Helping you to understand our industry

Like many industries, modular building has its own language, processes and terms, which can be confusing to some people unfamiliar
with them. Below are the most common terms associated with Algeco products and services as a reference guide.

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Brick Slips

Brick slips are often used on manufactured external walls to replicate the appearance of conventional brickwork; they are generally 20mm thick, while a standard brick is 100mm. The slips are adhered to the metal or plastic frame of an external wall panel with glue and are normally used on permanent modular buildings.

Building Bulletins

Building Bulletins are produced by the Department for Education (DfE) and offer guidance on different topics governing school building specifications, from whole school design schedules to the finer engineering details. Constructing to Building Bulletin standards is perceived as a competitive advantage.

Building Control

England, Wales and Scotland have their own versions of building regulations; Building Control Bodies grant approvals in England and Wales, and Building Standards grant them in Scotland. In England, approval must be granted in order to comply with the Building Act 1984 and the subsequent Building Regulations 2010.

Building Envelope

A building envelope refers to the external walls and roof that form the perimeter or enclosure of a building. The envelope may be constructed from a variety of materials to give a building its own unique design, performance and character.

Building Hire

Hiring temporary buildings is common practice for organisations to procure building space on their own land for short-term needs, usually for three years or less. Hiring consists of paying a deposit, followed by monthly instalments, spread over the length of the hire contract. Hire and rent have the same meaning in this context and are often used interchangeably.

Building Information Modelling (BIM)

Building Information Modelling (BIM) is used to generate and manage data throughout the entire life cycle of the building, from inception and design to demolition and recycling. Models are created that contain not only the building geometry but are data-rich in terms of relations, physical attributes, time, costs and quantities.

The result is a collaborative tool that the project teams can use, clients and the building’s end users. Benefits include:

  • Better coordination, control and flow of information reduce overall risks
  • More accurate cost and programme planning
  • Improved productivity, efficiency and predictability due to central management of teams and data
  • Reduced rework on site.

Building Regulations

Building regulations approval is required to construct certain structures in the UK (this is not the same as planning permission). These regulations ensure that the policies set out in the relevant legislation are carried out properly. See Building Control for the different regulatory bodies.

Building Systems

Building systems is a blanket term used to describe any pre-engineered method of building with pre-defined scoped and configuration limits. Building systems can be volumetric (modular buildings), panel, stick build or hybrid.


Cabin Rental

Cabin rental, also known as cabin hire, is a method of sourcing smaller volumes of space quickly and cost-effectively. See Building Hire for more information.

Cassettes (Floor and Roof)

Cassettes are factory-manufactured panels comprising a series of joists joined together with trimmers or end-joists to form a load-bearing element of the construction. Floor and roof cassettes are typically made from steel or timber and used in residential or low- to medium-rise buildings.

CDM Regulations

The Construction (Design and Management) Regulations 2015 (CDM 2015) replaced the CDM 2007 and covers the management of health, safety and welfare when carrying out construction projects.

The regulations describe the law that applies to all construction projects throughout the entire construction process and what duty-holders are responsible for doing to ensure adequate health and safety practices.


A term used loosely for elements that are manufactured offsite and then assembled with other elements to construct a whole structure or building. Components are a key advantage of modular buildings as their construction requires less disruption, and they can be used to create bespoke solutions.


Design for Manufacture and Assembly (DfMA)

The Design for Manufacture and Assembly (DfMA) is a design approach which uses efficient and effective building design and assembly to create quality construction with reduced resources. These resources are not only financial but might also refer to the amount of labour required, the time taken, the waste created or carbon emissions.

DfMA solutions minimise the cost and timeline of a project while maintaining or improving its quality. It allows for safer deconstruction and greater sustainability in construction, as buildings can then be reconfigured or redeployed.

We used DfMA techniques in creating the UK’s first carbon net-zero restaurant, which was then shortlisted in the Construction News Specialist Awards.


Foundations (Pad)

Pad foundations are pre-cast blocks used to construct foundations rapidly. The load-bearing elements are usually manufactured to a bespoke design and cast in a factory environment.

There are many advantages to using pad foundations, as they:

  • Are versatile and can be used on tarmac, concrete, grass and shingle, to name a few
  • Improve productivity, particularly in inclement weather
  • Require no ground preparation

At Algeco, we offer Jackpad foundations for hire, which are made of recycled plastic and can support modular buildings up to three storeys.

Frame Systems

The terms ‘frame’ or ‘framing’ typically refer to the outline structure of a building but may also describe supporting structures for modular buildings. They can be constructed from many different materials, including steel and timber.


Health Building Notes (HBN)

Health Building Notes advise on best practices for the design and planning of new healthcare buildings, as well as the adaptation or extension of existing facilities. The information in the notes is used to support the briefing and design processes for individual projects in the NHS building programme.

Health Technical Memoranda (HTMs)

Health Technical Memoranda offer guidance on the design, installation and operation of specialised building and engineering technology used in the delivery of healthcare (such as medical gas pipeline systems and ventilation systems).

They apply to both new and existing sites and should be used at various stages from inception to creation and maintenance of a building. All health building notes should be read in conjunction with the relevant parts of the Health Technical Memorandum series.

