AUTHOR: ADMIN | DATE: MAY 2019

(This is an idea which highlights the problems in the building construction process which lead to buildings collapsing and suggests ways to overcome these problems.)

OVERVIEW:

Buildings collapse in Nigeria on a regular basis. Old buildings, recently finished buildings, and mostly buildings under construction… they all come down in Nigeria.

The aftermath is the same: outrage; blame; half-hearted investigations; petty arrests; increased legislation; blind over-enthusiasm from the authorities for the next few weeks; and then back to normal… until the next building collapse. The unfortunate truth is this: until the core problems are identified and addressed, not a single difference will be made.
A building collapsing is as a result of a structural failure of the building. But before we speak about why a building has come down, let us discuss how a building is supposed to come up… in Lagos.

 

SUMMARY OF BUILDING CONSTRUCTION PROCESS:

• Note 1: To erect a building, you need drawings of that building. The architect is the head of a design team and is typically the client’s first port of call because he/she has the skillset to realise the client’s desires through the designs he/she produces.
• Note 2: The architect produces his/her basic drawings and shares the drawings with a whole host of other professionals who work alongside him/her to work on. One of those professionals, whose duty it is to ensure the buildings integrity is not compromised, is a structural engineer.
• Note 3: Before you can legally start meaningful construction on site, you need to obtain Building Approval from the State Government.
• Note 4: The design team submit architectural and engineering drawings (along with a host of other support information) to the State Government for building approval.
• Note 5: The drawings must be stamped and sealed to show that whoever has produced these drawings is a trained professional and is a member of one of the trade bodies which govern and sanction trained professionals in that field. The emphasis on trained professionals alone producing drawings is meant to be a guarantee of professionalism and accountability. I.e. you’re dealing with someone who can lose his licence to operate if there is established malpractice – this is a good thing IN NIGERIA.
• Note 6: Since building collapse is as a result of a structural failure, let us focus on the role of the structural engineer in particular.
• Note 7: So, a qualified structural engineer produces, stamps and seals structural drawings for building approval. The structural engineer produces his/her design based on information he/she receives from the architect and client. He/she is told by the architect that a space is to be used for a warehouse – he/she designs a warehouse slab to the loading standards of a warehouse slab. He/she is told by the architect that a space is to be used for a classroom – he/she designs a classroom slab to the loading standards of a classroom slab e.t.c
• Note 8: The government authorities make their comments after going over the documents. There is sometimes a back and forth for modifications and clarifications.
• Note 9: The drawings are approved.
• Note 10: Before construction work commences on site a qualified structural engineer must be engaged by the client to carry out inspections on behalf of the client for the duration of the project – documents are signed to this effect. This is the law. Let us call him/her our consultant structural engineer.
• Note 11: Before construction work commences on site, the contractor responsible for the construction is made aware that they have a duty to invite the government authorities to inspect works at key phases. The phases are explicitly spelt out to the contractor.
• Note 12: Before construction work commences on site the consultant structural engineer would typically ask for the CV and qualifications of the builder (the person leading the contractor’s construction team.) The consultant structural engineer would need to know that a competent person is in charge of building the structure.
• Note 13: During the construction phase the consultant structural engineer ensures that all his/her drawings, details, and specifications are adhered to. Changes that need modifications must be issued by him/her and he/she must be made aware of all challenges faced.
• Note 14: During the construction phase the consultant structural engineer would typically insist on a few things: testing of every single batch of reinforcement brought to site; cube testing of every single batch of concrete poured into the structure; testing of the water and sand being used to ensure there are limited impurities which can undermine the integrity of the concrete. The engineer would insist on seeing the results of these tests during his/her visits and failure to provide these tests could lead in instructions being issued for that untested component to be demolished and carted away.
• Note 15: During the construction phase the government authorities would also visit site during key phases – they would inspect critical aspects, ask for test results ensure safety standards are being adhered to e.t.c.
• Note 16: The structure is put up safely. The structure is sound. The structure is used for what it has been designed for. Everybody is happy.

The process described above works in Nigeria. If this process is followed through there will be no problems. But the process described above is only followed through in a tiny fraction of the buildings which are erected.

