12mx12w=100K

The perfect formula

12 months of design, 12 weeks of works on site, for around a 100k budget.

These are the numbers behind the refurbishment of a flat in a converted Pump House Station which I’ve just completed.

Small projects often rush into on-site work prematurely, with professionals presenting hurried design as efficiency, masking lack of imagination behind claims of common sense.

In contrast, with this project I have eventually proved a point: with a tight budget, the wisest thing is investing in time for design.

I always knew that time spent on design is inversely proportional to time wasted on site and, by consequence, to wasted money, but I had to wait 25+ years in this profession to get the opportunity to fully demonstrate my assumption.

I had to wait for the right location, the right project, the right client, the right team, and the right Contractor.

The building

The property is situated within the historic Pump House Hydraulic Station in Rotherhithe, which underwent conversion into residential units approximately 25 years ago. Classified as Grade II, this structure stands as a remarkable representation of late Victorian industrial architecture, with construction completed in 1902.

The flat in question is located within the "Gateway building," originally designated as the coal storage and characterized by its distinctive red-cast-iron water tank roof. Among five units within this structure, the flat's layout mirrors that of its counterpart, featuring an expansive open volume measuring 4 x 8 meters and 8 meters in height. The ground floor houses a combined kitchen and living area, while a mezzanine level overlooks this space and included a square bathroom, with a total area of approximately 50 square meters.

Distinctive architectural elements include a prominent arched glazed opening at the front of the flat and a smaller window at the rear, unfortunately not accessible as at 2.5 m from floor level.

Internally, with three sides featuring exposed brickwork and an adjacent plasterboard partition wall, the cast iron ceiling—originally the base of the water tank—stands as a notable feature, supported by three substantial girders spanning from the rear to the front of the flat.

Challenges such as non-existent storage space, outdated services and finishes, coupled with inadequate ventilation leading to issues of humidity and condensation, compounded the property's deficiencies. Additionally, the heating system's inefficiency—comprising only two radiators servicing a voluminous space—underscored the need for comprehensive renovation and improvement measures.

In short, not the ideal flat, but certainly a great potential to be unfolded.

The project

The project entailed several key enhancements, including the addition of an extra floor and bathroom, the reinstatement of a side window, adjustment of the rear window size to facilitate cross ventilation, and the optimization of storage space.

Rather than retaining the original open gallery layout, both upper-level rooms now feature enclosed spaces delineated by glazed partitions. Access to these rooms is facilitated by a network of bridges featuring perforated metal flooring, spanning the triple-height stairwell adjacent to the arched window.

To preserve the property's architectural and historical significance, particularly its Grade II listing, the second floor is affixed to the girders using clamps, eliminating the need for invasive drilling or welding. Endorsed by the Conservation Officer for its reversible nature, this method ensured compliance without compromising heritage significance.

Improvement in heating system optimization include relocating radiators to the upper-level rooms, minimizing heat loss by enclosing them with glazing. Additionally, a new underfloor heating system warms the open ground floor space efficiently, utilizing radiant heat to avoid energy wastage associated with heating large air volumes up to the cast iron ceiling.

The project effectively expanded the property's footprint by 60%, increasing from 50 to 80 square meters and augmenting storage capacity by approximately 15 cubic meters.

The Challenges

The most formidable obstacle encountered was achieving compliance with Building Regulations concerning fire safety. Introducing a second mezzanine level (effectively constituting a third floor including the ground level) triggered requirements for a comprehensive sprinkler or mist system throughout the property, along with the installation of a smoke ventilation system. Complicating matters further, the property's thick cast iron roof planks, designated as a listed feature, precluded the installation of an automatic venting system.

Several consultations with specialist and firms yielded nothing more than conventional, off-the-shelf solutions unsuitable for the project's unique requirements. Eventually I met the right professional (Bob Parkin at Marsden Fire Safety Ltd) who, armed with unparalleled first-hand experience from the Fire Brigade and an innovative mindset, pushed me to devise a tailored solution that not only mitigated fire risks but also positively influenced the project layout.

The room on the first level, originally intended as a passage area, has been enclosed and now offers direct access to the reinstated side opening, serving as an egress window. Similarly, the new room on the second level has been equipped with its own escape route, utilizing the resized rear window.

The solution necessitated the replacement of both the existing stair and the first-floor level structure, which were initially intended to remain in place. Nevertheless, full regulatory compliance was attained, eliminating the necessity for sprinklers or a mechanical smoke system. This ensured the preservation of budgetary balance alongside safety measures.

The teamwork

Each member of the team (including the client) exemplified a capacity for innovative thinking, a vital attribute given the distinctive circumstances surrounding the endeavour.

Collaboration with Structural Engineers ( George Ramsay Helder Matias - Structural Engineer - Data Science ) was instrumental. Besides ground-breaking solution of suspending the new upper floor from existing girders using clamps, embracing the vision of preserving and enhancing the original character of the space, the team of engineers embarked with me on a transformative endeavour, integrating floating bridges, exposed structural elements, and one of the most bizarre staircases I ever designed.