Hybrid Systems

A term describing a structure that combines multiple distinct systems or materials. Hybrid systems carry no implications for the technical performance of the finished structure.


Jack-leg Cabin

These cabins are modular buildings with steel legs that can be adjusted to suit uneven ground. Jack-Leg cabins can be stacked on top of each other using cranes and are ideal for temporary site accommodation.


Modern Methods of Construction

These methods focus on offsite construction techniques as an alternative to more traditional building processes. Mass production and factory assembly, for example, can produce more structures of better quality in less time.


Modules are individual sections of a modular building with enclosed functional spaces which can be joined with other modules to form a complete modular building.

The term ‘module’ is also sometimes used to describe room modules, which do not have their own superstructure. These are particularly popular for hotels and student accommodation as they can be easily scaled to suit the need.


Offsite Construction

A term largely interchangeable with modern methods of construction, referring to the part of the construction process that is carried out away from the building site. This is often in factory locations or sometimes in specially-created temporary production facilities close to a construction site.


Panelised Building Systems

Panelised building systems describe a planar component, typically manufactured offsite, which may be a key structural component as well as enclosing a functional space. Often used with stick or post components to create a complete building system.

Planning Permission

Planning permission refers to the formal permission required from a local authority to build on land or change the use of land or buildings in the UK. You can contact your Local Planning Authority through your local council.

This should not be confused with building regulations, which are separate.

Portable Buildings

Also known as portable cabins or portable accommodation, these are prefabricated volumetric buildings designed to be moved and relocated quickly and easily. They are semi-permanent in design and construction but are often hired for shorter periods of around three years or less.

Individual portable cabins can be redeployed when customers no longer need them, making them more environmentally friendly. When portable cabins stand on adjustable legs, they are known asJack-Leg Cabins.

Portable Toilet (Mains)

A portable or mobile toilet is a toilet that can be moved around, often by mechanical equipment such as a truck or crane. Mains portable toilets are plumbed into commercial sewerage and water supply networks and require a mains electricity connection. As a semi-permanent solution, they tend to be used on longer-hire contracts of several months or years.

Portable Toilet Mains-Free

Mains-free portable toilets are fully self-contained units that are ready for immediate use. They do not require plumbing and use a waste storage tank instead. Because they don’t need connections, mains-free units are often used in rural locations where mains connections aren’t readily available.

Prefabricated Buildings, Prefabricated Cabins

Prefabricated buildings, or prefabricated cabins, are constructed offsite ahead of time and only assembled onsite. They might be temporary or permanent building solutions.

Pre-Manufactured Value (PMV)

Pre-Manufactured Value (PMV) is the financial proportion of a construction project’s costs from offsite construction. It includes all costs incurred before being installed onsite, including materials, labour, overheads, transport and logistics.

To find the PMV, you simply add up all of the costs from pre-manufacturing until installation, and divide that number by the gross construction costs (which is all pre-manufacturing costs plus onsite labour, all preliminaries, overhead, profit and risk). Then, multiply the result by 100 to get the PMV as a percentage.


Shipping Containers

Shipping containers, also known as storage containers, are large structures made of corrugated steel. They are ideal for storage as they can be installed quickly, are secure and won't dent or buckle.

An International Standards Organisation (ISO) container is designed, created and certified by the ISO for size, strength and durability so that the customer knows they're getting quality.

At Algeco, our storage containers are anti-vandal ISO containers, and we also offer storage container accessories like shelving and spill trays to make the best use of the space.

Site Accommodation

Site accommodation is a collective term used to describe all the space and storage requirements construction contractors have while working on a project. These typically include:

Site accommodation is essential for meeting (CDM) health and safety regulations and guidelines regarding staff wellbeing on construction and building sites.

Structurally Insulated Panels

Structurally insulated panels (or SIPs) are made up of two parallel faces - typically oriented strand board or cement-bonded particleboard - with a rigid core inside that typically consists of polyurethane foam or expanded polystyrene.

SIPS are an affordable and energy-efficient building solution which can even create airtight rooms. As the name suggests, SIPs are all well-insulated.


Timber Frame Building Systems

Timber frame building can consist of wall panels, alongside floor and roof panels (also known as cassettes). They can have open or closed panels.

  • Open panels comprise studs, rails and sheathing on one face, as well as a breather membrane.
  • Closed panels also include linings on the faces of the panel, a vapour barrier and a breather membrane. Closed panels may also include fitted windows, doorways and service routes.

Manufactured in the factory, these cassettes and panels are brought to the site and fixed together to form a rigid, load-bearing superstructure.


Volumetric Modular Buildings

Volumetric modular buildings are large structures consisting of individual modules linked together end-to-end and on top of each other to form complete buildings without the need for an additional superstructure.

Quality control is very important with volumetric modular buildings, so any interior fittings and finishings in the modules will be installed at the factory. When the modules arrive at the site and are joined into one structure, any exterior fittings (such as cladding or roof treatments) can be installed.


Welfare Units

Whether a site has very few workers or thousands, welfare units are a vital part of the project. Some of the welfare units you may need include:

  • Offices
  • Canteens or kitchens
  • Changing or drying areas
  • Toilet blocks
  • Smoking or vaping shelters

These units provide essential functions to all workers or visitors to a site and are necessary to comply with CDM regulations.