How to build 1,000 villas in a year using precast concrete?
This blog discusses precast concrete technology from the point of view of constructing 1,000 villas in one year. For such a project, in addition to cost savings, speed, quality, safety and sustainability are the benefits reached with precast in comparison to cast-in-situ.
1,000 villas using precast concrete vs. cast-in-situ
The pictures on the right are a great example of the effectiveness of precast concrete technology, because they illustrate the difference of constructing a villa with the same design using the cast-in-situ method versus precast concrete technology. The differences can be discussed through four main perspectives:
1. Speed. Precast construction enables you to build more villas in the same time frame in comparison to using cast-in-situ, bricks and blocks; precast concrete is an industrialized way to build. Because precast components are manufactured at factories, the need for manpower decreases at the construction site. Approximately 50% less manpower is needed while precast panels are assembled two to three times faster.
2. Quality. Producing precast panels at a factory results in consistent quality, not to forget about the sound insulation and fire resistance capabilities of precast. Global, regional and national design principles and standards also help in maintaining and further developing the quality.
3. Safety. Factories are controlled environments, where the machine and employee safety have been thoroughly considered. In addition, less people at the construction site equals to smaller chance for accidents to occur.
4. Sustainability. The main benefits come from the saved materials; roughly 20-30% of steel and cement can be saved by opting for precast instead of cast-in-situ, and energy-efficiency which is better throughout the villa’s lifetime. Note-worthily, cooling down a building is two and a half times more expensive than heating up a building, and thus, it is very important also for warm countries to have proper insulation.
The above mentioned are the basic benefits that we have recognized and calculated all over the world – benefits that also construction companies and developers have acknowledged when changing to the precast technology. The benefits also come with a decrease in costs: time saving, optimal use of raw materials, manpower needs, energy-efficiency of precast buildings and durable construction.
Cost analysis of 1,000 villas
As an example, I will introduce a cost analysis of 1,000 one-storey villas made for a real project, so you can get a better idea of the precast building components needed and their costs. For the built-up area of 169,000.00 m2, 180mm thick load-bearing insulated wall panels with a grey concrete mold / trowel finish, 150mm thick solid wall panels with the same finishes, 120mm thick solid wall panels with same finishes, 150mm thick hollow-core slabs and 200mm think hollow-core slabs are needed. For these the approximate price is 167.23 USD per m2 including factory, delivery, erection and crane costs. For the foundations and grade slab 250mm thick precast concrete footing with a grey concrete mold /trowel finish, concrete grade beams with same finishes and 150mm thick hollow-core slabs are needed, costing approximately 137.99 USD per m2. All the finishing works et cetera are excluded from the prices – the prices cover the frames and the foundations for 1,000 villas.
Ismo Kallio, Vice President Sales
To manage the precast construction of 1,000 villas in one year, we suggest a precast plant with a production capacity of 1,126 m2/day of hollow-core slabs, 585/205 m2/day of load-bearing insulated/solid walls, 230 m2/day of non-load bearing walls and 360 m2/day of foundation parts. With this production capacity, reaching 1,000 villas in a year is easily manageable. Setting up such a precast plant takes approximately six to ten months from the signing of the contract, including the design, manufacturing of factory equipment, transportation and production start-up. In other words, in less than a year you can already produce the first panel.
Regarding the manpower need, roughly five to seven people are needed for the hollow-core plant and 30 +/- people in the wall side when taking into account reinforcements, depending on the complexity and type of the product you are producing.
Key success factors
Before setting up a precast plant and starting a precast construction project there are several key factors that are beneficial for you to know and plan. It is worth remembering that the key factors should support one another. For example, when designing and manufacturing precast components, the lifting capacity and condition of the roads should always be considered. In other words, it is important to plan efficiently and in a detailed manner to have a smooth process from the planning to the assembly. I and my colleagues at Elematic are happy to help you in reaching all the following key success factors, with our over 60 years of experience in the precast business, from your initial interest in precast to the lifetime of your precast plant.
– Feasibility study of the project
– Architectural design
– Selection of building system
– Conceptual design
– Detailed precast panel design
– Project planning
– Production planning
– Production in the factory
– Transportation to the site
– Assembly and other site work
– Teamwork and cooperation (I consider this as one of the most important lessons-learned for a successful project)
Building Information Modelling (BIM) is one of the key issues, because it enables efficient management of all the design phases from the overall design to smaller details. In addition, BIM provides efficient information sharing between design, production and construction, thus enhancing collaboration.
If constructing precast villas or precast technology in general intrigues you, read more about how to adopt precast concrete as your building technology here or send us your questions with the contact form below.
My colleague, Curt Lindroth, also recently introduced precast construction of luxury apartments, Grand Views in Dubai, which might be of your interested: Luxury apartments built with precast concrete in Dubai