Utilizing BIM models from the project's inception fostered a dynamic and productive partnership, transcending mere cooperation to embody genuine synergy.

However, the most profound collaboration unfolded with the Contractor.

AG Italy was chosen in May 2023 due to their expertise in retail projects, which I interpreted as a testament to their ability to adhere to agreed timelines. Additionally, Gianluca's background in Civil Engineering from an Italian University instilled confidence in his methodical approach to work.

Notably, Gianluca - as Technical Manager for AG Italy - stood out among the Contractors I contacted. While others simply provided ballpark figures in response to my package containing drawings, 3D models, Virtual Tours, and a meticulously detailed Schedule of Works, Gianluca took the initiative to inquire, "May I add some detail here and there?" This proactive attitude instantly won my trust.

However, the initial estimates exceeded the budget, prompting immediate action. Through close collaboration, we revisited project details, materials, and finishes, achieving a 30% reduction in construction costs. Together, we streamlined solutions and details, aiming at simplifying on-site activities and optimizing the project timeline.

My philosophy is that a well-conceived design sets a robust framework which is strategic during the construction phase. However, rather than aiming to rigid adherence to initial plans, the goal was allowing flexibility during the execution, facilitating quick decision-making, accommodating adjustments seamlessly, and minimizing the necessity for costly rework.

Method

Although modest in scale, the entire project was meticulously managed through Building Information Modelling (BIM). Leveraging the power of a comprehensive 3D model, the team seamlessly coordinated the existing structure with crucial elements such as pipes, ductworks, and intricate joinery details.

This integrated approach, synchronized with the schedule of works and quantities, ensured precision and efficiency at every construction stage. Additionally, the on-site team had instant access to 3D models of individual components and junctions, easily navigable via smartphone through QR codes imprinted on plans.

The CGI Virtual Tour, generated directly from the BIM model, emerged as a pivotal tool in the project. Beyond providing the client with a user-friendly platform for comprehending finishes, materials, and spatial implications, it also proved invaluable to the contractor.

Engaged in realizing the envisioned outcome portrayed in the CGIs, the contractor embraced the challenge head-on. A comparison between the CGIs and the final photos unequivocally demonstrates the fulfilment of this challenge.

Outcome

It is time to reveal that the Client is my wife and the flat serves as our primary residence. This circumstance necessitated our absence throughout the entirety of the works, with the me undertaking weekly visits from abroad to oversee progress.

Consequently, the formulation of a time-effective program became imperative. Moreover, given that the project was funded solely by personal savings, strict adherence to the budget was paramount.

The objective of completing the project in accordance with the specified design, within the agreed 12 weeks’ timeframe, and without surpassing the allocated budget has been achieved with a perfect score of 100%.

The use of perforated metal catwalks, glazed floors, and strategic spatial planning now accentuates historically significant details such as the soaring 8-meter floor-to-ceiling volumes, the distinctive 5.3-meter arched front opening, and the intricate metal roof and beams. The reinstated side opening provides insight into the building's original functionality as a Pump Station.

Leveraging the industrial character of the building, cost-effective choices were made, introducing materials and finishes probably inappropriate in a different context, like plain concrete finishes, galvanized tube balustrades, and polycarbonate sheets.

Though comprehensive data analysis is ongoing, early indications suggest a notable reduction in energy consumption per square meter per year, anticipated to fall between 40 and 50%.

Beyond enhanced comfort—realized through one additional rooms and bathroom, increased storage capacity (+ 15 cubic meters), better use of the space at ground floor with a compact design of the main staircase, improved heating, lighting, and acoustic insulation — the project's success is also quantifiable in terms of Return on Investment (ROI). By expanding the footprint, modernizing components, and elevating comfort standards, keeping the budget under control, a ROI ranging between 2.4 and 3 is anticipated.

Conclusion

When my wife was discussing with colleagues and friends the timeline for completing our refurbishment works within 12 weeks, sceptics scoffed, prompting my wife to explain, "You see, the architect is my husband, and he meticulously organizes everything with the Contractor using spreadsheets." This revelation elicited surprise from others who admitted their contractors never adopted such organized methods...

Using spreadsheets reflects a mindset of planning, information sharing, and maintaining control—qualities often dismissed as unnecessary for domestic projects.

Recently, someone remarked to me, "In your world, 6 months equals a year", speaking of project duration. I responded that in my industry, perhaps, but in my personal world, 6 months unequivocally means 6 months. Full stop.

The formula 12mx12w=100K, written as 100K /12w =12m, underscores the importance of allocating more time for design when operating under a tight budget (100K) and short timeframe (12 weeks).

Prioritizing thorough planning over immediate commencement of works is the only way to ensure efficient utilization of resources and timely project completion.