Sumit Maity & Shalini Maity give an architect’s perspective on Prefab Technology based on the large prefab housing projects undertaken by them.

Prefab Housing

Civil Construction in India has not been as much industrialized as it has been in the West. Presently, it shares barely 1-2% of the real estate market, though as per a recent study, it is expected to grow @8.5% in the decade of 2016-2026. Several reasons are attributed to the ‘late blooming’ of technology-driven constructions in under-developed and developing nations, which mainly include high initial cost, low labour wages, scarcity of knowledge and skill, unreliability of continuity of work, and also a prejudice against precast technology.

In 2012, the national housing shortage was estimated by the Technical Group as 18.78 M, out of which more than 95% was for the lower income category. It is important to keep this data in mind, as the visual exposure of ‘precast construction’ in the low- income housing is much higher than those in the commercial and other large projects. Where the other large projects can have fancy façades veiled around the precast building skeleton, the low income housing have to be technology-smart with boundary level optimized components without any cosmetic wraps.

Intervention by Architects
Architects’ duty would be to look at prefab technology not merely as a technological tool for faster construction, quality assurance, early delivery and its related economic gains etc. Their creative abilities can turn the otherwise ‘perceived repetitiveness’ of pre-fab into ’rhythmic aesthetic’, a rudimentary mechanized product into ‘simplistic elegance’.

However, as the technical initiator of a project, on a broader perspective, few issues remain from an architect’s point of view:
  • Appropriate stage for deciding about technology.
  • Importance of basic knowledge about pre-casting and component joinery.
  • Understanding of potentials and limitations of a technology.
  • Understanding the resources and capacity of the agency.
  • Architects Intervention- structural modulation and component modulation.
Housing projects of DDA using Prefab Technology
In 2008-09, the Delhi Development Authority initiated large housing projects to be constructed with precast technology. However, as per their recent practice, housing jobs are tendered on design-build model, which include works from initial concept preparation to completion. Till date, about 60,000 houses have been built with prefab technology and about 13500 houses are under construction. All these projects are executed by B.G. Shirke Construction Technology - the pioneers of prefab technology in India.

EWS Housing Project of DDA (2010 – 2013)
Delhi Development Authority came out with a tender in the design-build model specifying RCC Prefab Technology as mode of construction.

Prefab Housing

A total of 20,000 dwelling units each of carpet area 25 sqm were constructed on 9 housing pockets, with a total site area of 46 HA. The total plinth area of approx. 6,50,000 sqm was built in ‘G+4 floors’ configuration. As a precast construction, structural elements like columns, beams, slabs, and stairs were all precast with AAC block masonry infill walls.

Prefab Housing

Fulfilling rigid tender conditions of unit area of 25 sqm and G+4 configuration, a prototype building with 3 stairs and 12 units at each level was developed. In the absence any other variation in built form, the urban scape relied heavily on the green spine networks - pedestrian connectivity

LIG & EWS Housing Project of DDA (2013- 2018)
Prefab Housing
This tender also came out in the design-build model, specifying RCC Prefab Technology as mode of construction.

A total over 34,000 dwelling units (LIG type) with carpet area of 35 sqm each and EWS type of carpet area 25 sqm each were constructed on 10 housing pockets, with a total site area of 67 HA. In total, about 27,850 LIG units with total plinth area of approx. 14,24,000 sqm were built in G+12 floor configuration, along with about 6,200 EWS units with a total plinth area of approx 2,10,000 sqm built in G+4 floors’ configuration.

The precast construction method for the EWS remained the same as in the earlier ones, wheresas in the LIG buildings, a combination of RCC wall panels and columns, beams, slabs, stairs, and parapets were all precast with partial AAC block masonry infill walls.

Tender stipulations for the unit carpet areas were very rigid, though without any capping on the building height. Since the available FAR needed to be consumed in each site, here, the architectural modulation strategy was different. Ten identical units with a lift lobby and stairs were used to make a block – L10, and similarly with eight units and stair block, L8 and L8a were developed. None of these blocks could make a full-fledged building, but combining them at tandem, with 3, 4, 5 or 6 blocks, building-clusters with varying semi enclosed open spaces were achieved.

