An innovative building concept using composite floors and light steel framing was demonstrated in this Thames-side residential building, in which there was a requirement for light weight and creation of open plan space.

Structural engineer turned developer, Bryn Bird, wished to demonstrate his concept of a lightweight composite flooring system, developed with colleague Bernard Sanders, and turned to Metsec to realise his ideas. Tunnel Wharf in Rotherhithe, East London is the site of Bird's mixed commercial and residential development, which was made technically more demanding by the adjacent tidal Thames and Brunel's 1840's railway tunnel beneath.

The 8-storey building comprises 11 apartments and a penthouse in which the Bird family will live. The ground floor is for offices and possibly a restaurant, and below is a half basement car park. The high quality apartments range from 100 to 220 m2 floor area in 2, 3 and 4 bed configurations. 

 

There was a requirement for a lightweight structure to reduce the loads on the foundations, yet the super-structure was supported on a concrete transfer slab. The walls comprised pre-fabricated load-bearing panels from the Metframe system, with intermediate hot rolled system, with intermediate hot rolled steel beams and columns.

The innovative flooring system, Conform, used standard Metsec joists with a concrete topping supported by thin steel ‘pans'. The advantage of this system proved to be a lightweight structure, but with floors having sufficient mass to achieve excellent acoustic insulation and robustness to impact. Spans of 6.5 m were achieved with a single temporary prop, or 5 m when unpropped.

This gave the  partments a light, airy feel and, internally, the individual rooms could be easily fitted-out.

The complex curved walls and raking façades stretched the innovative design concept to the limit for this £3 million riverside development, but the end result is a lightweight building with open, adaptable space. It is one of the largest buildings constructed using Metframe and extends the use of light steel framing into medium-rise apartments.

Construction details

The Metframe system consists of 150 mm C section wall studs pre-fabricated into storey high panels. he steel thickness varies from 1.6 mm at the upper floors to 3.2 mm at the heavily loaded ground floors. he ‘Conform' flooring system comprises 185 mm C section joists supporting a 120 mm deep steel ‘pan' laced on the bottom flange of the joists. This ‘pan' acted as permanent formwork to the thin concrete opping above it. The overall slab depth was 220 mm. Reinforcing bars were placed parallel to the joists to rovide the necessary additional load resistance and fire resistance. Spans of up to 7.2 m were achieved in a rototype construction built before the project started. This project is the first example of this innovative looring system. Metframe uses the steel detailing package, Strucad, to draw, detail and fabricate the super-structure, which also ses the steel detailing package, Strucad, to draw, detail and fabricate the super-structure, which also  included many hot rolled steel components. The raking façade on one side of the building proved to be emanding, as did the 2-storey penthouse with its curved infill panels.

Reduces the steel detailing package, Strucad, to draw, detail and fabricate the super-structure, which also  included many hot rolled steel components. The raking façade on one side of the building proved to be emanding, as did the 2-storey penthouse with its curved infill panels.

External steelwork supported 4 or 5-storeys of brickwork on the south and east façades, allowing the ground loor to be fitted-out for commercial use. Elsewhere, zinc cladding was fixed to timber and was supported irectly by the wall panels by screwing through the Celotex insulation. Steel stairs were also supplied by etsec, which facilitated early fit-out.

The floor and wall structures achieved excellent acoustic insulation, higher than the standard of the Building egulations. A raised floor permitted service pipes and cables to be located on the floor slab, minimising holes through the slab.

The cost breakdown for this project is consistent with the complex nature of the site and the high quality of the building.

Summary

Architect	CZWG Architects
Engineering Company	Alan Consibee
Structural Engineer	Alan Consibee
Services Engineer	Max Fordham
Constructor	Ellmer Construction
Light Steel Framing	Metsec Framing
City	East London
Country	UK
Region	Europe
Climatic Condition	Temperate
Housing Type	Multi-family high rise

Key information

Number of storeys	8
Apartments	11
New-build home

    Quality Apartments using New Metframe Flooring System