FCBS goes back to the Energy Efficient Office of the Future
In 1996 Feilden Clegg Bradley Studios (FCBS) designed a landmark building at the heart of the BRE campus near Watford, providing 1,350m2 of office space plus seminar facilities showcasing energy-efficient environmental design, particularly innovative for the 90s. Building 16 received a BREEAM ‘Excellent’ rating, the highest score recorded at the time.
The specification, devised as part of the Building Research Establishment’s own Energy Efficient Office of the Future project, set stringent targets for energy consumption and addressed wider concerns, such as recycling. Some 96 per cent of the material from the demolition of redundant workshops on the site was recycled into the building and this was the first use in the UK of recycled aggregate for the concrete superstructure. Other recycled material included brickwork, screeds, gypsum recovered from a power station and wood block floors from County Hall in London.
Nearly 30 years later, FCBS has returned to the project, along with Building 17, a late 70s office block also on the campus, refurbishing them both to create 2,800m2 of rental space and 1,100m2 offices for BRE employees. The AJ buildings team spoke to FCBS associate Ron Nkomba about the practice’s experience of retrofitting a building it once designed.
How did FCBS come to be undertaking this project?
It was won through a mini-competition let through the NHS Shared Business Services Framework, which we entered because it was an opportunity to revisit a building we had completed in 1996, together with another building. BRE had secured £2.2 million of funding from the Hertfordshire Local Enterprise Partnership to create an open innovation hub to support a cluster of local businesses, enabling them to lease office space at BRE to be closer to the research expertise there.
This coincided with the onset of the Covid pandemic, so BRE decided to invest additional funding of £1.1 million to refurbish part of the buildings as their own offices, focusing on future working trends as well as a low-carbon approach to office refurb. All these factors made it a really interesting brief.
How did you approach the two buildings in view of their ages and one being to your own design? Did this affect your strategy?
We initially looked at four buildings on the estate, ranging in age from the 1950s to our own building from 1996. The two buildings we highlighted for the initial phase of refurbishment – BRE is looking to refurbish the other two in the next few years – did present different design and refurbishment challenges.
So, yes, we approached them with different strategies. Building 16, our 1996 building, needed a lighter touch, while Building 17 – BRE’s main administration building from the 1970s – required more internal reconfiguration.
The overall challenge was that, although the two buildings originated in different decades, BRE wanted the two spaces to have a common legibility, operational approach, spatial aesthetic and palette of materials.
Had anybody on the project been part of the original team in 1996?
Peter Clegg had been involved with the original design and was involved initially as a champion for that but most of the team were looking at it with fresh eyes.
Did this help you not to be too precious with the original building?
I think so. Probably being slightly distanced from it, not having been involved, yet still knowing it was an FCBS building, did allow us to not become too precious about some of the things we were doing. Also, in the period since its completion, there had been a few internal modifications, done by BRE. So when we looked at the strategies that we wanted to follow though, some did hark back to what we’d originally done in 1996.
How were the buildings failing or not performing? What needed to be fixed?
Building 16 had aged pretty well in terms of providing flexible office floorplates. We opened up some cellular office space on the ground floor to make it more lettable for the innovation hub. The subsequent refurbishment was relatively light-touch: upgrading lighting, looking at some operational issues, replacing floor finishes and giving it a light refresh throughout.
Building 17 required more of a physical reconfiguration strategy. Much of the existing office space was cellular and therefore not flexible nor compatible with the contemporary workplace. Orientation and navigation were unclear, with little opportunity to encourage interaction or collaboration. There were significant operational issues too for heating and lighting systems. The low ceilings and deep plan of some floorplates made a lot of the spaces feel dark and uninviting.
BRE wanted to produce an exemplar for low-cost, low-carbon refurbishment: can you explain your general strategy for this and the balance between upgrade, refurbishment and recycling?
Our initial approach was for a fabric-first strategy to upgrade building envelopes and increase operational carbon efficiency. Unfortunately, quite early on it became clear the budget wasn’t sufficient to fund major works to external envelopes and so we knew we were dealing predominantly with internal refurbishment, service upgrades and trying to maximise what we could do internally.
We started by looking at reducing operational carbon over the two buildings. We undertook a complete refurbishment of the heating systems to make those more efficient, reinstated the natural ventilation strategies that had been inherent in the original designs by refurbishing window controls and actuators, installing blinds to deal with glare and overheating, and upgraded lighting across both buildings from fluorescent to LED.
We also reconfigured or refurbished the existing WCs and tea points with low-fluoride sanitaryware. In Building 17 we removed a lot of the ceilings to expose the thermal mass of the concrete floor slabs, which contributed to improving the thermal comfort and feel.
We then looked at reconfiguring the spaces, implementing a simple waste elimination hierarchy – reduce, re-use, recycle – before looking at a low-carbon spec for new items. An early pre-demolition audit was undertaken, in which we identified all the items we thought could be re-used: some internal doors, carpet and ceiling tiles, lighting, fixture housings and timber studwork from partitions.