Prefab Housing

Cat-II (MIG) and EWS Housing of DDA (2015-2019)
Unlike the earlier ones, this tender was technology neutral, BGS won the tender and could continue in prefab considering their previous experience.

A total over 4,900 dwelling units –Cat-II type with carpet area of 77 sqm each and EWS type of carpet area 29 sqm each were constructed on 2 housing pockets, with a total site area of 8.75 HA. In total, about 665 cat-II units with total plinth area of approx. 82,000 sqm were built in 2B+S+13 floor configuration, along with about 4200 EWS units with total plinth area of approx 2,20,000 sqm built as G+15 floors. The construction method used in both the building typologies are a combination of RCC wall panels and the columns, beams, slabs, stairs, parapets were all precast with partial AAC block masonry infill walls.

Prefab Housing

Ongoing 3BHK, 2BHK, & EWS Housing of DDA
This tender was also technology neutral and was won by BGS. A total of 13,450 dwelling units - 3 BHK type with carpet area of 100 sqm each, 2 BHK with 77 sqm, and EWS type of carpet area 29 sqm each are being constructed on 9 housing pockets, with a total site area of 51 HA. In total, about 3000 units of 3 BHK, 6,200 units of 2BHK, and over 4200 EWS units with total plinth area of over 23,00,000 sqm were built in 2B+S+12-18 floor configuration. The construction method in both the building typologies are a combination of RCC wall panels and the columns, beams, slabs, stairs, parapets were all precast with partial AAC block masonry infill walls.

Architectural expression attempts to breaks the otherwise perceived monotonous prefab façade using diverse components in a rhythmic manner. A simple panel with a circular void is used as a signature component, which continues to smaller blocks like a gate house.

Prefab Housing

The ongoing DDA project does exhibit the potential of prefab technology going beyond low-income housing in the Indian context. Somewhere it also says the relevance of issues raised earlier to bring out the best result with prefab technology.

About the authors:
Sumit Maity, B.Arch (Cal-gold medalist), M.Sc –Urban & Regional PLG (UK) and Shalini Maity, B.Arch (SSAA) are from Sumit Maity Architects. Practicing in Delhi since 1999 they have won several national and international architectural competitions.
Elematic's Large Precast Concrete Plant for My Home GRAVA Project
Hyderabad is witnessing the construction of Asia's tallest towers with a planned built-up area totalling 3.7 million sqm. The two 180-meter towers, each comprising 43 storeys, will be accompanied by six more similar towers. With each tower

Read more ...

Benefits of Shear Keyed Surfaces in Precast Building
Depending on the finish of the concrete surface, different coefficients are assigned by international codes in the calculation of shear resistance. The American Concrete Institute Code ACI318, Nov.19, states the following: Chapter 16.2.1.1 – Transfer of forces by

Read more ...

Revolutionizing Precast Industry with Advanced Tracking of Precast Concrete Elements
The precast concrete industry is undergoing a transformative change with innovative software solutions that offer enhanced tracking of precast concrete elements. One of these pioneering software solutions is StruSoft’s Impact Precast, which aims

Read more ...

Emerging Trends & Growth of the Prefab Industry
Prefabricated technologies are becoming increasingly popular in the construction industry, particularly for large-scale construction. As prefabricated structures continue to evolve and improve, they are being used to construct warehouses, factories

Read more ...

Precast RCC Structures versus Pre-Engineered Steel Structures
A comparative study on Industrial Building Adopting Structural Frames as Precast RCC and Structural Steel Frames with Prestressed Precast Hollow Core Slabs as Flooring Slabs, presented by C. A. Prasad, Director, METEY Engineering Consultancy, Hyderabad

Read more ...

My Home Mega Project Shows Potential of Precast Construction Technology in India
Storey by storey, Asia’s tallest precast towers with a total planned built-up area of 3.7 million sqm are rising towards the sky in Hyderabad. These two 180-meter towers of 43-stories each will be followed by six more similar towers. With each tower

Read more ...

