How to construct low-cost housing

Housing is universally considered the second most important basic need of man after food. Its impact on the health, welfare and output of man cannot be underemphasized. For example, having a good house to return to after the day’s work brings a certain comfort.

Thus, housing plays a vital role in a person’s standard of living and place in society. In fact, affordable and decent housing is a basic right for everybody because, without stable shelter, everything else falls apart.

According to a survey conducted by the United Nations in 2005, about 1.6 billion people live in substandard housing and 100 million are homeless. Unfortunately, those figures would likely be double now.

Low-Cost Housing

Low-Cost Housing is a new concept that deals with effective budgeting and the following techniques which help in reducing the cost of construction through the use of locally available materials and eco-friendly recycled materials along with improved skills and technology without sacrificing the strength, performance and life of the structure.

The Roles of Professionals in the Construction Industry

Globally, providing affordable, decent, quality and attractive housing is usually seen as the responsibility of the government. In fact, our governments have to produce affordable housing — they have to produce answers. It is their core responsibility to develop infrastructures to create an atmosphere for economical development. Thankfully, at the forefront of infrastructural development are the professionals in the construction industry, particularly civil engineers.

Civil engineers, in collaboration with other professionals, are tasked with the responsibilities of planning, designing, building, supervising, operating and maintaining infrastructural projects and systems in public and private systems. Therefore, to achieve the goal of constructing houses at the lowest possible cost, they might have to start looking away from the construction techniques and materials we currently employ in order to truly make housing affordable for everyone, particularly for minimum wage earners.

Minimum Standards

In the construction industry, common specifications, methods and procedures are very important to ensure greater reliability and consistency in terms of the quality, compatibility and compliance in the construction of buildings. Hence, there are minimum requirements for standard accommodation.

It is clearly visible that the cost of construction of a building is directly proportional to the area covered. In low-cost housing, the economy in construction is an extremely important factor, but one should not lose sight of the fact that any economies affected are not worth it if the minimum requirements of the basic physical comfort in the dwellings are not met. In order to meet these twin requirements of economy and comfort, one has to depend, to the maximum extent, on cost-effective construction technology to provide minimum standard accommodation.

Taking Nigeria as a case study, the current national building code and housing standards across the states of Nigeria adopts the following (among others) minimum standards: Living room — 15 sq.m; Bedroom — 13.6 sq.m; Kitchen — 6 sq.m; Dining — 7.5 sq.m and Store — 1.5 sq.m.

Cost-Effective Construction Techniques and Materials

In any construction project, building materials form one of the main items of expenditure and can make or break a construction budget. Hence, materials with the lowest cost implications should be given priority. But again, the construction technique and quality of construction materials should not be compromised just for lowering the cost, as this can cost a project irreversible damages in the future.

In lieu of extensive research and development works that have taken place at various research centres to use local materials, waste materials and prefabricated structural components to reduce the cost of construction, the following are some of the improved cost-effective techniques that could be used in building projects:

Architectural Drawings: One of the things that add up the extra cost to a building project is a fuzzy plan that is full of curves and complexities. Since plans represent a very large part of construction costs, it is necessary to observe with continuous attention. Thus, every single detail and complexity of the plan, and cost of construction should be evaluated.

Foundation: Under-reamed piles for foundations have been developed for housing in the black cotton soil areas. Also, the depth of a building foundation is usually 0.9 – 1.2m deep in the soil, but this can be altered to around 0.6m in depth for typical soils. Adopting this can save a lot of time and total foundation costs, but in other delicate or soft soils, the cost reduction objective may not be fully attained or executed correctly.

Walls: Soil-cement blocks, fly ash bricks, precast hollow concrete blocks (without plaster), brick panels and precast wall panels may be used to get reasonably good comfort with little cost.

Doors and Windows: Precast R.C.C. frames can save 25 to 30% cost when composed with wooden frames. Instead of wooden shutters particle board shutters may be used.

Lintels: Locally available stones and slates can serve as lintels.

Precast Structural Elements: In mass construction works, precast members may be used for columns, beams, reapers and staircases. One can think of using wall panels too.

Roof Units: A.C. sheets, cement bonded fibre sheets, paper corrugated sheets, lime and fly ash cellular slabs, solid planks, slates, ferrocement roof units etc. may be used for low-cost housing roofs.

Flooring: Low-cost housing flooring may be with soil-cement base, thin clay tiles, bricks on edges or flagstones.