Friday, 14 December 2018

How To Obtain Layout Approval And Building Plan Permit For Your Estate - Engr. Osaz’ ENOBAKHARE

Having a Global C of O for an estate is not the same as an approval for that estate as unsuspecting property shoppers are often cajoled to believe. The Global C of O like every other land titles actually pertains to the land not necessarily the structures or activities on that land. Some estate owners are either unaware of this fact or choose to deliberately ignore it thereby putting subscribers at a great financial and ownership risk. There are reported cases where built-up Estates have been demolished due to lack of estate layout approval and building permits and people have lost millions and their beautiful homes. To secure a full estate layout approval and building permit for your estate (especially in Lagos), follow these simple steps;

-         Get a perimeter survey – a perimeter survey will capture the distance round that estate from a reference point back to that point. It will ultimately show the total area of the estate as well as the length, breadth and overall shape of the estate land including adjourning features like roads, water bodies, etc. The survey is prepared by a Land Surveyor. Traditionally all survey plans are lodged at the office of the surveyor-general. In order to regularize this survey, you will be required to pay certain processing fees; part of which will be used to obtain the beacon sheet from the relevant office. The perimeter survey is needed for the next stage which is to plot out the estate layout.

-         Plot the estate layout – every estate should have a layout. This layout shows the entire positioning and arrangement of structures and infrastructure on the estate land together with the topography and other essential features. It is traditionally the function of a Town Planner to prepare this document. The Estate Layout is different from an Estate Plan which is prepared by an architect. In a typical layout drawing, you see various blocks carrying different colors each having a distinct meaning. Medium-density zones are so identified, so are low-density and high-density areas. The same also applies to core residential zones, commercial and mixed areas. After preparing the layout, the next phase will be to submit the layout for government approval.

-         Submit the layout drawings for approval – Once the layout is submitted for approval, it goes through a process of scrutiny to determine whether the purpose of use of the land is in sync with the already established zoning requirement. The arrangement of spaces within the estate is also checked for consistencies with established planning regulations in that city. If there are discrepancies, it might not be approved. Occasionally, it is returned for corrections or adjustments. If successful, the estate is now officially recognized. Next line of action will be to apply for building approval/permit. To get this process underway, you would have to prepare the required designs.

-         Prepare the architectural and engineering drawings – You would have to engage a registered architect in preparing the architectural drawings of the entire buildings in the estate. He would be required to apply his/her ARCON stamp and seal to the drawings as so required. Then the structural engineer will prepare the structural drawings. He would present it along with a letter of supervision or engineering report where applicable. A professional builder can also present a letter of supervision with regards to building projects with his/her CORBON seal affixed. The other engineering drawings are prepared by the relevant engineers usually the Mechanical and Electrical Engineers. A comprehensive soil test report from which the structural design would derive basic foundation design parameters would also be required.

-         Submit your building drawings for approval - Armed with all the relevant building drawings, signed, stamped and sealed, you approach the planning authority to obtain approvals. You will be required to pay processing and approval fees. In the course of this approval, all the drawings would be scrutinized for consistencies with the relevant codes of practice and statutory regulations. A physical inspection of the site would also be carried out. The aim will be to compare the paper work with actual site conditions. If satisfied, an approval will be given with an approval number issued. Where the estate has been partially or fully developed prior to filing for approvals, an engineering report will be required which will certify that the buildings are fit for habitation after a non-destructive integrity test ‘’NDT’’ has been carried out. 

It is very important to obtain the layout and building drawings and approvals for your estate in order to avert the risk of losing your property. You can contact the author for further discussions.

Why It Is Important To Conduct A Soil Test (Investigation) Before Construction - Engr. Osaz’ ENOBAKHARE

Most structures are earth-laid and it’s in your best interest to know what the earth feels about what you are about to construct over it. If you really don’t care and the earth doesn’t feel good about your ideas, you are heading for disaster. Investigating the condition of the sub-soil upon which a structure will be built is a process that should not be undermined and must be carried out diligently. Every building is supported by a foundation, making it about the most important component of a building. The foundation itself, no matter how strong could be unreliable if it does not sit firm on the ground hence the need to understand where and how best to place it.

The process of determining how the earth would accommodate the foundation first begins with carrying out a sub-soil investigation. It goes by the saying ‘what you don’t know can kill you’; for instance, if you don’t know that at 1-metre depth the subsoil on your land is too weak to support your proposed structure and you go ahead to place your foundation there, the result is likely going to be disastrous. 

Soil test for construction purposes, otherwise referred to as sub-soil investigation is different from the process carried out to test the biological and chemical properties of a soil in order to know if it can accommodate the growth of certain plant species; ofcourse not! It actually involves the physical examination of the soil from layer to layer to determine its type, density, strength characteristics (bearing capacities), consolidation potentials, rate of soil settlement, water table and other relevant data. This information is useful to guide the structural Engineer in determining the most suitable type of foundation to support the proposed structure, the most suitable depth to terminate it and the overall design of the foundation. The test also helps predict problems that may arise during and after construction and how they can be properly dealt with.

Usually as the major scientific step before construction, geotechnical information from soil investigation also helps in determining a more reliable construction cost estimate for a proposed project. On live projects, a simple soil investigation can influence a foundation design that can put the cost of construction significantly in excess of what was originally budgeted; hence the need to conduct a soil investigation before arriving at any meaningful construction budget especially in a joint venture (JV) or concession arrangement. 

In Nigeria, a standard soil test report prepared by geotechnical personnel is a pre-requisite for structural design approval especially for buildings that consist of more than one floor. The most common soil tests for building projects back here are the Dutch-Cone Penetrometer Test (DCPT) and the Cone Penetrometer Test (CPT). While the former is quite simple; can be concluded on-the-spot within a few hour and is mostly useful for buildings not more than two-floors, in the latter a rig is deployed, it is more comprehensive and would normally require laboratory analysis of samples taken from site. It is standard practice to test at least two points per plot of land for DCPT and at least one trial pit and borehole of CPT on the same size of land. 

