What Is an E-House? Types, Standards and When to Use One
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ETENZ•Editorial Team
What is an E-House? It is a prefabricated electrical room: a factory-built, transportable steel building that holds switchgear, drives, protection and control panels and the systems they need to run. This guide covers what goes inside, the common types and their uses, when one fits a project and when it does not, which standards belong to the enclosure and which to the equipment, what to settle before requesting a quote, and how units are shipped and installed.
An E-House, short for electrical house, is a prefabricated electrical room: a factory-built, transportable steel building that holds switchgear, motor control centers, drives, protection and control panels and DC supplies, along with the HVAC, lighting, earthing and fire systems they need. It is assembled and tested in the factory, shipped in one piece or in sections, set on a foundation at site and connected to the incoming and outgoing cables.
Specifications also call it a modular electrical room, an e-room or, where it holds a substation’s equipment, an E-House substation. Some markets use power distribution center (PDC) or power control room (PCR). Whatever the label, the equipment list sets the scope.
ETENZ is a Shanghai manufacturer of E-Houses for data center, renewable energy, power, mining and industrial projects, and the examples below come from that work.
What is inside an E-House
An E-House has three layers: the building, the electrical equipment and the auxiliary systems. Each can have a different supplier, which explains much of the gap between quotes that look alike.
The building
A steel frame carries wall and roof panels, insulation, doors and a base frame. Full-height equipment doors let line-ups be loaded and serviced, and cables run through a raised floor or cable basement, or on overhead ladders.
The electrical equipment
The project decides what goes in: MV switchgear or GIS, LV switchboards and motor control centers, medium-voltage drives, protection and control panels, DC and UPS systems. Main transformers normally stand outside on their own foundations; dry-type transformers can go inside if the layout allows.
An E-House has no voltage rating of its own: voltage belongs to the equipment inside and the network it serves. ETENZ E-Houses have served installations up to 220 kV, with the switchgear or GIS customer-supplied or integrated within the agreed scope.
Inside the Zhongshan AI data center E-House: solid-state transformer and distribution cabinets on one side, 10 kV switchgear, transformer and LV switchboards on the other, with a service aisle between them.
The auxiliary systems
Equipment heat sets the climate control: ventilation, air conditioning, heat exchange or a mix, sized to the heat load. Lighting, auxiliary distribution and earthing come with it, plus access control and cameras where specified. Fire detection, alarm, releasing and monitoring interfaces are standard ETENZ scope; suppression can be supplied by ETENZ or nominated by the customer.
E-House types and what each is used for
E-Houses have no universal model list. They are usually sorted by the equipment inside and by how the building is made and shipped.
By the equipment inside
MV switchgear E-House: medium-voltage switchgear, metering and reactive-power compensation for a plant’s main distribution or a renewable collector substation. Gas-insulated line-ups go into a GIS switchgear building.
MV VFD E-House: medium-voltage drive cubicles with incoming section and water cooling, for large motors in mining and heavy industry. The ultra-long VFD E-House enclosure for the Julong Copper Mine is 36 m long, the longest single enclosure body ETENZ has built, and its site at about 5,300 m is the highest it has delivered to.
AI data center power E-House: MV and LV distribution, solid-state transformer and batteries in separate units supplied as one set.
Skid-mounted mobile substation: transformer, MV switchgear and DC supply on one skid for emergency and field power, moved as a whole.
By how the building is made and shipped
Container-based: ISO container dimensions, corner castings and a CSC plate, so it lifts and ships as an ordinary container. The three MV switchgear containers in the 40 ft containerized E-House in Germany project were delivered in July 2026 at 24 t gross each.
One-piece custom: sized to the equipment and shipped whole, with no joints to make on site. Beyond container dimensions it travels as an out-of-gauge load.
Sectional: modules shipped separately and joined on site into one room, so the interior is not limited by a single load. The eight-module solar substation GIS building at Huadian Yancheng measures about 22 × 11 × 4.5 m; the 14-module two-tier power E-House stacks control over switchgear modules on the footprint of eight.
How an E-House differs from a site-built electrical room
Both can hold the same equipment. A site-built room goes up first and the equipment is installed inside it afterward; a prefabricated electrical room moves that work to a factory, in parallel with the civil works, and arrives tested. The schedule, quality and safety comparison is in E-House vs site-built electrical room.
When an E-House makes sense, and when it does not
Where it pays off
Difficult sites: remote, cold, high-altitude or short-season locations where skilled electricians are scarce.
A fixed energization date: the building progresses alongside the civil works. The three Zhongshan AI data center E-House units took 45 days from start to shipment and 15 days to place on site.
Repeat builds: phased data center power and multi-site renewable programs can reuse one set of drawings and interfaces.
Equipment makers selling a package: switchgear, drive and STATCOM suppliers can deliver their equipment in an enclosure under their own brand through OEM/ODM.
Where another route is better
The design is still moving: openings, cubicle foundations and cable routes are built from equipment data, so late changes cost more than on site.
The route rules it out: the unit exceeds road, bridge or port limits and the line-up cannot take a joint.
The load is small: a transformer and a few feeders usually fit a compact substation.
The building type is prescribed: the owner’s standard or local code calls for masonry, or a fire-resistance class beyond the available test reports.
Standards buyers usually name
Specifications usually list several standards. Grouping them by what they govern shows who provides the evidence for each.
The complete package: IEC 62271-202
IEC 62271-202 (third edition, 2022) covers AC prefabricated substations rated above 1 kV and up to 52 kV, both high-voltage switchgear stations and HV/LV transformer stations, including structural requirements and test methods. Its type tests treat enclosure and equipment as one design, so a report covers the configuration tested.
