View source for ARM Headquarters, Cambridge

==Article in [http://www.newsteelconstruction.com/wp/wp-content/uploads/digi/NSCFebruary2017digi/index.html#/14/ NSC February 2017]==
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'''Offices armed with steel design'''<br>
A renowned high-tech multinational company is expanding its Cambridge headquarters with the [[Construction|construction]] of a new [[Multi-storey_office_buildings|office facility]].<br> 

Currently under [[Construction|construction]] at the Peterhouse Technology Park on the southern outskirts of Cambridge, ARM, the multinational semiconductor and software design company, is in the process of expanding its headquarters with the [[Construction|construction]] of a new 1,900m<sup>2</sup> [[Multi-storey_office_buildings|office facility]]. Located adjacent to the company’s existing HQ, the new facility will be ready for occupation this autumn and will enable ARM to increase its headcount in Cambridge to 3,000 people.

Mike Muller, Chief Technology Officer and Co-Founder of ARM, says: “We are making a significant investment at our headquarters in Cambridge to help us deliver the next phase of company growth. The expanded Cambridge campus will house many of the ARM engineers designing next generation processors and software that will power silicon chips supporting the rise of smart cities, for consumer devices and the communications network. There are 86 billion ARM-based silicon chips in the world and that number is growing as the built environment, transportation, homes and offices become increasingly connected.”

Having started on site in early 2016, main contractor Kier is constructing a highly distinctive facility that will be clad with [[Facades_and_interfaces#Curtain walling|curtain walling]] and bespoke vertical aluminium brise soleil [[Facades_and_interfaces#Solar shading systems|solar shading]], which will form a 6m-high saw tooth pattern.
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Early works for Kier included a lengthy groundworks scheme to prepare the previously greenfield site. This involved bulk excavation, ground stabilisation and the installation of pad foundations for the [[Braced_frames|steel frame]]. A large gas main runs across the site and a steel [[Bridges#Truss bridges|Bailey Bridge]] had to be installed to span this important conduit and allow [[Construction#Mobile cranes|cranes]] and other plant to drive across it.

The three-storey facility consists of two similar buildings, known as ARM A and B, that are interconnected by a first-floor [[Design_of_steel_footbridges|walkway bridge]]. ARM A will also on completion be connected to the existing ARM HQ via a ground floor covered walkway.
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During the [[Design|design]] stage a number of framing solutions were considered, but steelwork was chosen because of its [[Multi-storey_office_buildings#Speed of construction|speed]] and [[Multi-storey_office_buildings#Value for money|cost-efficiency]] according to Kier. “[[Service_integration|Integrating the services]] within the floor depth and keeping the height of the buildings down so that they match the surrounding structures were also important criteria for the [[Design|design]],” adds Ramboll Engineer Helen Leung. “So we opted for a [[Composite_construction|steel composite]] design throughout both buildings using 600mm deep [[Steel_construction_products#Cellular beams|cellular beams]], to accommodate the services, supporting [[Composite_construction#Composite slabs|metal deck flooring]].”

The two [[Braced_frames|steel-framed]] structures are similar in [[Design|design]] with the only major difference being that ARM A measures 85m long × 55m wide, making it 6m longer than its neighbour. [[Concept_design#Structural options for stability|Stability]] for the steel frames is derived from their [[Concept_design#Concrete or steel cores|braced cores]], with both buildings having a main centrally positioned lift core and smaller staircase cores at either end.

“[[Construction#Steel erection|Steel erection]] began on these main [[Concept_design#Concrete or steel cores|braced core]] areas on each structure,” explains Caunton Engineering Contracts Manager Michael Firth. “Once they were [[Construction#Steel erection|erected]] we had a rigid box and we were then able to proceed in two directions with two gangs away from this [[Concept_design#Concrete or steel cores|stability-giving core]] to complete each building.” [[Construction#Steel erection|Steel erection]] initially began on ARM B as groundworks were still ongoing on the other part of the site. However, within a couple of weeks Caunton Engineering was able to work simultaneously on both buildings using up to four [[Construction#Mobile cranes|mobile cranes]].

The heavily [[Concept_design#Concrete or steel cores|braced cores]] feature [[Steel_construction_products#Standard open sections|UC sections]] as these areas of the steelwork will be hidden behind walls in the completed buildings. Elsewhere in the scheme, [[Steel_construction_products#Structural hollow sections|circular hollow sections]] have been used as most columns will be left exposed, with the perimeter members in full view behind the [[Steel-supported_glazed_facades_and_roofs|glazing]].
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Either side of the main lift [[Concept_design#Concrete or steel cores|cores]], both buildings feature [[Steel-supported_glazed_facades_and_roofs#Atrium Roofs and Sky lights|atriums]] that will be spanned by rooflights to create voids that will allow natural light to penetrate the inner parts of the buildings. The office spaces are arranged either side of these voids on ground and first floor, with one row of internal columns either side of the [[Steel-supported_glazed_facades_and_roofs#Atrium Roofs and Sky lights|atriums]]. The office spaces have spans of 9m and one of 10.5m, offering plenty of interior space.

Cantilevering walkways, spanning adjacent to the main lift [[Concept_design#Concrete or steel cores|core]], provide access between the two sides of each building.

The perimeter columns are predominantly spaced at 6m centres, with the exception of the end two bays on each building where the [[Concept_design#Floor grids|grid]] increases to a 9m wide spacing.

The second-storey of each building accommodates plant areas as well as more offices, although these working spaces are set back to provide rooftop terraces.

The ARM HQ is scheduled for an early 2018 completion.

==Car parking==
The overall project also involves Kier constructing two [[Car_parks|multi-storey car parks]], both of which are [[Braced_frames|steel-framed]] structures.

The first of these, providing 268 spaces over two levels, was handed over in January and was [[Construction#Steel erection|erected]] by Bourne Parking (part of Bourne Construction Engineering). Requiring 400t of steel and 400 [[Floor_systems#Precast units|precast floor slabs]], Bourne Parking completed its work in a 15-week programme. As well as [[Construction#Steel erection|steel erection]] and the installation of the floor slabs, the company’s work also included installing two precast staircases and the [[Building_envelopes|cladding]].

Once this structure was handed over, Kier was able to close an existing on-site surface car park while still keeping sufficient parking spaces available for ARM employees during the [[Construction|construction]] programme. This plot of land is now being made ready for the [[Construction|construction]] of the second 500-space structure.

{|class="wikitable" width="400"
|-
|'''Architect'''||Scott Brownrigg
|-
|'''Structural Engineer'''||Ramboll
|-
|'''Steelwork Contractor'''||Caunton Engineering
|-
|'''Main Contractor'''||Kier
|-
|'''Main Client'''||Coal Pension Properties
|}

[[Category:Case studies - Multi-storey office buildings]]