We also focused on the refurbishment and re-use of existing furniture. We then defined which items were fit for purpose or what form of restoration would be required to enable their re-use.
When specifying new items (flooring, glazed screens) we worked with suppliers to identify the lowest embodied carbon certification possible, targeting carbon-neutral or cradle-to-gate.
So you were able to re-use elements such as carpet tiles?
We didn’t use as much as we would have liked but, interestingly, because the office layout hadn’t been changed for a long time, we identified that carpet tiles under desks were in an almost new condition. We were able to reclaim these for use in some of the more public circulation areas, where the tiles were heavily worn.
There were practical issues, such as the fading of colours over time. Taking bits from different areas and combining them made the differences visible. We found it was possible to re-use carpet if you deploy it in larger batches. That was one of the learning curves.
Rotor Deconstruction in Belgium uses material passports and categorises its components and materials when it takes buildings apart. Did you do the same?
We did, but in quite an analogue way. Material passports and QR-coding elements are really great ideas but on site, when you ask the contractor to take down a load of ceiling tiles, for example, some of them get damaged. We did it in more of a visual condition, fit-for-purpose-based way. We asked the contractors to reclaim as much as they could. This was then stored in an unused part of the building, where we were able to go through it and identify which elements were re-usable. For instance 1,200 600 x 600mm ceiling tiles were taken down but only 800 of them were fit for purpose to be re-used in ceiling rafts.
So, while QR-coding or digitally tagging items is a great idea, a lot of time could be wasted tagging items that aren’t able to be re-used, so perhaps that process should happen after the demolition phase, once you want to reimplement those materials.
How extensive was the post-occupancy data for the buildings?
There was some basic energy performance data for both buildings, as BRE monitors its own energy consumption. This was a useful starting point for looking at reducing operational carbon and highlighting where the issues were – such as heating systems. We started the project almost a year into the pandemic, so both buildings were empty. We therefore had limited ability to question occupants about how the building was failing, so this was more anecdotal. But BRE had compiled a really useful survey of employees covering environmental and comfort control shortfalls in each building: predominantly issues with glare, heating and ventilation.
How much did this help to identify what the priorities were for the refurbishment, compared with visually assessing or surveying the building’s physical condition?
Their survey was definitely useful in identifying refurbishment priorities, adding a further layer to our visual assessment.
Some of the priorities were really simple. Both buildings are naturally ventilated and have pretty good passive ventilation strategies. In our own 1996 building the stacked ventilation chimneys and the cross-ventilation through the slab still worked well. But in the 70s building, natural cross-ventilation was hindered by the cellular nature of the space, so the priority was to reduce glare and overheating.
We started looking at internal blinds to reflect heat back out and at making these work in conjunction with window openings. For instance, in Building 17 you have traditional lower casement and upper casement openings. In summer you open the lower casement to get a breeze through and cross-ventilate the building and then in winter you close that and open the upper casement to avoid cold draughts but still get ventilation. But we discovered many occupants didn’t know how to use these.
So we reinstated those ventilation principles, installed blinds so they wouldn’t interrupt airflows but would deal with the heat and glare, and then rebranded and designed a whole signage strategy – including simple signage on each window reveal informing people how to operate the windows. It’s really important, as sometimes a lot of the issues with buildings is due to building occupants not knowing how to best utilise them. We’re hoping that a simple sign telling you when to put down the blind or to open an upper or lower window will bring a layer of user control and improve these issues.
Did you have a target figure for reduction of annual operational carbon emissions?
We were tasked with defining where operational carbon reductions could be made. We then needed to set a target as part of the Hertfordshire Local Enterprise funding on both embodied and operational carbon reductions. These were set at RIBA Stage 3 as part of the requirements.
For the operational carbon, reductions came predominantly from upgrading the heating systems and switching from fluorescent lighting to LED across the two buildings. And we managed to re-use a lot of the original light casings, stopping them going to landfill.
Were you working to a per-metre budget?
During the original cost plans it started coming out that we were working to a tight £850/m2 budget. As a benchmark, our cost consultants said that for a Category A fit-out we would be looking at between £1,000-1,500/m2. It was challenging. The way we worked through it was by updating the cost plan periodically and at the end of each RIBA design stage. That helped prioritise items we wanted to re-use and refurbish.
The furniture, fixtures and equipment budget in particular was really challenging, so it was a given that re-using existing furniture where possible was a priority. Similarly with the ceiling tiles. There was no defined budget for acoustics, so when developing our strategy to meet the requirements for the office space in terms of reverberation time and clarity of speech we realised we needed to re-use existing tiles, reconfigure these into acoustic rafts and deal with the acoustics like that. So, in some ways, the cost constraints helped drive and prioritise sustainability agendas.
Can you briefly outline how you refurbished the furniture?
The office work desks were mainly from the 1980s. While the steel legs were in a really good condition, the tops were L-shaped and didn’t allow for more contemporary working. So we reclaimed all the legs and then re-topped the desks so they were more flexible to use and could integrate data and power for computers. The existing office chairs had a whole range of different design styles and fabrics. Working together with our furniture supplier, JPA, we identified which chairs could be refurbished back to working condition.
