door hardware and attendance at commissioning. Its value is the rows nobody claims.
A dry joint can be opened. A wall that was cast cannot.
IN SHORT — Frame, panels and roof arrive as material, and the register we draw up with you names an owner for everything they touch.
04What is settled before anything is madeThe five inputs, the two supplied figures, the sheets that follow the design, and what we refuse to claim.
What we ask for is short. The equipment schedule with weights and heat loads, the direction the cables enter from, the access and laydown your site can hold, the standards your consultant is specifying to, and the date the plant can release. Five inputs, and an answer comes back about your plot instead of about a product range.
Five inputs, and an answer comes back about your plot instead of about a product range.
Two numbers on this page belong to the manufacturer behind the studio and not to your enclosure: over a hundred delivered projects, and an assembly programme running sixty to ninety days on site. Each is restated per building when we quote. Neither is a promise about ground nobody has surveyed, and neither is a lead time for equipment bought under another order.
We do not claim a building like this can only be made this way. It can be built conventionally, and on an easy plot beside a road it often is. The argument for this method is a plot inside a working plant, a site far from labour and material, and a programme that cannot absorb a wet trade.
None of the sheets is drawn yet, and this page will not pretend otherwise.
Where that argument does not hold, it does not hold, and we would rather say so at the first meeting than discover it at the third. An enclosure on level ground beside a main road, with a contractor already mobilised and no shutdown to work around, is a job somebody else may do better.
IN SHORT — The boundary, the register and the input list carry the conversation; the sheets follow the design.
Questions to close before the enquiry
Do you supply the switchgear as well as the building?
Not unless it is written into your order as a separate line. The enclosure — frame, envelope, doors, finishes — is ours. Switchgear, transformers, protection, control panels, cabling and auxiliaries are specified by your electrical consultant and bought against their schedule. The interface register drawn up with you names every point where the two orders meet.
Can it be built while the plant keeps running?
That depends on your permits rather than on our method, but the method helps. Material arrives flat on ordinary transport and the enclosure goes together where it will stand, so nothing habitable has to cross a live yard. Access, the laydown area and any shutdown window are agreed with your site manager first.
What ingress, fire or temperature rating do you state for the enclosure?
None as ours. Where a published standard applies to your installation, your consultant names it and your engineer approves the design against it; the enclosure is then manufactured to that specification. We publish no rating, no capacity and no performance figure here, because none has been calculated for a building nobody has briefed.
What actually arrives on site?
Material. Steel members made to the drawing, wall panels, roof build-up, cladding, doors, fixings and internal finishes, banded on pallets and labelled in the order they are needed. Nothing habitable is lifted off a lorry. The base is set out first, the frame is stood up, the panels are screwed on, the roof goes over.
What do you need from us before you can quote?
The equipment schedule with weights and heat loads, the direction the cables enter from, the access and laydown your site can hold, the standards your consultant is specifying to, and the date the plant can release. Those five turn an enquiry into a document about your installation rather than about ours.
Can the enclosure be taken apart and re-erected somewhere else?
Tell us at the briefing and it becomes a design input. Components are screwed rather than bonded, which makes dismantling possible rather than promised, and the joint, fixing and finish decisions all change if you intend to use it. We do not advertise it as a property of a building that has not been designed.