 

KEY ISSUES:

1. A lot of construction work commences on site without the proper approval documentation being obtained. Meaning that contractors start work on site with drawings which could have been prepared by absolutely anybody. Drawings which have NOT been vetted by anybody. This leaves an obvious problem with the basic integrity of what is being built.
2. Government authorities are there to counter illegal structures from being erected. However there are not enough trained personnel in the government departments to track illegal constructions. In cases where construction sites have been sealed by the authorities because of a lack of documentation, it is very common to see work proceeding regardless because the enforcement is slack, and in some cases appeasements have been made.
3. On site, very rarely is a qualified structural engineer engaged to inspect the construction process as is the legal requirement. Work on site is supervised by unscreened builders who are accountable only to their clients – clients whose primary interest is to deliver the cheapest building possible.

The offshoot is thus:

• Nobody invites the government authorities to site as and when necessary during construction;
• Nobody has vetted the person in charge of the construction. Now, the emphasis on the skillset of this individual isn’t necessarily an academic one. But typically a consultant structural engineer would want to know that whoever is supervising construction on site has a well-rounded construction knowledge. Without a consultant structural engineer to vet the competence of the builder and inspect construction work as it is ongoing, sheer luck and not providence becomes the driver of the process:
  • Can the person read drawings? Does the person understand basic structural principles – which members are in tension and which are in compression? Does the person know when to test materials? Does the person know best safety standards? Does the person know how to prop a suspended slab to be cast? Does the person know how long a suspended slab is meant to remain propped after casting? Building designs change all the time during construction – does the person know how to make modifications to structural elements? E.t.c
  • Imagine if the answers to all the questions asked above is “no”?
    • Buildings constructed with no reference to structural drawings; Untested materials used; modifications poorly dealt with; impurities in concrete; poorly done and dangerous work allowed to remain because it is too expensive to modify; slabs de-propped too soon; slabs not propped properly; no input from the government.

A combination of one or all of the above plague majority of the ongoing construction projects in Nigeria. The number of collapses during construction is astounding and in truth only a fraction of these stories actually make headlines.

 

LONG STANDING BUILDINGS:

• Landlords and government authorities have the duty to ensure that a building is used for what it was designed to be used for. See note 7 above: A structural engineer will design a building to the parameters defined by the client and architect. He will leave a lot of tolerance but tolerance can only get you so far. A domestic residence is built, if in a few years down the line the building changes hands and all of a sudden the new client wishes to use the building as a data centre and start storing servers in a place designed for beds – problems will occur. The government officials need to realise that grating permission to change the use-class of a building has structural repercussions on the building.
• Concrete framed buildings typically show signs of impending failure before they completely collapse – a twisted column here; a beam deflecting there. The occupiers of these building and the general public at large must be informed of who to speak to when these signs of impending failure become evident.

POSSIBLE WAYS TO REDUCE INCIDENCES OF BUILDINGS COLLAPSING

• Properly train and recruit many more government officials to the building control departments.
• Properly train and recruit many more builders & civil & structural engineers than the system currently churns out.
• Provide incentives for members of the public to notify government departments when new construction work starts, so legality of construction can be ascertained.
• Budget for enforcement needs to be significantly increased.
• Judiciary must be brought on board – quick prosecutions, fine and possibly jail for clients who: fail to submit drawings for approval; commence work on site without approval; do not engage licenced structural engineers to inspect construction projects.
• Whistle-blower policy with incentives to catch out government officials who are open to appeasements.
• Explore ways in which the private sector can come on board in the process. Using u.k. privatization of building control as a possible template.
• Launch a determined drive to prosecute manufacturers and distributors of fake and sub-standard building materials in the country.
• Make building’s insurance compulsory.
• Insurance companies will be obligated to engage structural engineers to inspect buildings during assessment & evaluation stage.
• Defects noted will be passed on to owners & government for immediate remedial works.
• Building owners are less likely to shirk their repair obligations or fear defective building demolition if they know the structures are insured.
• To ensure insurance remains valid, owners will be obligated to use the buildings for the purposes they were constructed, or carry out necessary upgrades if a change of use is so desired.
• Sensitize the general public on who to call if building defects are observed.
• Overhaul existing building control guidelines to ensure mandatory structural tests for buildings which undergo a change of use.
• Professional bodies must come together to draft a coherent building code.
• Extensive public relations / outreach and grass roots consultations / conversations for buildings which have to be demolished.