An AT webinar, supported by SIG Design & Technology, explored approaches to detailing, and the relationship of the detail to the wider architectural concept

Successful details are essential not only to the performance of a building, but also to the communication of its architectural concept or parti. An Architecture Today webinar, supported by SIG Design & Technology, explored the profession’s enduring fascination with working details and how they can be used to shape and inform architectural projects. The event was chaired by Wayne Head, director of Curl la Tourelle Head Architecture, whose latest collection of booklets ‘DETAILS VOL. 8 New Towns’ is due to be published in Spring 2021.

In association with


Webinar participants

Amin Taha
Mary Duggan
Director, Mary Duggan Architects
Daniel Bosworth
Technical and Design Manager, SIG Design & Technology
Terry Fearfield
Technical Manager, SIGA Slate
Sasha Bhavan
Senior Partner, Knox Bhavan
Wayne Head
Director, Curl la Tourelle Head Architecture


Barrett’s Grove, London, by GROUPWORK (ph: Tim Soar)

Material narratives
Amin Taha began the event by exploring two idiosyncratic residential projects in London: Barrett’s Grove and Upper Street. For the former, the practice set itself a difficult challenge: ‘how to lighten the building’s superstructure and make the envelope self-supporting?’ The solution was to combine an independent load-bearing brick facade or ‘overcoat’ with a high-performance, lightweight CLT superstructure. Further material, cost and time savings have resulted from the use of self-finished internal timber walls and ceilings. Taha also made reference to shadow gap details used between the apartments and common parts to mitigate sound transmission.

Detail section through the facade of Barrett’s Grove by GROUPWORK

Won in competition, Upper Street completes a historic residential and commercial building with a striking terracotta-coloured in-situ load-bearing concrete structure. Explaining the concept Taha said, “The material and detailing choices tell the story of flawed monuments to the past, selective memory and misremembering.” Cast using 300 expanded polystyrene panels, the concrete superstructure incorporates pediments, pilasters, cornices, and even the imprints of anaglypta wallpaper internally.


Upper Street, London, by GROUPWORK (ph: Tim Soar)

Exploration through model making
Mary Duggan explored the connection between materiality and model making. “The way in which we communicate our conceptual ideas to clients is always via a singular piece or model – usually hand sized so it can be passed around,” explained the architect. “It becomes a reference point for the whole project.” Duggan presented a range of schemes, both built and unbuilt, through their concept models. In several, richly textured aggregate forms had been sanded down in specific places to signal ideas about construction, patination and materiality.

Wayne Head’s latest collection of booklets ‘DETAILS VOL. 8 New Towns’ is due to be published in Spring 2021

One of the most powerful projects shown was the design for a Dorothea Lange exhibition in London. The spaces subtly evoked the photographer’s awakening social conscience and most important work (documenting the Great Depression) by gradually ‘dematerialising’ to show exposed timber studs, frugal plasterwork and stripped-out skirting boards.


Lowfield Green residential development in York (image used with kind permission of City of York Council and @ShapeHomeYork)

Combining design and delivery
Dan Bosworth’s presentation provided a comprehensive demonstration of robust detailing solutions across a range of different roofs employed on a major residential project in York. Due to complete next year, Lowfield Green was originally specified with cold-applied liquid roofing for many of the flat roof areas, including the balconies and parapets.


Detail section through gutter at Lowfield Green (SIG)

Bosworth showed how SIG Design & Technology, in partnership with the main contactor Wates, was able to provide enhanced buildability, durability and cost-effectiveness by using a ‘suite’ of compatible systems and products. These include SIGnature Torch-on Bituminous membrane flat roofs and balconies, IKO Armourflow concealed gutters between elZinc Rainbow Red zinc roofs and IKO Armourplan single ply flat roof areas, as well as IKO PermaTec Hot Melt pitch-pocket details on the balconies to ensure fully encapsulated balustrade bases.


Lowfield Green balustrade detail (SIG)

“Compatibility between our products means that SIG is able to supply reliable, high-performance multi-product roofing solutions,” explained Bosworth. “Our approach is to provide the right product(s), good design, correct installation and reliable guarantees that reduce risk.”


SIGA Slate roofs at Ensleigh Gardens in Bath

Practical lessons for slate roofs
Terry Fearfield talked about detailing low-pitch natural slate roofs. Using a new-build housing project in Bath as a case study, he explained the importance of geographic location when it comes to specifying the size of slates and headlaps needed to achieve low-pitch roofs of 30 degrees or less. By increasing the headlap size and eschewing traditional nail fixings in favour of ‘blank’ slates with hook fixings, SIGA Slate and the project team were able to reduce the roof pitch by five degrees while retaining the desired 500x250mm format slates throughout the development.

SIGA Slate installation

Other design considerations highlighted by Fearfield included rafter lengths in relation to roof pitch, valley and hip details, establishing the correct fascia board height, and the need for additional roof ventilation.

Knox Bhavan’s London office (ph: Dennis Gilbert)

Making space for beauty and delight
For Sasha Bhavan’s practice, form and construction are inseperable from the outset of every design project. “Good detailing is important for reasons of weathering, but there should also be an element of beauty and delight,” said the architect. Craft is equally important, with the practice choosing to learn from, work with, and champion ‘makers’ of all kinds.

Exploded axonometric of lightweight mezzanine floor at Knox Bhavan’s London office

Central to the success of this approach is giving craftspeople a ‘good road map’ from which to work explained Bhavan. The practice takes pride in producing beautiful details that are drawn at large scale with every dimension and annotation clearly shown. “This is how you get something made with a high degree of precision out of fairly mundane materials,” she said.