Nottingham Apartments, Retrofit Conversion

Project Overview

Background

In May 2018 local authority planners granted consent for the £16 million redevelopment of an iconic site close to Nottingham city centre, overlooking the River Trent. The proposed Waterside development would be created through the refurbishment and rooftop extension of the well-known Rushcliffe Civic Centre, and through the construction of two new 11-storey residential towers.

The mixed-use development, once complete, would deliver 125 residential units (a mix of one-, two- and three-bedroom luxury apartments) together with office space, retail space, a restaurant and bar.

Brief:

Permarock’s role in this ambitious high-rise scheme was to support the project team with the design, installation and inspection of a non-combustible external wall insulation system, suitable for use on premises with a floor height of 11 metres and above. In addition to meeting all relevant fire safety standards, the chosen system would need to demonstrate excellent thermal properties and to produce an attractive, durable finish.

Design and Specification:

Permarock’s technical team worked with the design team to agree the following specification for the external wall insulation system:

When combined with Permarock SiliconeUltra K finish, Permarock Mineral Fibre EWI systems achieve an A2-s1,d0 reaction to fire classification and can be used on buildings of any height.

The Permarock Mineral Fibre insulation was supplied in boards measuring 1200 mm x 600 mm. Generally, they were installed to a thickness of 120 mm but other thicknesses were used as necessary to complete the detailed design. All insulation boards were affixed using a cement-based adhesive and galvanised steel screws.

The use of both adhesive and mechanical fixings adds an important level of safety; it helps to ensure that in the event of a fire, the system remains securely attached to the building and presents no risk of falling debris to fire and rescue teams or to residents who may be evacuating the building.

Permarock SiliconeUltra K Finish is a flexible textured render that is available in a wide range of colours, all of which resist fading and the accumulation of dirt. The finish is highly durable, resistant to severe wind loads and capable of protecting buildings in all weathers. It also helps to maintain airtight facades, which helps to prevent heat-loss through the interfaces between walls and window frames, ducts and other penetrating features.

Performance and Sustainability

Permarock Mineral Fibre insulation is manufactured to EN 13162 and is CFC- and HCFC-free. It has zero Ozone Depletion Potential and zero Global Warming Potential.

Permarock Mineral Fibre External Wall Insulation systems have low embodied energy and are BIM Level 2 compliant. They exhibit thermal conductivity of 0.036 W/mK, and have an Ecopoints score of 0.10 (m2). This is classified as an ‘excellent’ rating. When used as part of a suitably designed low-carbon project, they enable very low U-values to be achieved.

Planning and Project Delivery

Permarock technical staff supported the design team by providing visualisations, material samples and colour samples, together with fire safety data, BIM Object files and thermal calculations. They also performed pull-out tests to determine the integrity of the cement particle board substrate and, consequently, the suitability of the proposed fixings. As work progressed, they also conducted on-site quality inspections and technical assistance as required.

Result:

Permarock’s design team produced the requisite specification in October 2018, and work began soon afterwards. The whole scheme was completed on schedule the following year.

The project succeeded in its aim of breathing new life and energy into the iconic building. It soon became a popular social venue and its residential units attracted consistently strong demand. The impressive thermal properties of the building helped to minimise occupants’ energy bills, and the whole development retained a bright, attractive appearance.

In 2021, the scheme was named as a finalist in the Insider Midlands Residential Property Awards, in which it went on to win the title of Apartment Development of the Year.

Project
Retrofit Conversion / Residential Multi-Storey
Client
Monk Estates & Harmony Bridge Ltd.
Specifier
Leonard Design Architects
Substrate
Cement Particle Board on Light Gauge Steel Frame
System
Permarock Mineral Fibre External Wall Insulation
Finish
Permarock SiliconeUltra K Finish