HUB OF ACTIVITY
Located west of Edinburgh and designed by Page & Park, Pentad is a rare example of innovation in business park design, in both layout and working environment Edinburgh's western edge is populated by business parks of varied quality and age. The most prestigious is Edinburgh Park, masterplanned by Richard Meier and with a website that lists the architects for each building, mostly familiar names, including Page & Park.
Near the opposite end of the spectrum is the area around Pentad, masterplanned largely by chance and designed by cladding manufacturers. Its incremental growth has resulted in an extensive area populated by industrial sheds.
Pentad's client, the EDI Group, was set up as a private company by Edinburgh City Council in 1988, and was originally part of the client/developer team for Edinburgh Park.
With the quality standard already set there, the new Pentad development can be seen as an attempt to push this part of the Gyle area toward the same level. Necessarily, the hope can only be to make Pentad an example influencing its neighbours, albeit in an area felt ready for some change; wider masterplanning is not feasible in the face of established multiple ownership. So today there is an island feel to the Pentad development, an exceptional new neighbour, the more strange because only phase one has been completed, though the whole site has been acquired and cleared.
Phase one comprises a hub building and the first office block of a planned five, comprising a bit less than 20 per cent of the eventual total floorspace of nearly 20,000m 2.What we describe here are both the ambitions and ideas for the whole development and their manifestation in this completed first phase.
The site plan is one of the few innovative UK business park layouts of the past 10 years or so; the other one that comes to mind is Rogers' Chiswick Park (AJ 20.2.03). Pentad is much more urban than its current neighbours, both in the density of development of this 2.7ha roadside site and in the making of its outdoor spaces. Not here an arcadia-aspiring scheme like Stockley Park, with its isolated pavilions ringed by hedged corrals of parking, each linked by tentacles of roads.
Rather, as at Chiswick, primacy has been given to the pedestrian experience, with parking put to the periphery, here mostly concentrated in a band to the rear of the site alongside the railway, organised in two storeys.
This clearing of the decks allows a hub building centrally on the road front with a layout of five blocks radiating from it, creating formally planted triangular gardens between. These are given variety by changes of planting, shape and orientation, and by the exterior treatment of the blocks. Each block has one side in timber with a covered colonnade provided by an overhanging roof, the other side coloured render.
Generally each garden has one timberwith-colonnade face and one render face on opposite sides. (The first block, in phase one, creates the exception to this logic so that both the first and last blocks will show their timberclad colonnaded faces to the road. ) Geometry has been a driver of much of the layout. Notably, the central court has been made a more generous space by setting out the blocks based on a spiral rather than a pinwheel. Colonnaded routes will meet centrally to the scheme, the roofs joined, their trajectories defining a triangular court of seating outside the hub building's eating places. This area is to be sheltered by a large, high-level, triangular glazed canopy. (To keep consistency of colonnade height, those on the last two blocks, which are four storey, will spring from the top of their second floor. ) Today all you see around the central court are the rooftop column stubs for future connection of the central canopy-support columns.
The hub building is one of the marked differences with Chiswick. There the idea of central services is important, with an evident central management presence and a range of business-support services on offer. At Pentad the approach is more straightforwardly commercial. On the ground floor are four retail units, two currently let as a sandwich bar and a Chinese restaurant (being fitted out). One vacant unit is rumoured to be going to a hairdresser - this may be the same hairdresser who has until recently been operating in the area from a van, as have several food-sellers.
The immediate locale is devoid of shops so the new retail units are intended to serve this area; hence their hoped-for viability even in the first phase.
Above the retail units, on the first floor, is office space. A relatively small unit of 470m 2net internal area, it is in a simpler and cheaper market than all the rest of the offices on this development, which the phase one office block exemplifies.
