In February 2023, BHC appointed us as the architectural metalwork contractor for a building in Marylebone, London W1. BHC is the main contractor refurbishing the building, and this is a very prestigious project. LSJ Engineering was awarded the contract based on reputation, rather than cost alone, as we’ve worked with BHC on similar projects.
- Client: BHC
- Job date: February 2023 – present
The works were split into several different areas, from spiral staircases and Juliette railings to external lightwells and intricate service gates.
Part One: Juliette railings, a spiral staircase and a stair balustrade
Our brief was for a new build mews office space behind the main existing building. The new build is constructed entirely from CLT, a relatively new timber product that’s becoming more commonly used in construction.
We constructed Juliette railings for all three upper levels of the mews. The railings were set in front of the large opening sliding windows, fixed to the CLT structure with first fix brackets. This ensured that both the glazed brick face finishes and powder coated facia trimmings could be fitted before the main railings were fixed into place. The finished effect is fantastic:
This spiral staircase allowed access to a mezzanine level from the third floor. We built it in our workshop for accuracy, then disassembled it for reassembly on site:
The final part of this phase of the project was the steel balustrade for the staircase to the office building. We designed this balustrade as a dummy steel stringer, with the balusters welded to a secretly fixed steel plate. This ensured no welds or fixings were visible once the balustrade was fitted to the timber staircase – except for the main side fixings which were later filled and painted over. The final staircase has a lovely wood-and-steel finish:
Part Two: Four external lightwells on the existing building
The second phase of this project was refurbishing four existing external lightwells to the existing building. Also known as sky-wells, lightwells allow light and air to reach otherwise dark or badly ventilated basement spaces. These spaces are an excellent opportunity for architectural metalwork, because they usually require railings or similar safety features.
We designed and constructed hoop type balustrades and gates to form the guard rails. These balustrades had a traditional ‘London look’ and three lightwells included a feature access stair, running from the external pavement to the basement offices.
The access stairs were highly visible from the basement offices and required a minimal design to allow natural light through. This design meant the stairs had to be as slender as possible, with open grating treads. Part of the construction process is to ensure stairs pass crucial natural frequency design (wobble) checks, so we welded the stairs as a complete structure to minimise ‘wobble’.
Unfortunately, welding a complete stair complicated the final finishing (by Polytech Powder Coaters) due to their sheer size and weight. It also complicated the installation process. We’re never deterred by a challenge, though! We fabricated a special frame to allow the whole structure to be more easily taken into, and back out of, the powder coater’s oven. Once finished, we transported the stairs to site on a lorry supplied by KE Kent Transport of Basildon. We lifted them directly into place – with only two inches of room to spare – using the HIAB crane and a very skilled crane operator.
Here are the finished lightwells and stairs:
Part Three: Matching 1930s Juliette balcony rails to the main building
The third phase was matching some 1930s-made Juliette balcony rails to the main building. The balcony rails were quite complicated, as they are a hoop design with vertical bars and spheres.
We used an existing railing which had been removed to form a temporary access, taking it back to our Shoeburyness workshop to measure and copy the components. We used those measurements to fabricate close copies for three new first floor openings:
Part Four: Gates to the service yard
The fourth, ongoing, part of this project are two pairs of gates to the service yard area between the main building and the mews office building.
Although these are the gates to the rear of the main building, they will be one of its main features. They’ve been labelled Public Art gates by architects Fletcher Priest, and their design is critical to the planning approval process.
These gates are formed mainly of vertical four inch by three quarter inch flat bars. The top flat bars are rolled into concentric arches, with the two gate leaves overlapping as they close. While the design is wonderful, we encountered a logistical hitch. Because the gates require so much material, if we made them from mild steel (as originally intended), each leaf would have weighed over 900 kilograms… as you can imagine, this would cause issues with opening and closing the gates.
Our solution was to use aluminium instead of mild steel, in order to reduce the gates’ weight by over sixty percent. Using aluminium threw up extra challenges with fabrication, but the overall effect was a far better, ‘sharper edged’ product than mild steel would be:
Each flat bar will be painted a different colour to the two main faces. There will be yet another colour on the small faces. This entails three different painting and masking operations to each gate, which will take over six weeks to complete after we finish the fabrication process. This will look fabulous when complete.
We’ll share the finished gates in part two!
Are you interested in commissioning architectural steel work or steel staircases from LSJ Engineering?
We’re available for commercial steel work and staircase construction. Contact our team here, email info@lsjeng.co.uk or phone us on 01702 290 585. You can read about our other architectural steel work here and our steel staircase work here. We look forward to hearing from you!