Specification

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  1. Building Specification

    1. Structure

      The existing building structure is predominantly of steel frame construction with clay pot floors. The steel beams are encased in concrete and the columns are encased in brickwork. A portion of the building to the south of the site is supported on loadbearing masonry party walls. The mansard roof is of concrete construction.

      The new building structure is of steel frame construction using slim universal column section supporting steel beams with shelf angles. The steel beams support composite steel deck concrete slab.

    2. External envelope

      The majority of the existing Portland Stone masonry external envelope is retained and cleaned/repaired. A new external wall with rainscreen cladding and curtain glazing is installed to the rear deck. Where the new extension meets the party wall of 47 Margaret Street, the external envelope is solid glazed brick work with internal plaster skim, insulation and dry lining.

    3. Office design criteria

      Foor occupancy Office floors, WC accommodation and building services have been designed to an average occupational density of 1 person per 10 sq m.
      Floor occpupancy All office floors are served by two escape stairs with an MOE Occupancy factor 6 sq m / per person.
    4. Dimensions

      Clear ceiling heights Preliminary indicative clear headroom subject to further survey information:

      Sixth floor 2.30m
      Fifth floor 2.50m
      Fourth floor 2.40m
      Third floor 2.40m
      Second floor 2.80m
      First floor 3.06m
      Ground floor The floor to ceiling height will be 4.0m.
      Raised floor zone Average void ranging from 65-150mm.
      Lighting zone The lighting zone is nominally 100mm but varies depending on the different areas.
    5. Floor loadings

      The following loads (kN/m2) have been adopted in the design:

      Office areas (total) 4.0 (3.0 imposed + 1.0 partitions)
      Flat roof 1.5
      Access walkways at roof 1.5
      Roof plant 5.0
      Basement plant area 7.5
    6. Acoustics

      Offices NR 38
      Washrooms NR 40
      Reception NR 40
  2. Building Finishes

    1. External

      Regent Stree Entrance

      New patinated bronze framed automatic sliding glass doors.

      Refurbished signage and external lighting.

      Integrated Public Art in Portland Stone – Vong Phaophanit and Claire Oboussier.

      Margaret Street entrance New timber doors with access control system for redirecting enquiries to main entrance.
      External elevations

      New bronze framed shop windows at ground level to be provided to retail areas.

      New Critall double glazed steel framed windows.

    2. Internal

      1. Reception

        Walls

        Linear feature lighting.

        North wall and lift screen are Portland Stone, engraved with artwork by Vong Phaophanit and Claire Oboussier.

        White back painted glass to the riser access doors.

        Painted plasterboard with powder coated skirting elsewhere.

        Floor Colombino Italian sandstone with honed finish.
        Ceiling Painted plasterboard with skylight over feature stair.
        Skirtings White powder coated.
        Furniture Leather front panel desk with American Walnut work surface and patinated bronze top.
        Lifts Stainless steel lift reveals and entrance doors.
        Stair 1.2m wide feature stair to first floor with skylight above. Colombino Italian sandstone treads and risers with stainless steel inserts. Central slatted feature in American Walnut. Bronze balusters and support rail with timber core handrail with saddle stitched leather and bronze end caps.
      2. Offices

        Walls Painted plaster/plasterboard (skirting by tenant).
        Ceiling Suspended plank metal 325 x 1350mm tiles with plasterboard perimeter.
        Floors 600mm x 600mm metal tile raised access floor.
        Solar Control Fabric blinds – installed as part of Cat A to the roof lights on 6th floor.
        Windows New Critall metal windows.
        Doors Metal profiled glazed doors to main core and secondary stair with stainless steel pull handle and channel for access control unit (to be fitted by tenant).
        Ironmongery Stainless steel throughout.
      3. Lift Lobbies

        Flooring Colombino Italian sandstone.
        Walls White painted plaster with powder coated skirtings.
        Ceilings White painted plasterboard.
        Doors White doorsets with stainless steel ironmongery.
        Signs Bronze floor numbering.
      4. Washroom and Shower

        First to sixth floors

        Four number unisex self contained WCs.

        One number accessible WC with provision for future wet room shower.

