In the age of limited space for living, extension to the existing building is a common phenomenon and perhaps, building a home is a never ending process. It is true that you made your house considering all possible aspects of a comfortable living, but as time passes, extension becomes inevitable due to further space requirement with changing life style.
Extension in an existing building requires a fresh set of thinking on the new look, present architectural strength and air ventilation after extension. The most common mistake people commit is not considering proper counselling from an architect, who can render his expertise on required alterations.
Before any extension, you should check the strength of the present building by examining the technical drawing, which was implemented for the original construction. Many a times, people raise the third floor, where as the plinth of the building supports only up to two floors. It results in poor strength and is prone to danger, especially at the time of natural calamities like earthquakes and storms.
A balcony may be planned for a better living, by projecting the roof. But before that you should check the potential of the load bearing wall. Will this wall be able to tolerate the weight of extra beams and roof meant for the balcony? Similar queries may be thought of when you add some modern facilities like roof-top swimming pool, garden, etc. When you plan for some water storage on the roof, you should follow the specific water-resistant construction methodology.
Sometimes, extension in a building results in blocking some existing windows and ultimately results in poor light and air circulation inside the house. In the long run, it becomes unhygienic to live in these houses, resulting in ill health of family members. Also, the plumbing and electric connections should be taken care of, at the time of extension. With improper planning, provisions like sewerage system, water line or drainage systems may be blocked, thus creating problems for future maintenance.
Most of the people think about extending their building considering immediate needs. They go for a garage, when they buy a car and gradually go in for a servant room, pet room, storage space, lift, etc. This style of repeated unplanned extensions, results in an odd shaped building, which seems as if too many match boxes are dumped in one place.
Technically speaking, each and every architectural structure has loopholes. But some mistakes turn out to be blunders at the time of building an extension, as they involve lot of cost and are practically irreversible. So whether it is a small extension of 100 sq. ft. area or another complete floor, same magnitude of attention should be given before, as well as at the time of construction. Maintaining the level of floors in old and new spaces, heights of doors/ windows and air circulation are some of the prime features that must be taken into consideration at the time of extensions. Otherwise, even after investing a huge amount, one will be compelled to live with compulsions.