Ask early whether the project wants the whole package type-tested to this standard or separate evidence for enclosure and equipment. An E-House serving a 110 kV or 220 kV substation sits above this range and works from the owner’s specification and IEC 61936-1.
The enclosure
IEC 60529 (ingress protection): depends on how doors, cable entries and HVAC openings are sealed. ETENZ builds to IP54 or IP55, set against the actual layout.
ISO 12944 (corrosion): C3, C4 or C5 by environment, with film thickness following the project’s coating specification.
IEC 60721-3 (environment) with ASCE 7 or ISO 4354 (loads). ETENZ’s typical design targets are −40 to +55 °C and about 130 km/h wind, with seismic design to the project zone, confirmed per project.
EN 13501 and ISO 834 (fire resistance), NFPA 72 and NFPA 2001 (alarm and clean-agent suppression), when specified. A fire class attaches to the tested wall, door and penetration assembly.
The equipment inside
IEC 62271-200 (metal-enclosed MV switchgear) and IEC 61439 (LV assemblies): type-test reports, verification records and internal arc classification come from the equipment maker.
IEEE C37.20.2 and UL 508A: named on North American projects for metal-clad MV switchgear and industrial control panels.
The site and the destination market
IEC 61936-1 covers power installations above 1 kV AC and EN 50522 their earthing; both follow the site design. In the EU, CE marking reaches LV assemblies and auxiliary circuits, while IEC 62271 MV switchgear relies on type-test reports. In North America, the local inspection authority decides what it wants for the assembled building, so ask once the site is known.
What to decide before asking for a quote
These decisions move price and schedule more than any single rating.
Delivery scope: Enclosure Only (Interface-Ready), Subsystem Integration, Factory-Integrated Module or OEM/ODM Under Your Brand, ETENZ’s four tiers. See E-House delivery scope.
Equipment and layout: a single-line diagram, dimensions, weight, heat loss and service clearances, what the buyer supplies, and where cables enter.
Site conditions: temperature, humidity, altitude, wind, snow, seismic zone, salt and dust. Altitude changes derating and cooling, so high-altitude E-House design has its own input list.
Protection and subsystems: IP rating, corrosion category, heat load, and who supplies fire suppression.
Transport limits: destination, road and port restrictions, site crane capacity, one piece or sections.
Standards and documents: the owner’s specification, witness testing, and document language.
A quote can start before all this is settled: ETENZ estimates from available data and a typical configuration, and the firm price follows the final design. The engineering RFQ form accepts drawings.
Transport and site installation
Before shipping, ETENZ’s factory stage covers inspection plus energization, interlock and function checks within the agreed scope, with witness testing as an option. The E-House FAT checklist sets out what to inspect.
Transport is a design decision because it fixes the outline. A unit within 20 ft or 40 ft ISO 668 dimensions (2,896 mm high for a high-cube), with corner castings in standard positions and nothing projecting in transit, can carry a CSC plate and move as an ordinary container. A few tens of millimeters over that gauge makes it out-of-gauge cargo.
Out-of-gauge routes and permits depend on the final outline and the destination country’s rules, and the project’s logistics party arranges them. Long or wide buildings can be split: E-House transport covers split lines and joint restoration, and E-House assembly shows a GIS building going up in eight routine lifts.
On ETENZ’s custom-size units the lifting points sit on the base frame, four or eight of them, with eight on any unit longer than 12.2 m. The site’s rigging contractor prepares the lift plan from the project’s lifting drawing.
Site work then usually runs in this order:
The civil contractor completes the foundation and cable trenches.
The unit is lifted into place, leveled, fixed and connected to the site earth.
Sectional units are aligned, bolted and sealed, and busbar, cable and auxiliary links reconnected across the joints.
Items removed for shipping, such as air conditioners, go back on, cables are terminated, and the equipment suppliers and project team commission and energize.
E-House FAQ
What does E-House stand for?
Electrical house: a factory-built building for electrical equipment, also called a prefabricated electrical room or modular electrical room.
What is the difference between an E-House and a substation?
A substation is a function: it switches and transforms power at a network node. An E-House is a building that can hold part of it. In an E-House substation, switchgear and control equipment sit in factory-built buildings while main transformers stay outdoors. A compact substation is a smaller product, with MV switchgear, a transformer and an LV board in one outdoor enclosure.
E-House vs containerized switchgear: what is the difference?
Containerized switchgear is one form of E-House. A containerized MV switchgear E-House starts from an ISO container and stays within its width and height. Longer line-ups or wider aisles call for a custom or sectional E-House.
What is an E-House made of?
Mostly steel. ETENZ’s standard build uses a channel and square-tube frame, a 2.0 mm galvanized steel roof, 1.6–2.0 mm corrugated steel walls and 50 mm rock-wool insulation, with a coated base frame and a C3, C4 or C5 corrosion system, for a structural design life of 25 years. A precast electrical room is the concrete alternative.
What foundation does an E-House need?
Usually concrete strips or piers with a trench for bottom cable entry, designed and built by the project’s civil contractor from the support positions and loads on the E-House drawings.
Can an E-House be used for a data center?
Yes, on the power side: MV and LV distribution, transformers and batteries, beside the halls or inside a larger building, as at the Zhongshan pilot. See data center E-House.
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what is an E-Houseprefabricated electrical roommodular electrical roomE-House substationE-House meaning