        Flooring Domus DFH 100 X 600mm tiles.
        Sanitary ware White glazed porcelain.
        Walls Plasterboard and Zodiaq ‘Gravel Grey’ panels (back painted glass vanity panels and mirrors in cubicles).
        Ceiling Painted plasterboard
        Doors White withi European Walnut inserts and lippings.
      5. Staircases

        Main staircases Sprayed steel stringers and trays with carpet treads and stainless steel handrails.
        Secondary staircase Existing terrazzo stair to be repaired and finished with carpet. Existing handrail and balustrade to be reconditioned.
    3. Lift interiors

      Walls Back painted iron glass with DDA compliant mirror and rail.
      Floor Colombino Italian sandstone to match reception.
      Lighting Recessed linear fittings.
  3. Mechanical services

    1. Services design criteria

      Winter temperature 21°c +/- 2°c
      Summer temperature 24°c +/- 2°c
      Occupancy 1 person per 10m2
      Base Cooling loads

      Lighting power: 12 W/m2 at 400 lux

      Small power: 25 W/m2

      Ventilation rates Offices: 14 L/s (incl. 2 L/s allowances for meeting rooms)
      WCs 10 air changes / hour extract
      Enhanced Small Power Allowance 5w/m2 (30W/m2 total @ 90% diversity)
    2. Heating, cooling and ventilation

      The building incorporates a variable refrigerant flow (VRF) system comprising concealed fan coil units above the ceiling in the first to fourth floor offices with external condensers at roof level (fifth and sixth floor offices will comprise of a mix of chassis fan coil units within the central bulkhead and perimeter cased floor standing VRF fan coil units). The fan coil units in each office demise are connected to separate external units allowing individual control and metering.

      Fresh air and extract ventilation provided to the offices via a central air handling unit located at roof level which will deliver conditioned fresh air to the back of each fan coil unit and extract vitiated air via galvanised steel duct work system.

    3. Lift installation

      Three no. 12 person DDA compliant lifts serving ground to sixth floors.

      One of the above serves basement level and double as goods lift (1600 x 1400 x 2200mm).

      Basement lift is also a fire fighting lift.

    4. Window cleaning and maintenance access

      Window cleaning

      First floor to sixth floor windows to be cleaned by Cherry Pickers.

      The majority of the rear curtain glazing to be cleaned by pole with some areas on the party wall cleaned by rope access.

    5. Fire protection services

      Portable fire extinguishers are provided throughout the building in accordance with BS 5306.

    6. Fire alarm and detection installation

      A new analogue addressable fire alarm system is provided which complies with BS 5839. Manual call points at final exits and escape routes, fire alarms throughout the building and automatic detection in line with BS 5839 category L2, installed.

  4. Electrical installation

    1. High and low voltage installations

      Single power supply to the building from a new UKPN substation infrastructure installed within the confines of the site.

      Power is discharged at low voltage via a main switchroom located at basement level. Two rising busbars with three tap-off units at each tenant cupboard installed. One of the tap-offs used to feed lighting and small power composite MCB distribution boards. The remaining tap offs will remain spare. All distribution boards, panels and major plant monitored by a digital meter linked to a metering system.

    2. Small power

      The supply to the floor and the distribution board is designed with an allowance of 25 W/m2 plus an additional 10 W/m2 (diversified load) for the tenant fit out.

      See 1.5

    3. Lighting

      Lighting installation is compliant with LG7 standards.

      The installation comprises recessed LED linear luminaires.

      A lighting control system is provided to allow future flexibility to suit tenant fit out requirements.

      The following levels of illumination are designed as follows.

      General office 400 lux (at desk height)
      Reception desk 300 lux (reception area 200 lux)
      Lobbies and stairs 150 lux
    4. Access control

      Access control provided to restrict un-authorised access in to the building.

  5. Environmental perfromance

    1. Sustainability

      Rainwater harvesting incorporated with a central treatment storage tank buried in the basement area to provide a proportion of WC flushing.

    2. BREEAM

      A BREEAM target of ‘Very Good’ through the refurbishment of the building.

  6. Tenant provisions

    1. Cycling

      14 cycling spaces provided via a dedicated entrance from Margaret Street with lift to basement.

    2. Lockers

      14 Venesta 855 x 308 mm lockers are provided in the basement. There is a separate drying cupboard in the cycle store.

    3. Showers

      Two showers are provided at basement level. The disabled WC on each floor, have the ability to be converted into a wet room shower & toilet.

    4. Standby power

      Space allocated on roof for tenant generator.

    5. Communications

      Cable ducts into the building from local infrastructure are provided to the telecom rooms with diverse routes to tenant areas. Space for satellite dishes at roof level.

    6. Teapoint

      Each floor is serviced by two rising extract ducts and water supply and waste points on either side of the core in order to facilitate tenant fitout of a teapoint.

    7. Subdivision

      The cooling and heating is provided to the offices based on an anticipated multi-tenancy arrangement of two tenants per floor.