Commercial buildings Building types

Before looking at the constructional characteristics of commercial buildings it would be useful to classify their main forms of construction. They can be divided into two broad groups: unframed and framed.

• Unframed Solid or cavity wall construction (usually up to a maximum of six storeys) or column and slab construction (usually up to a maximum of about 12 storeys).

• Framed Steel or reinforced concrete - skeletal form for multi-storey blocks.

Table 2.5 Typical forms of modern construction

Type of construction Original era Comments

Table 2.5 Typical forms of modern construction

Type of construction Original era Comments

Bunched/bundled tube

1970s

A form of steel or concrete-framed construction suitable for very high-rise buildings (Orton, 1992).

CLASP system

1950s

A form of system building for low-rise non-residential properties such as schools (see Chapter 9).

Column and plate

1950s

Once popular technique for multi-storey blocks of flats and offices.

Modular panel

1960s

Wall and floor panels prefabricated as storey high units and connected together on site. Large panel system was once a very common method of non-traditional construction for high-rise flats.

Modular pod

1980s

Prefabricated room-sized modules (often fully fitted out) bolted together on site to form the required plan shape and number of storeys. The pods are then clad externally with a single skin of brickwork or cladding panels to give the building the desired finish. They can also be used in 'renovation' projects (Lawson, 2001b) -see Chapter 9.

'No-fines' concrete

1950s

A popular form of non-traditional housing of solid wall construction, usually used for low-rise blocks but was used as the infill wall material in some high-rise flats (see Chapter 8).

Portal frame

1940s

Suitable for low-rise factory and warehouse properties, and for top storey extensions to flat-roofed commercial buildings (see Chapters 7 and 9).

Slip form wall and slab

1980s

A form of industrialized construction used for commercial buildings such as hotels.

Skeletal frame

1900s

'Stick-built' construction where members are connected on site (Lawson, 2001a). Very common conventional method for low-rise and multi-storey commercial and industrial buildings. It can be used as the superstructure for extensions.

Tunnel form reinforced concrete construction

1980s

This is a method of cellular construction in which a structural tunnel is created by pouring concrete into steel formwork to make the floor and walls.

The constructional characteristics of commercial buildings are varied. Generally, however, they are of either concrete or steel frame construction clad with stone or lightweight cladding. Table 2.6 summarizes the main differences.

Other adaptation issues Site usage and density

A building or group of properties that covers more than about 60 per cent of a site does not allow much room for on-site access, lateral expansion or increased daylighting. The original intensity of use of the site might also have an impact on the permissible density of the building once it is adapted.

Table 2.6 Characteristics of different commercial building types (Martin and Gold, 1999)

Period

Advantages

Disadvantages

1900-preWW2

May have high ceiling.

May be listed (resulting in delays due to

Designed for natural

negotiation with English Heritage/

ventilation. Narrow floor

Historic Scotland).

plate aids this. Add solar

Structural partitions - inflexible

shading and spot cooling

space, poor circulation, poor

in high heat gain areas. Heating,

insulation. Low floor loading

power and communications

(may not accommodate current

routed around perimeter.

loads without strengthening).

Late 1950s/1960s

Open plan layout.

Low floor-floor height.

Designed for natural ventilation.

Large glazed areas leading

Narrow floor plate aids this. Add

to high heat gain.

solar shading and spot cooling in

Low floor loading (may not

high heat gain areas. Heating,

accommodate current loads

power and communications routed

without strengthening).

around perimeter.

Relatively lightweight partitioning.

Poor insulation and high air

infiltration rates.

Single glazing.

Addition of raised floor complicated

around lifts and stairwells. Routing

ducts and pipework may be difficult.

1970s

Larger floor-floor height than 1960s

Lightweight construction. Possible

(for services).

high air infiltration through

Deep plan, a disadvantage due to

facade, poor insulation. High heat gain

need for air conditioning and

through fully glazed facades.

artificial lighting.

Open plan layout.

1980s

Larger floor-floor height.

Lightweight construction.

Raised floor for services.

Over-specified ventilation and

Open and deep plan layout.

air conditioning - difficult to

High electrical power capacity.

control.

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