by Anmol AhujaDec 11, 2021
Sourabh Gupta recounts his visit to the plush Lalit Mangar hotel campus, where he met Ashwin Alva, the architect whose vision for creating a rammed earth building complex, using earth sourced directly from the site itself, was finally realised after a decade long journey. Here, they discuss the evolution of the vision, design, engineering and technology that led to the fruition of this contextually relevant and climatically sustainable luxury resort.
As we juggled with dates to figure out our schedules to meet and visit The Lalit Mangar, I realised that recently, a rural Chinese house with rammed-earth walls was proclaimed the World Building of the Year 2017 at the World Architecture Festival in Berlin. This got me thinking - about the newfound interest, the validity and the beauty of this ancient material in our times. Despite being used for centuries even in the likes of the world’s wonders such as The Great Wall of China, coupled with the advantage of labour intensive constructions so prevalent in India, the need of using local materials, minimal equipment and thermal walls for sustainable architecture of our region, we are certainly losing out on our explorations in this direction. Why have we then limited our inquiry into the process and possibilities of this potent material?
These queries led to conversations, which further triggered the interaction with Ashwin Alva. The time spent in dialogue with him at the resort on an early winter afternoon brought together an understanding of him and his work; and a reflection of the directions and departures of architectural practices of our times.
THE JOURNEY OF THE LALIT: ALVA EXPLAINS
We decided to develop the design to be ‘of’ the earth it was located on, rather than ‘on’ it, using the soil itself as the primary construction material for rammed earth loadbearing walls. - Ashwin Alva
The Lalit, Mangar, a 40-room luxury getaway, Boutique Resort, located on a rocky-outcrop of the Aravalli Hills, amidst an untouched landscape, provides a counterpoint to the bustling metropolis of Delhi, just a half hour drive away. The site measures 15,300sqm, sloping down 10m along its 275m length, further dropping 30m into a ravine below. The property offers panoramic views, towards the valley on the south as it stretches from East to West.
Considering the sensitive nature of the surroundings, the absence of any built environment around and the hot semi-arid climatic conditions, it was imperative to be as ecologically sustainable in our design approach and create a built environment which would not just be sustainable in its performance and function but also in its mode of construction and resonate the same in its built form and finish.
We decided to develop the design to be ‘of’ the earth it was located on, rather than ‘on’ it, using the soil itself as the primary construction material for rammed earth loadbearing walls that rest upon a random rubble plinth made of brown quartzite as excavated from site, as the primary built form.
Analysing the soil strata, we explored multiple ways of using the soil as the primary construction material before narrowing down on Rammed Earth Construction, over a rubble plinth, out of the brown quartzite, as excavated from the site. The ‘North Block’ housed the back-of-house at grade, forming the rubble masonry plinth supporting the load-bearing rammed earth walls of the guest rooms above. The ‘South Block’ ran in parallel as single storey guest rooms built on grade.
Not content in just utilizing rammed earth as thermal mass, we focused on improving thermal performance by developing an insulated cavity between two 175mm whythes of rammed earth. The inner load bearing whythe supporting the roof provides the finished inner face, while the external skin becomes the façade of the building.
The continuous insulation envelope, with minimal thermal bridges, runs along the 220m length of the property. Wrapped over both the vertical and horizontal faces, it creates arguably the largest insulated rammed earth building in the world.
Challenges of construction included testing and engineering the rammed earth loadbearing whythe to a minimum 175mm thickness, as we wanted to restrict the overall construction wall thickness to avoid losing valuable floor area.
A critical design cue was for the masses to not just be monolithic but read monolithically. There is not a single formwork joint in the complete building. The formwork was developed as a repetitive module, which would slide forward and back and up and down in its individual components creating multiple permutations of guest suites. Each formwork module was 4.0m tall to ram the same in one go. Services too were integrated into the rammed skins and affixed inside the forms prior to ramming.
