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The building materials used when building affects the extent of damage sustained by infrastructure during and after natural disasters like earthquakes, hurricanes and floods.

Concrete

Reinforced concrete is one of the most practical and preferred building material in the world. Why? Because it has the ability to regulate the strength required at specific points within a structure, and it can be used at a relatively low cost.  Properly designed concrete structures will resist hurricane force winds and can be made to resist earthquakes. Compared to wooden construction, it provides superior fire resistance, and can gain strength over time.  Concrete structures can also stand against sea swells and intense waves along shore lines and floods. It is one of the most durable building materials.

Timber

Under proper conditions, wood provides excellent, lasting performance.  However, it also faces several potential threats to service life, including fungal activity due to increased levels of moisture. It is also buoyant and this makes timber structures get swept away at high water levels as in floods and sea swells. Albeit timber structures can withstand earthquakes and hurricane force winds once they are well built.

In earthquakes, timber structures have the ability to permit high levels of displacement in the structure due to its flexible joints.  These joints dampen the horizontal forces generated, while sustaining only minimal damage.  Also, since the forces acting on the structure in an earthquake are directly related to its self-weight, lighter materials like wood would be best.

Steel Frame

The steel framed structure is widely used in the construction industry due to steel’s physical properties such as strength, malleability and its ability to be prefabricated. In terms of the ease of erection and overall durability of such structure, these properties make it one of the best materials for construction, but also one of the most expensive materials and methods in the industry.  Like reinforced concrete, it can be designed to withstand hurricanes, earthquakes and floods.

These materials can be utilized on their own or in combination to address the weakness of one, to fit within the budgetary allowance, or to make the structure’s design more interesting.

The prevalence and impact of natural hazards means that special attention should be made in building designs and materials and in employing the right technical professional to lessen tragic loss to property and life.

It is not economically viable to design an earthquake, hurricane or flood proof building which is guaranteed to resist all possible scenarios.  However, it is possible during your design and construction process to select the appropriate materials (to be discussed in next week’s article) and to incorporate a number of disaster resistant features by applying engineering techniques, which would increase enormously the chances of survival of both buildings and their occupants.

Let us start with the geometry (shape of configuration) of a building as it is of equal importance as the maintenance of the integrity of the building envelope which we will discuss a little later in this article.  The geometry of a building is a crucial issue that should be addressed at the conceptual stages of a building project since it affects how well the building can resist natural disasters. Of particular concern are hurricanes and earthquakes; earthquakes to a lesser extent.

We therefore make the following recommendations for light weight structures of two stories or less:

• A symmetrical building shape and arrangement of openings would result in a more balanced distribution of forces in the structure.

• To withstand higher wind forces lightweight roofs should be gently sloping, no less than 20 degrees steep, a hipped shape (sloping in four directions) rather than a gable (sloping in two directions) or a single pitch shape.

• Further improvements in wind resistance to lightweight roofs can be achieved with reduced overhangs at the eaves. The total elimination of overhangs to introduce a parapet wall would improve the roofs performance.

• Shading of doors and windows from the elements may be achieved by the use of canopies separate from the main roof.

• Where existing buildings are of unfavorable shape, making them invulnerable to hurricanes would include protecting windows and external doors. Significant attention should also be given to strengthen the building envelope as a result of the higher wind forces generated by the unfavorable building geometry.

When planning renovation projects, designers should consider opportunities to upgrade both the roof structure and its covering to at least the minimum building regulation standard for safe buildings.

As mentioned above, maintaining the integrity of the building’s envelope, including roofs and windows is very important and can be regarded as the key strategy to protecting a building from high winds caused by hurricanes.  It is imperative that we design structures to withstand the expected lateral and uplift forces. For example,

• Roof trusses and gables must be braced;

• Hurricane straps must be used to strengthen the connection between the roof and walls;

• Doors and windows must be protected by covering and/or bracing.