The hub office space specification, though less refined, is well done. And because, at two storeys, the hub will be overlooked by the three and four-storey offices, it is roofed in a copper monopitch, its inclined soffit giving a bit of life to the office volume. Also, with natural ventilation, there is no need for a suspended ceiling;
all the services - lights, smoke detectors, etc - are neatly organised in narrow bands in a jointless plastered ceiling surface.
Standardisation has been a key to making this project work. Beyond the hub building there is very evident repetition in the blocks and floorplates, organised to appeal to funders, while impressively helping to keep costs below £1,000/m 2(excluding external works).
The result of standardisation, though, is conspicuously not bland uniformity. Partly this comes through an experienced knowledge of where to spend money to effect and, especially on the facades, a necessarily restricted palette has been worked hard to produce a lot of variety. Not for this architect the repetitive, though elegant, boxes of Rogers' Chiswick.
Page & Park, it seems, has more fun.
Architect Paul Sutton describes the visual logic of the facades enthusiastically. Each office block has a timber and a render face.On the timber side the emphasis is vertical with vertical boarding and narrow strips of windows with coloured spandrels. On the render side the emphasis is horizontal with windows joined in bands and each floor having a different tone of render, the colour darkening at each floor up the building in a reference Sutton makes to GaudÝ's tiling; it is a contrast to the traditional internal decorative convention of going dark to light from floor to ceiling.
While timber-side windows may look near-randomly disposed at first sight, the underlying logic is tight. There are very few window variants, and all of them sit strictly on the 1,500mm internal grid. The architect chose these Velfac composite windows not just for their performance but also because sightlines are identical whether lights are opening or fixed.
For colours, the games played are reminiscent of the Systems Art of the '60s and '70s.
Over the five office blocks there will be some 25 tonal shifts in render colour, which will gradually change from green to blue as you move clockwise from the phase one office block to the last of the planned five. Spandrel panels take the three colours of their building's render plus the three of the building either side - nine in all (at the ends of the scheme where a building has no neighbour, an extra three-colour band is invented). The architect found the range of body colours available in Sto render more than enough. But when it came to the metal spandrels, getting the subcontractor to deliver the specific colours sought proved problematic, and nearfit RAL colours were eventually used. Sutton pronounces himself happy with the end result and, seen on a clear day, the losses seem more intellectual than visual.
At roof level, single-ply coverings to slopes mask plant areas, which have spare space should tenants want to upgrade HVAC performance. The roof overhangs of the colonnades have dark-stained ply soffits inset with bands of rooflights to avoid too much overshadowing of top-floor windows.
The blocks become more conventional as you approach the office floorplates, but there are touches to savour first in the entrance lobby. It is simple and effective, treated as a transitional space: extensive glazing provides indoor-outdoor contact; the timber external cladding continues through the glazing into the lobby; some lobby walls are also picked out in the green-blue colours; there is space heating but not the institutional standard of air conditioning found in the offices.
Three-storey lobby glazing is achievable with standard curtain walling because of horizontal bracing SHSs at each floor, linked to the steel stair and braced off the concrete floors. It has been used cleverly too to create the illusion of a glass lift; the four shaft sides are actually two fairfaced concrete walls (where the lift motor is concealed) and two faces of the glass cladding. Generally, metalwork is straightforward, though with neat touches such as building light fittings into the stair landing soffits (see Working Details, p3233). Other lighting is indirect. Floors are finished in 600 x 300mm slate, and this material is also used for stair treads and landings.
This approach is carried though to the WCs, which also have indirect lighting and the same 600 x 300mm format, in tiles this time, for floors and walls. It lifts them above the norm.
Empty spec offices don't inspire, but the architect has made a contribution. The composite windows are timber on the inside, set on the outside surface of the wall plane to leave deep reveals, which have been timberlined. One side wall has strips of windows, the other pockets. The windows can be opened in these 15m-deep buildings. Ceilings are finished in acoustic tiles with localised VRV outlets; the ceiling has a wet-plaster edge to make the transition from plastered wall to ceiling grid and to accommodate return air grilles. Lights are on movement detectors.