Mekuba: A Leader in Mould Releasing Agents for Concrete
With over 47 years of experience in the petrochemicals industry, and an expert in the formulation and production of mould-releasing agents, Mekuba Petro Products is growing rapidly in the construction chemicals segment with a daily production

Read more ...

Dextra Groutec Coupler - A Unique Solution for Reliable Joints in Precast
Dextra has added yet another customer-centric, innovative, and custom engineered product - the Groutec Coupler - an efficient product that has been qualified and tested successfully on several major infrastructure projects in the recent past. With the

Read more ...

India an Important Market for TOPWERK
Sachin Shetty, India Head – Operation & Sales, and Rajesh Jha, India Head - Sales & Market Development, TOPWERK INDIA, discuss the potential of precast concrete construction in India, localization of non-critical components to bring down cost, and the possibilities of digitalization

Read more ...

Vollert: Building A Stronger India with Precast
Vollert India has recently expanded its production capacity in Sikandrabad (UP) India. As a global leader in precast concrete components, systems, and machine solutions, Vollert’s investment in India indicates a growing interest among German companies

Read more ...

Precast India Connector - Helping Precasters Overcome Cost & Time Overruns
Precast India Connections, a new entity of Precast India Infrastructures, has innovated and patented a method of achieving a Dowel-Sleeve connection that functions even in the horizontal direction. Kapilesh Bhate, MD, Precast India Connections, shares

Read more ...

Prensoland Modern Precast Floors Appearance of the iHCS
Pre-stressed concrete hollow core slabs used for building floors are unidirectional members; they are laid one next to the other until the complete carpet area is covered. In the presence of lateral loads like wind, or due to seismic episodes, they behave

Read more ...

Vollert India Expands Production Capacity
The expansion of the Vollert plant in India marks an important milestone in the company’s commitment to provide high-quality products to customers. With the increased production capacity, the company aims to expand its market share and strengthen

Read more ...

Brimax AAC: An Indian Lighthouse Project from HESS AAC SYSTEMS, Netherlands
Brimax AAC Products LLP contracted Hess AAC Systems to supply a new AAC plant in Vadodara, India, with a capacity of 680 cbm/day (expandable up to 900 cbm/day with reinforcement for panel production). This order strengthens Hess´ position as

Read more ...

Vollert India Expands Production Capacity to Cater to Infra Development Sector
Vollert India, based in Sikandrabad, near Greater Noida (UP) since 2017, is strengthening its commitment to India; it is now expanding its production capacity of precast machinery and components to meet the greater demand from India’s fast

Read more ...

Elematic Precast Technology Solutions for Building, Industrial and Infra segments
Elematic offers a comprehensive range of precast technology solutions for the Building, Industrial and Infra segments. Elematic precast technology enables clients to automate the production of walls, slabs, columns, beams, and stairs, providing an efficient

Read more ...

Advanced Concrete Curing Systems from Kraft Curing
Kraft Curing Systems GmbH is offering advanced concrete curing systems that optimize the hardening process of concrete. Kraft Curing’s Advanced Concrete Curing System provides numerous solutions, from vapor-based (steam) systems mainly for the precast

Read more ...

Why Automating Production is the Solution
Automating the production processes will lead to reduced wastage, fewer errors, more precision, greater safety, and higher quality of the end-products, and in a shorter period of time. First, we need to understand where we stand today as regards industrialisation

Read more ...

Elematic India confident of the future of Precast Business
Elematic India sees growing demand for its precast plants in India due to the growth in precast construction across segments. What gives the company an edge is its ability to support the customer through the entire value chain. Says Sridhar Rao, Sales

Read more ...

F.B.I. Tasbud Partners With Progress Group
Progress Group is helping companies like Tasbud stay ahead in a changing market with automation and software integration. Automated machinery to produce precast elements as well as the reinforcement and the integration of the fitting software are

Read more ...