Then we put in place a strategy that co-ordinated with BRE’s new branding to determine a colour palette range within which the chairs could be refurbished. Once re-upholstered with a range of fabrics in a coherent colour palette, the fact that all the chairs are slightly different didn’t matter: they hang together quite coherently.
How did you look to maintain the spirit of the original when upgrading and changing the building fabric?
We took a steer from the original building and it was really the passive design elements that we took from it. Also the provision of flexible open plan office floorplates, looking to enhance natural daylight and shading against glare.
We took a big steer, too, from the original palette of materials of our 1996 building. The warm, natural materials and colour tones we used informed our new palette across both buildings, helping to unify the spaces and to promote the feel of a healthy and sustainable workspace. We also promoted the latter by using the natural assets of the site, opening floorplates to reveal the wonderful views to nature.
How have changes in the way people work, both since 1996 and post-pandemic, affected your design strategy?
Between 1996 and the pandemic, the biggest change was probably the shift from cellular to open plan working.
But the pandemic presented a significant change. With the introduction of flexible and hybrid working, BRE was keen to focus on the collaborative side of working. We worked closely with them on furniture provision and layouts for each office floorplate to provide different workspace types and configurations, which, in effect, they’re testing to see which are more subscribed to or used.
These included individual traditional task-based desks in an open plan office setting, counter-height desks and chairs for group work and collaboration, more informal lounge-type workspaces for collaborative meetings, and acoustically separated booths for virtual meetings as well as traditional separate meeting rooms for more private team meetings. We also looked at hot desk opportunities on each office floor and in the café.
We were considering the different ways people might work. Virtual meetings can be quite challenging when people are coming to the office for a day and require a dedicated desk to sit at.
So we tried two different arrangements of furniture over the two floorplates. One has the workspace on one side of the floor plate and collaboration space on the other, while the other mixes traditional desk workspaces with collaboration space.
We also upgraded the wifi and internet systems to allow people to work anywhere in the building and extended that to the new first-floor café for those people who might come to the campus for just an hour’s meeting but want to sit there before or after.
It’s interesting. Staff are only now starting to completely return to the workplace and BRE is monitoring which of the workspaces is more used.
Our challenge was to pre-empt this by configuring services to give flexibility and allow for floorplates to be changed. It’s a strategy of setting out lighting, power and data so that everything is loose-fit, long-life – it can be rejigged over time.
What did you learn from upgrading a building designed by your practice nearly 30 years ago?
Looking at our own building, we realised that it has been adaptable and flexible enough to change with the times. It was designed to incorporate both open plan and cellular offices in terms of ventilation and lighting, as with many buildings we do.
I think we learnt that what we were doing 30 years ago was quite pioneering, in contrast with the 1970s building, which wasn’t as flexible. We implemented some of these very basic design principles across both buildings, knowing it’s impossible to predict how work patterns will change over the next 30 years.
However, if you get the basics right –flexibly serviced floorplates and aspects that promote health and wellbeing: good natural daylight, eliminating glare and overheating, an element of user control so that people are knowledgeable about their buildings and how to use them – then an office should be able to accommodate changing work patterns for years to come.
Was there anything about your original building (FCBS’s Building 16) that didn’t work?
Not really. I think the original design has held up well. Its more the things that were implemented over the first 10-15 years of its life – such as closing up some of the floorplates – that has made it slightly less flexible.
Has this led you to be more critical about the flexibility of other FCBS buildings?
It has made me more aware of how sometimes simple interventions have more power than a very complicated approach. It’s going back to those basic things that make people work in a better way or feel happy. The way that we come to work and interact with each other has completely changed. In effect people tend now to come to work to collaborate with each other, as opposed to sit and concentrate. We always try and build-in that flexibility, not only in our office buildings but in our school and higher education buildings: whether it’s closing up or opening space, deciding where core services, toilets, tea points are located, places where people can meet, the nature of staircases – all the elements that enhance our social engagement.
Looking back at the buildings I’ve worked on, they all had some of these elements. Realising how key these things are is important. We sometimes get too focused on the build-up of a glazing system or envelope – and, of course, these have to work to provide environmental comfort. But, once you’ve implemented this, the nature of the internal spaces and how they make people feel is probably one of the most important elements we’ve become aware of over the past 20 years.
Start on site July 2021 (enabling works), November 2021 (main refurb)
Completion May 2022
Gross internal floor area 3,900m2
Construction cost per m2 £850
Architect Feilden Clegg Bradley Studios
Client BRE Group
Structural engineer Alan Baxter
M&E consultant Cundall
Quantity surveyor Gardner & Theobald
Project manager STEAM
Principal designer Feilden Clegg Bradley Studios
CDM adviser CDRM
Approved building inspector Harwood
Main contractor Logan Construction
Access consultant Buro Happold
Acoustics consultant Cundall
BREEAM consultant Cundall
Fire consultant The Fire Surgery
Embodied carbon 186 kgCO2e/m2
Whole-life carbon 61 tonnes CO2e
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