Floors are raised, awaiting carpets.
At the hub end of this block (and all future ones) is an area of curtain walling, plus a balcony at the first and second floor, providing both a vantage point over the activities of the central court and a jumping off point for a system of pedestrian bridges which will link the block ends. It is difficult to imagine what the coming together of colonnade roofs, canopy, balconies and bridges will be like. It could be a bit cluttered. Or it could have some of the feel of a theatre in the round like the Globe.
The proposed linking bridges are part of the overall strategy for providing letting flexibility. In the phase one block, the core is at one end so a minimum letting is a whole floor (730m 2). Columns are offset in a line 6m from the facade to offer the possibility of a 3m spine corridor. Later blocks have larger floorplates (up to 1,153m 2) and cores are toward the midpoint so that floors can be split in two. For a large letting involving more than one block, the bridges can come into play, as could the architect's sketch ideas for an external core/ entrance to link blocks B and C or D and E.
At this level, Pentad is a straight commercial letting proposition. What the developer has commendably sought to add, and the architect has provided, is an exceptional focus on the qualities of occupants' day-to-day experience of the place, and one that provides a model for dense urban office parks.
SPECIFICATION Phase one office SUBSTRUCTURE FOUNDATIONS, SLABS Pad foundations, strip footings, RC slabs SUPERSTRUCTURE FRAME Steel frame, galvanised where exposed externally UPPER FLOORS Reinforced concrete, profiled metal permanent shuttering ROOF Single-ply membrane on tapered insulation to falls on metal decking ROOFLIGHTS Polyester powder-coated aluminium single-glazed laminated glass STAIRCASES Main stair painted mild steel with natural slate treads and landings, steel-framed glass balustrading EXTERNAL WALLS Cavity construction of two 100mm leaves of dense concrete blockwork with cavity insulation.Finish either coloured acrylic render system or cedar boards on treated softwood framing WINDOWS Velfac composite timber-aluminium, polyester powder coated, double glazed, fully-reversible.Stick system polyester powder coated aluminium frame to double glazed curtain wall screens EXTERNAL DOORS Glass in curtain walls.Timber in timber-clad areas INTERNAL WALLS 100mm dense concrete blockwork INTERNAL DOORS Solid-core oak-veneered doors, with vision panels where required INTERNAL FINISHES WALL FINISHES Offices: taped and filled painted plasterboard on metal framing.Cores:
painted plasterboard and skim.WCs: full-height ceramic tiles,600 x 300mm FLOOR FINISHES Offices:600 x 600mm raised floor system (for carpeting by tenant).
Cores: natural slate on screed on insulation.WCs: ceramic tiling 600 x 300mm on screed on insulation CEILING FINISHES Offices: white acoustic metal tile system; perimeter strip of plasterboard on metal framing system.Cores and WCs: painted plasterboard and skim on metal framing system SERVICES SANITARY APPLIANCES White vitreous china WCs with concealed cisterns.Stainless-steel wash-handbasins set in natural slate vanity tops SPACE HEATING/AIR TREATMENT Offices: above-ceiling VRV units in plenum ceiling void as emitters;