Further, building designs can be influenced by the level of seismic resistance desired.  This ranges from the prevention of non-structural damage in frequent minor ground shaking to the prevention of structural damage and even avoidance of collapse or serious damage in rare major ground shaking.  These performance objectives can be accomplished through the introduction of structural components such as shear walls, braced frames, movement resisting frames, diaphragms, base isolation and bracing of non-structural components.

Though these suggestions seem to imply limiting creative architectural expressions, advances in technique, equipment and material do permit straying from them safely. This does require the conscious involvement of architects and engineers to achieve beautiful and safe construction which is essential in Dominica.

Are you currently searching for a piece of property to build a home for you and your family? We receive many inquiries from individuals searching for flat land because the fact is that flat land is a bit easier and less costly to build on (depending on the location and design of the home to be built). However, on a mountainous island such as Dominica perfectly flat land is not easy to come by and when they do go on the market they do not usually remain there for very long. And while flat land may be what most individual’s desire, hillside properties are usually excellent real estate for homes for a number of reasons. In this article we are going to look at both the advantages and disadvantages of building on sloped land.

Here are four (4) advantages of building on sloped land:

• Building on sloped land along the side of the hill can enhance the natural ventilation that your home receives. This natural ventilation, while a source of fresh air, also aids in decreasing the energy bills of your home by becoming less reliant on artificial cooling.
• When compared to homes built on flat land surrounded by several other buildings homes constructed on hillsides are relatively more energy efficient. This is because of the natural ventilation (as mentioned above) and because they have better access to natural light.
• Hillside properties often boast magnificent views. Being at a higher elevation allows panoramic views of your environment, whether it’s of the majestic mountains or the tranquil ocean. Having an amazing view from the comfort of your home is something that money cannot buy.
• Building on sloped land forces the addition additional floor levels to maximize space and extend vertically rather than horizontally. Because horizontal extension would require huge excavation or reinforcement costs. Once the additional floor levels are added they can character to the home and variety to the space distribution.

Now that we have looked at the advantages, here are two (2) disadvantages of building on sloped land:
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The traditional approach by home owners to building a home is to develop an idea or plan of what they want their home to look like, then hire a contractor to execute the plan.

Building a home calls for a lot more than just that.  A significant amount of time, financial and material resources go into a construction project.  Considering the scarcity of these resources, their proper management is crucial.

The effective management of resources when constructing a home can be a full time, demanding and stressful job, especially with the hectic schedule that governs the lives of homeowners.

A common component of building a home is selecting the right contractors.  Some contractors will provide excellent service and will need little or no supervision while others will need constant supervision and guidance.  How do you know which contractor you can entrust with your project, with minimal stress and little hassle?  Are you familiar with construction terms, documents, processes and materials necessary to   successfully complete a construction project?

The Project/Construction Manager offers a homeowner considerable relief from the stress and hassle of managing their home construction.  Project/Construction Managers, as well as many homeowners today, understand that building a home isn’t just a huge financial investment, it’s also a great investment emotionally and because of that the practice of project management has become very important and indispensible.

The key responsibility of a Project/ Construction Manager is to accomplish the objectives of the project.  He/she understands that no two customer’s expectations are the same but their common concerns are Cost, Time, Quality and Scope.

Project Cost – Expenses incurred for labour, material, equipment, services, utilities etc.

Project Time –The time frame analyzed and developed for the completion of a project or deliverable.

Project Quality – The totality of features and characteristics of the project at completion that satisfies stated or implied client need and is fit for the purpose for which the project was implemented.

Project Scope – What the project is supposed to accomplish and the budget of both time and money that has been created to achieve these objectives.

As a representative of the owner’s interest Project Managers bear ultimate responsibility for ensuring that key components of the project are efficiently handled.

Construction managers plan, coordinate, budget, and supervise construction projects from early development to completion.  Although many construction managers work from a main office, they spend a lot of time on the field at the construction site where they monitor the project and make daily decisions about construction activities.

They work in support of the homeowner to reduce total cost and ensure the best quality of work.  If nothing else, they can provide the homeowner with much needed peace of mind.