The visible future

Conversions from office to residential under Permitted Development Rights are becoming more commonplace as we move to widespread home working. Structura UK’s Manny Patel looks at the implications for facades

Life has changed radically under Covid-19. The epidemic is changing the way buildings are used. One of the most obvious changes has been the lockdown and the enforced ‘working from home’ policy. Many companies have now realised their workers are as productive and as committed when working from home as when commuting to an office. This has led to a fundamental shift in policy, with many companies moving away from large expensive offices to smaller sites with ‘hot desking’ for meetings. This has led to a happier workforce not having to commute, and so much time saved.

With the move to smaller offices and companies seeking more self-contained buildings, the traditional large office block is suffering big dents in demand. This started before the pandemic, but the impact of Covid-19 has accelerated the trend. In 2018/2019 for example, 51 per cent of all new homes in Harlow were office conversions, and the CBRE are now reporting even larger swings.

The conversion of old offices to residential is nothing new, but the update to Permitted Development Rights in August last year means that now you don’t necessarily need planning permission so long as certain obligations are met. Some of the key requirements revolve around quality, location, size and light – i.e. have light and ventilation standards been adhered to? In the post-Grenfell world, standards are also important given the different regulations around products and fire ratings.

Many projects have illustrated how different disciplines can collaborate to provide a one-stop-shop for the complete renewal of facades. The ability to design, fabricate and install replacement glazing, along with cladding refurbishment and refinishing, can create a seamless project management workflow, and reduces costs and time spent on site. Importantly, it negates the need to use several different contractors with the associated problems that can entail.

Changing curtain walling on existing buildings is not always easy, yet can be critical when it comes to adapting older buildings. This can be to take advantage of improved energy efficient glass, for repairs or remedials or to make the buildings more suitable for residential conversion. It is also important in terms of newer building regulations around wind loads and fire resistance.

Fortunately, there is a precedent when companies have earlier vacated their own office building, in such cases much can be learnt about how the envelope was changed. A good example is Delta Point, the 28,500 m² former BT office building in Croydon whose entire facade was refurbished and refinished. This complete overhaul saw the building transformed into 404 apartments and other units.

Specialist preparation, spraying, venting and curing facilities were set up so the refurbishment could continue with minimum disruption. Work on panels was also carried out in situ from cradles suspended around the building. An added complication was the fact that, with the building changing use from commercial to residential, the paint needed to achieve Class 0 on spread of flame in accordance with BS 476.

Cladding innovation
Obviously, the character of glass and the design of curtain walling will change in the future. As Dr Ronan Daly, head of FIAM and senior lecturer at the University of Cambridge, is quoted as saying “Smart technology applied to glass has the potential to perform a number of important tasks – from identifying the presence of bacteria on a hospital window to performing as a touchscreen display.”

“Conductive materials can already be printed onto flat surfaces, and alongside the NSG Group we’re now overcoming the physical challenge of completing this for curved applications – this opens up new opportunities for designers to use glass technology to solve their modern design challenges.”

Historically traditional glazing has been the key to admitting daylight into a building be it residential, commercial or leisure. However, in other situations, translucent cladding holds the key. These allow for light transmittance but also offer quite different, and enhanced, material and performance benefits.

An example is Kalwall, an insulating cladding system developed in the US to transmit ‘museum quality,’ diffused light evenly into an interior without the harsh contrasts of light and shade. Avoiding hotspots, glare or shadows, it can remove the need for any blinds or shutters, while reducing solar gain and reliance on HVAC systems and artificial lighting. U-values as low as 0.28W/m²K, equivalent to a cavity-filled solid wall, are achievable by including translucent silica aerogel within the panels.

The recent redevelopment of the food court at Kings Mall Shopping centre, on a five-acre site in Hammersmith, London, highlighted some interesting and complex challenges. The new residential apartments above the shopping centre were being adversely affected by light pollution and lack of privacy from visitors walking through the food court atrium.

Owners and developers Schroders decided to install the translucent cladding around the whole of the atrium. This screened the external courtyard above, thereby mitigating the issues around privacy, while maintaining the maximum levels of interior daylight. The panels complement the industrial feel of the redevelopment and its hard concrete and stone surfaces, while providing benefits for shoppers and residents alike. These include line-of-sight protection, maintaining privacy for the residents and controlling light pollution, while bathing the interior with diffused daylighting, year-round.

So, as the urban landscape continues to evolve around us and the working patterns of millions of employees fundamentally changes, architects and designers have many innovative and forward-thinking companies offering the very best solutions in modern materials.

Manny Patel is managing director of Structura UK