Each detail in a Facit Home is carefully considered and none more so than the 6.8m tall stairway recently installed in Pocketsdell House.
The impressive laser cut staircase at the heart of this eco home was designed, manufactured and installed by Facit Homes. Our in-house design and engineering expertise always extends to the entire home with intricate interior features as part of our turnkey service.
Our customers, Patrick and Scott (with their dogs, Barley and Fin), wanted a home that reflected their love for nature - something evident in their extensive plant collection, design for a wild swimming pond and choice to incorporate bat boxes in their home. Building their own home meant they could design a property that suited the way they want to live as well as benefit the local biodiversity.
As a central element in their new home, the staircase is a key part of their interior design and spans the three floors of the home. We proposed an intricate, laser cut steel design for this space.
Building regulations informed part of the early design discussions. The required balustrade height of 90cm to 1.10m would have meant that a rail ascended from the floor below into an angular point in the centre of their open plan living room.
So, the team worked to design an enclosed staircase that rotated at 90 degrees onto itself in a spiralling, trapezoidal shape.
Perfecting the pattern
The design for the shell of the staircase consisted of long parallel panels that were to stretch from the basement to the first floor, creating a sensation of flow between the floors. The pattern of the laser cut steel would define the amount of light on the stairs and in the room.
Starting as an open staircase with balustrades (see below), the design moved to solid panels that spiralled between the floors for structural advantage. The design chosen was an abstract pattern with slim borders and laser cut shapes to allow natural light.
Designed after the cor-ten tree columns that feature on this home, we were able to match the aesthetic of the staircase to the structural steel nature of the tree columns.
The final design was inspired by an image found by Patrick and Scott which showed a pattern replicating the appearance of cells in a leaf as seen under a magnifying glass - bringing nature into this structural element. It consists of three cell-like, circular shapes.
The eagle eyed among you may be able to spot a few of the shapes recurring in similar positions - this is because the pattern was designed to be tileable. Creating a repeated 50x50cm square of the design optimised it for manufacturing.
In order to create a more natural feel, the edges of any “cells” that were cut into by the required borders were rounded out in unique shapes. This detailing allowed us to remove the rigid lines between the pattern and the panel borders.
Folds in the steel (most visible as solid black lines in the image above) create strength in the material and incorporate a linear aesthetic between the panels. The folds are visible from the exterior of the staircase but not from the enclosed and entirely smooth interior. The slim borders around the pattern allowed the folding to take place without disruption to the design - and matched what was required for manufacturing and assembly.
Manufacturing the staircase
First, there are a few industry terms that might help.
Design for manufacture (DFM; not a catchy term) is the engineering practice of designing products so that they are simpler to manufacture - creating a better product by combining the knowledge and experience of manufacturing with the act of design. It involves consideration of every part from the length of screws to material dimensions and the fixings that hold parts together. For anyone familiar with flatpack furniture, Ikea are the masters of DFM.
This will seem like common sense but the reality is that many designers think about manufacturing or fabrication afterwards (which can lead to redesigns and escalating costs). The Facit Homes approach to digitising construction meant that despite having never built a staircase structure like this one we could still create this design.
CAD, computer aided design, is an overarching term for the use of computers in the creation or optimisation of a design. BIM, building information modelling, which we use to design every element of our homes is a process that results in the generation and management of digital representations of physical characteristics. BIM is the process of creating and managing a ‘digital twin’ - an exact replica of a physical product that can ensure the design is accurate.
Once we had created the digital design within our BIM software, work began to assemble the production information for the manufacturers. This included instructions for cutting and folding large sheets of steel, such as below.
We tested the feasibility of our design with an installation run-through of the longest panel. An essential step in designing something new, it was important for us to check that the team on site were happy with the method of installation as well as whether the material would behave as predicted.
One of the team on site even stood on a single sheet to prove its tensile strength.
Once we had proved it would work, we supplied the final technical design models and our fabrication partner Lasershape converted our BIM specifications into G code - the computer language that gives the machine instructions for laser cutting the intricate pattern in the panels of steel.
Installation was a complicated process that involved the careful coordination of material delivery and support for the team on site. We ran into a few delivery issues over the Christmas period, which set back completion by a few weeks.
The panels were delivered to site ready for installation, but some required welding into place around the three large PFC steel beams in the centre of the staircase. These columns are the incredible strength at the heart of this impressive steel staircase. Each one weighs an impressive 150kg. We’re not kidding! You can imagine the team strength it took to manoeuvre those into place on site.
The design of the treads (the steps) evolved from solid timber (which would have increased the weight and cost) to raw steel. We recognised that the structure would be quite dark so added LED lights under the handrail to illuminate the interior and further increase the shadows cast by the pattern.
The final step in the construction process was to polish the steel. After being moved around on a very muddy site (always in order so that the first panel required would be at the top of the pile) the panels and treads needed to be cleaned and protected against rust and to get the beauty of the steel to its very best.
And finally, the socks-on-the-stair test. Result! Not slippery.
A studio collaboration
As you might expect, this staircase required the expertise of more than one in the Facit team. Nick (Design Engineer), Fanis (Lead Architect) and Bruce (Founder) worked with our customers to define the very early concept designs based on the space available.
Nick then worked closely with Patrick and Scott to create the beautifully detailed design. As he said, “we managed to find the perfect middle ground between what the building needed to comply with regulations and what the customers wanted for the design of their home.”
Also responsible for creating production information for his intricate design, Nick worked through all the dimensions, practicalities and logistics of the manufacturing and installation - a lengthy and detailed process.
Credit is also due to Ryan, Ale and Jonathan for their work coordinating the site operations, including the storage and assembly of the staircase, working with the manufacturers for delivery and ensuring the right people were on site at the right time (with the right tools).
For more information about this project, visit Pocketsdell House.