return air grille at ceiling perimeter.Cores: underfloor heating on ground floor, trench heating on upper floors. WCs: low temperature hot water radiators LIFTS Monospace lifts - motor in shaft.Car glazed with stainless-steel finishes and natural slate flooring.Shaft of two walls fairfaced concrete and two walls external glazed curtain walling TENDER DATE First quarter 2001 START ON SITE DATE March 2002 CONTRACT DURATION 12 months FORM OF CONTRACT Two stage tender. Standard SBCC without quantities, with contractor design portion TOTAL COST £3,966,985 (final account, including demolitions and external works) FLOOR AREAS Central building:1,050m 2Phase one office block:2,600m 2CLIENT The EDI Group ARCHITECT Page & Park Architects: David Paton, Paul Sutton LANDSCAPE ARCHITECT Ian White Associates QUANTITY SURVEYOR Summerfield Robb Clark STRUCTURAL, SERVICES ENGINEER Cundall Johnston & Partners TRAFFIC CONSULTANT Colin Buchanan & Partners PLANNING SUPERVISOR Bovis Lend Lease Engineering LETTING AGENTS Ryden PROJECT MANAGER Bovis Lend Lease Consulting MAIN CONTRACTOR HBG Construction Scotland SUBCONTRACTORS AND SUPPLIERS Suspended ceilings Allied Acoustics; architectural metalwork Annandale Design UK; precast concrete stairs Breton Precast (Scotland); louvres Eurolouvre Systems; joinery Firside Joinery; single-ply roofing Grainger Building Services; render, screeding, plasterwork Gratten & Hynds;
brickwork, blockwork Hewcon; scaffolding Interserve Industrial Services;
timber cladding Jamieson Contracting Company; lift installation (office) Kone; lift installation (central building) Otis; window installation Laser Claddings; windows Velfac; mechanical and plumbing Livingston Mechanical Services; curtain walling Linn Tech Scotland; secondary steelwork Harry Lynch & Co; temporary electrics Maxxiom; electrical Arthur McKay Building Services; groundworks, concrete, drainage, hard landscape Meiklem Drainage Contractors; sealant works TC Munro; soft landscaping Premier One (Land Services); fountain installation Ritchie MacKenzie Co; structural steelwork J&D Pierce (Contracts); fire protection R&S Fire & Security; syphonic drainage Ross ADT; demolition Scotdem; metal decking Structural Metal Decks; floor, wall tiling Westcrowns Contracting Services; raised access flooring Veitchi (Scotland); copper roofingWB Watson; decoration Robert Wilson & Sons;
render Sto CREDITS COST SUMMARY Phase one office - costs data based on cost plan, for gross internal area Cost per Percentage m 2(£) of total SUBSTRUCTURE Excavation 5.82 Floor beds 10.62 1.08 Retaining walls, foundations 26.10 2.66 Group element total 42.54 4.34 SUPERSTRUCTURE External walls 176.09 17.96 Internal walls 31.88 3.25 Floors 25.86 Stairs 13.76 Roof 70.04 Frames 87.61 Group element total 405.24 41.33 COMPLETION External wall openings 10.43 1.06 Internal wall openings 12.57 1.28 Balustrading 9.32 0.95 Group element total 32.33 3.30 FINISHES Internal wall finishes 19.31 1.97 Floor finishes 41.84 4.27 Ceiling finishes 31.24 3.19 Group element total 92.39 9.42 MECHANICAL SERVICES Internal drainage 5.57 0.57 Water supply 10.67 1.09 HVAC 169.13 Group element total 185.37 18.90 ELECTRICAL, COMMS, PROTECTION SERVICES Power supplies, lighting 73.41 7.49 Communications 3.31 Transport 21.59 Security 11.11 1.13 Group element total 109.42 11.16 FIXED FITTINGS General fittings 3.06 0.31 Sanitary fittings 13.96 1.42 Group element total 17.02 1.74 SITEWORKS Drainage 3.06 0.31 PRELIMINARIES, CONTINGENCIES Preliminaries 66.56 6.79 Contingencies 26.63 2.72 Group element total 93.20 9.50 TOTAL 980.57 Data provided by Tim Currie at Summerfield Robb Clark EDI Group www. edigroupscotland. co. uk www. pentad-edinburgh. co. uk Page & Park Architects www. pagepark. co. uk Summerfield Robb Clark www. srcltd. co. uk Cundall Johnston & Partners www. cjp. co. uk Colin Buchanan & Partners www. cbuchanan. co. uk Bovis Lend Lease www. bovislendlease. com Ryden www. rydenlettings. co. uk HBG Construction Scotland www. hbgc. co. uk A standard office floorplate, relieved by differing window treatments on either side and a balcony view to the hub at the end