Lack of relevant codes and published norms led to the structures detailed with rebar to cater to stringent seismic norms of this zone, detailed in a way to permit ramming within and around the rebar cages. Mixing of soil was carried out with screw-type mixers to ensure consistent dry-mixes and constant testing was carried out to ensure compressive strengths of M25 as achieved. The consistency of strengths achieved emboldened us to ram the public area as framed structures. Rebar detailing was modified to allow for pouring and consolidated the mix by ramming against conventional wet mixes dependent on mechanical vibration. This is possibly the only framed rammed earth structure ever built.
Eliminating additional internal/external finishes has removed the need to refinish surfaces over time, resulting in a commercially viable design idiom. Incredibly, more than 80% of the raw material for its superstructure has come from the land itself!
The design was ordered around a series of courtyards, typical to the organic growth of Indian villages, cascading down the site, linking in and around clusters of rooms. All rooms face the south, which allows for better flexibility in thermal control and enhances the exposure to the winter sun. We faced many design and construction challenges, which when overcome, led to the execution of one of the largest insulated rammed earth structures, and the public area component, as the only framed rammed earth structure ever built.
Guests are intimately exposed to the rammed earth in every surface, inside and out, understand the sustainability of its construction and of its performance, and its suitability to the context of the resort. It gives them a greater appreciation of their surroundings and an enhanced understanding of how built forms need not be restricted to conventions of concrete, brick and glass.
There is no guest who leaves the property without learning about the uniqueness of its construction and appreciates its eminent suitability to the site and its function.
The spirit of the journey was clear in it is narration. This reasoning and the reality resonated with me as one dwelled deeper into the motivations and manifestations of a creative process that I was so aligned with. It made one pause and perceived one’s own work differently.
I wondered why this was not taken as a language that one’s own studio picked up as a useful tool that could be replicated; but the answer was in seeing the precision and the pain needed to pull this process through. One needed a client, a commission and a condition to make this happen. Neither could this ever make economical sense to a practice, nor could it make ethical sense to devalue the unique creative construct of this project by using it as a repetitive tool. The resistance to repetitions and the courage to create contextually relevant architecture reinforced the critical role of architects in today’s times of overexposure to imagery and their visual vocabulary, especially in our indigenous scenario.
As I introspected further, the project and its explanation also refreshed the reality of technology and its role in the architectural expression. Building was not seen as an object or as the product but as an idea and its process. The complex coordination of all the services, the shuttering and the setting up of this technique was an inherent part of the architect’s role. It brought the team to the forefront as a collective and cohesive unit - a phenomenon that has been conveniently forgotten in today’s digital times of emailing drawings to site, Skype site visits and remote controlling and coordinating projects. The smells and the sounds of site work, walks and visits of the design teams, discussions and development of details, adapting to constructional constraints - all bring together an understanding and delivery of architecture that can easily be sensed in the final finished project.
The role of the intuitive and the subconscious was also reinforced - as I juxtaposed the passion in the practice of both his office and mine where ideas were simply conceived and constructed. Architecture should neither be under explained nor over exaggerated in its commentary. The conceptual clarity of ‘dis-aligning’ the rooms to make the street squared was straightforward and sensitive, the play of pauses was acknowledged honestly as a preconceived choice. The earthy texture and the natural veins of the layers of rammed earth were celebrated without any inhibitions in a ‘luxury resort’ setting. This gave every space a dimension and each place a character, which was immeasurable and immersive.
Last but not the least, the dialogue also reassured us of the reality of our design lives. The fragile relationships with our clients, the insecurity towards our own evolution, the excitement of our design expeditions and the politics of our practices where we try to navigate projects without negotiating on the design intent – all universal and eternal to architects.
(This article was part of Walking the Talk, published in Issue#17 of mondo*arc india journal where we brought practicing designers together to discuss one of their own pieces of work and dwell into the finer nuances of practicing design today.)