A standard soil test report consists of a soil profile showing the various layers of soil and their physical and geotechnical characteristics. It would normally show the procedure adopted in the carrying out the test together with graphical and numerical data both from on- the-field results and those computed based on established empirical formulae. In the end, the geotechnical personnel or structural engineer is able to ascertain whether or not a shallow or deep foundation is okay to sustain the proposed structure. Most report would enlist a range of suitable foundation types based on the information available on the size and load characteristics of the proposed structure. 

Combining Raft And Pile Foundation On The Same Structure Can Save Cost - Engr. Osaz’ ENOBAKHARE

Anything to reduce cost and still maximize benefits goes in today’s world. Sometimes we find ourselves with only a few options but we can still explore them. Unlike short bored piles, constructing deep piles are normally expensive compared to raft foundations because not only would the piles be installed using various machines or equipment they usually will have large caps and beams constructed over and connecting them respectively. Therefore when cost becomes an issue you can find an acceptable way to run the race and win the prize. Where practically possible and technically okay, a combination of two or more foundation types can be adopted. In practice both raft and pile foundation can be used together on the same structure to achieve a foundation that performs excellently under load and still reduce overall cost and when you choose this option, there are several factors to take into consideration.

For instance you intend to put up a block of 8 flats on four floors; 2 flats per floor and your soil test report allows you to combine pile and raft foundations dependently or independently without necessarily specifying where either of the two should be used, you can in agreement with your engineer/builder opt to use pile on one wing and raft on the other. In other cases, project owners who intends to build semi-detached duplex and bungalow together or semi-detached duplexes or terrace houses or even two separate buildings lying side by side to each other can use a combination of pile and raft foundations perfectly. The type of foundation arrangement discussed here is not the same as combined Pile Raft Foundations (CPRF) which is achieved by constructing raft over existing piles instead it is about the use of two different foundation types in different locations on the same building or buildings sitting close to each other on the same land.  However in any case, it is important to follow the lead of the soil investigation before venturing.

To get the procedure right, basically obtain a geotechnical report (soil test) to know the soil strata and bearing capacities at various depths. Pre-inform the geologist or structural engineer handling your soil test of the type of structure and your intention to combine raft and pile foundation so they can compute various strength characteristics in line with your option. A lot of technicalities are involved in the combination of these two types of foundation especially for the same building but engaging a professional structural engineer will make the work look very easy and the resultant cost reduction is amazing!  For instance the interaction between both foundation elements and the subsoil to achieve maximum functionality are primarily hinged on the characteristic pile and base resistance to load and against settlement hence the foundation must achieve resistance that is sufficient enough not to fail or settle excessively or inordinately at any given time. Also, the internal and external bearing capacities of both foundation elements which border largely on strength of materials used and bearing pressures exerted on, by and around the foundation respectively should be properly analyzed. If you get your procedure right you would have cut some 20% off your foundation cost and that’s huge savings especially on a large scale.

Thursday, 13 December 2018

Converting an Office Complex to an Enveloped Shopping Mall: Thinking Aloud!

      Converting an Office Complex to an Enveloped Shopping Mall: Thinking Aloud!
                                                                                  Engr. Osaz’ ENOBAKHARE

As towns metamorphose into cities and cities develop into mega cities, the quest to create decent shopping malls continue to rise. The advantages a shopping mall over a regular market is huge ranging from the presence of co-ordinated ample parking spaces to giving shoppers the extra opportunity to shop and get entertained at the same time. Truly, the ever soaring mall culture has made owning a mall a big business not only in Nigeria but the world over. Most shopping malls have a collection of shops, stores, restaurants, cinemas, services outlets (e.g. e-banking outlets), etc. offering a wide range of affordable products and services to a vast number of people in a more convenient ’cashless’ manner and fit perfectly into densely populated residential as well as commercial areas. Modern (enveloped) shopping malls class themselves higher than the traditional open shopping complexes because of their envelope design that allows for central cooling of all the shops or outlets throughout the day as well as proximity advantage for quick shopping in the building.  Generally shoppers feel a sense of peaceful ambience and safety in enveloped shopping malls than the traditional type.  
There is still a huge shortage of enveloped shopping malls across towns and cities in Nigeria and the demand is relatively high. Viral pictures taken and shared by mall users during weekends and festive seasons which normally show crowd rush only provide more evidence to this assertion.
Recent industry estimates have showed that the financial returns developers derive from owning classy multi-occupier shopping malls are now scaling higher than what obtains from an office complex of the same size in the same location. This is forcing more and more developers to think aloud on converting existing office buildings or spaces existing in shopping hotspots into ultra-modern shopping malls.
Converting an office building into an enveloped mall like other conversion projects would first require that a thorough assessment is carried out on the building to identify its load-bearing and non-load bearing components. Sometimes, it becomes imperative to conduct an integrity test on the major structural components of the building to ascertain their current strength parameters (especially if it is an old structure) as naturally, shopping malls are designed to accommodate more live loads due to heavy human traffic and movement of heavyweight goods and furniture than typical office buildings.
The way office buildings are partitioned is quite different too, hence the need for very detailed conversion architectural and engineering designs which may compel the use of shoring techniques to reposition some load-bearing columns, beams and walls.  Attention must equally be given to the use of high quality aesthetic interior and exterior finishes as a selling point. For enveloped malls, there is often the need to redesign and reconfigure the entire lighting and cooling systems as well as the transport mechanism within the building too. The conversion process demands paying attention to a lot of details but once the mall is set, everybody smiles.