Problem Addressed

Construction waste.

According to DEFRA’s February 2018 edition of UK Statistics on Waste, in 2014 the UK generated 202.8 million tonnes of waste, and construction, demolition and excavation was responsible for 59% of that number (NBS).

The environmental and commercial arguments for mitigating such profligacy are clear, and one significant solution lies in a relatively simple concept – materials resource efficiency.

WRAP UK, in their document ‘Designing out Waste: A design team guide for building’, state the following: “Using materials more efficiently is a highly effective sustainability strategy and involves a balanced approach, ensuring that at each stage of construction materials are used in an efficient manner.” 

WRAP UK identify, in this document, the crucial contribution designers can make in reducing waste through their design and present five key principles to guide them, accordingly:

  1. Design for Reuse and Recovery
  2. Design for Off-Site Construction
  3. Design for Materials Optimisation
  4. Design for Waste Efficient Procurement
  5. Design for Deconstruction and Flexibility

Solution Overview

The five principles above were instrumental in the development of Akustak®, a ‘zero avoidable waste’, Building Regulations – Part B and E compliant, acoustic modular wall system.

  1. Design for Reuse and Recovery: Akustak®, through its demountable form, enables reuse and recovery more readily than traditional interior wall building methodologies.
  2. Design for Off-Site Construction: Akustak® modules are fully manufactured off site, therefore, off-cuts, that would otherwise go to waste, are stored for future fabrications. Off-site manufacturing also enables:
    • Quick & Easy On-Site Access: Due to its size and weight, Akustak® can be easily handled by one man (as per HSE guidelines) and its stackable design minimises transport and storage requirements.
    • Rapid Installation: Prefabricated and portable, Akustak® transforms interior wall construction into a rapid process of assembly, from 15 m2/ per hour.
    • Meticulous Workmanship: precision engineered in a factory environment, Akustak® accurately interconnects to form pre-specified wall sizes, minimising on-site errors and re-work.
    • Minimised Noise, Dust & Disruption On-site: Akustak® minimises trades and site activities; requiring just 1 to 2 fitters, a cordless drill and basic hand tools. This too enhances health and safety standards on-site, including Covid-19 infection prevention and control.
  3. Design for Material Optimisation: Akustak® modules come in standard dimensions and are formed entirely of parts ‘dimensionally coordinated’ with universal sheet/slab sizes, thereby avoiding/minimising excess cutting and off-cuts. Generally, where off-cuts do arise, they are reusable.
  4. Design for Waste Efficient Procurement: Akustak® is a product developed by Mute Group, which designs and builds solutions in noise control, vibration control and acoustics, across all sectors, with a client base including Alexander McQueen, Disney, HS2, Oxford University and Westminster Cathedral. As such, there is ample opportunity to specify Akustak®, where less resource efficient systems would otherwise be employed.
  5. Design for Deconstruction and Flexibility: Akustak®, through its demountable form, facilitates recovery and reuse, at the point of deconstruction.

Laboratory tested for fire safety (BS EN ISO 1364-1) and resistance to sound (BS EN ISO 10140-2 & 717-1), Akustak® guarantees Building Regulations – Part B and E compliance. Aku125, for example, provides 79 minutes fire resistance and Rw 49 dB airborne sound insulation.

A real-life, single-space case study is used to exemplify ‘financial’ costs/benefits (to the client, only):

A physiotherapist rents a therapy room inside an office complex. The room, across one wall (of 12.5 m2), directly adjoins another company’s office and, as such, lacks the requisite levels for confidentiality. The separating wall needs to be acoustically upgraded, by installing an acoustic independent wall system. The options are:

OPTION 1: Traditional stud-wall construction, suitably acoustically insulated.
OPTION 2: Akustak® acoustic modular wall system.

Note: when the occupant’s tenancy ends, the room must be restored to its’ original state.

Cost Items OPTION 1 Costs: OPTION 2 Costs:
Supply & Fit Cost: £1950.00 £2350.00
Lost Revenue During Installation, i.e. when therapy room is out of use: £1800.00, i.e. therapy room unavailable for 3 to 4 days, with all construction works undertaken on-site. £600.00, i.e. therapy room unavailable for 1.5 days, with majority of construction works undertaken off-site.
Cost to Remove System & Restore Room as Found, i.e. after tenancy: £550.00 £550.00
Cost to Dispose of System, i.e. after tenancy: £150.00 N/A
Cost to Replace System (at new premises), i.e. assuming a like-for-like system is required: £1950.00, i.e. system needs to be rebuilt, from scratch. £700.00, i.e. system can be reassembled.
Total Cost: £6400.00 £4200.00
Total Cost/Benefit: – £2200.00 + £2200.00

Case Study

ENGIE’s ExCEl District Energy Centre provides heat and power to the ExCel Exhibition Centre and surrounding area (London’s Royal Docks)using Combined Heat & Power engines (CHPs). Airborne sound, emanating from these engines, was the cause of continuous noise nuisance complaints from the adjoining dwelling-apartmentsAkustak® was specified to mitigate the problem, from the Energy Centre side. 

Its modular construction and manoeuvrability (particularly at height and within confined spaces) made Akustak® a good fit for this logistically challenging project. The modules were modified to suit the rigours of an industrial environment, including a fire-treated, impact resistant fascia; ensuring the installation is fit-for-purpose, for years to come. 

Pre-completion sound insulation testing demonstrated that, following the Akustak® installation, sound levels in the adjoining dwelling-apartments, due to the transmission of Energy Centre sound, met World Health Organisation (WHO) limits, i.e. in bedrooms at night (23:00 to 07:00), the guidance limit is 30 dB LAeq, 8h and for living rooms and bedrooms during the day, the guidance limit is 35 dB LAeq, 16h. 

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