Building setback is a mandatory requirement by the Local Authorities (Pihak Berkuasa Tempatan, PBT) for all the types of property development in Malaysia, including landed property such as terrace house, semi-detached, and bungalow type. The setback is a distance between the property line and the land boundary line, which no structure or building shall be allowed within the area. However, some of the property owners tend to extend their house to the land boundary line to maximise land usage and build a more usable living space.
The extension of the landed house is not totally prohibited. However, the property owners would expect some challenges or limitations when extending their houses. The following are some of the challenges foreseen.
PBT understands the requirement of the citizen to having more living space by extending their houses. Hence, PBT provided some loose requirements for landed houses for an extension. They imposed certain limitations for the extension, and the requirements are subjected to different PBT. The property owners are required to engage professional architect or building draughtsman to do proper submission and application to relevant PBT for approval. The property owners shall also ensure the actual construction of the house extension complies with the PBT requirements as submitted.
The property owner is strongly advised to engage professional structural engineer to study and design for the structure of the house extension. Typical property owners would only leave the “design” to an appointed contractor, who normally constructs the structure of house extension by “experience” or “feeling” without proper design. If the contractor is not experienced enough or not feeling correctly, most of the case the owner would face the following problems:
- Uneven Settlement
In most of cases, no provision foundation will be provided for house extension during the earlier house development stage. A new foundation shall be designed for a house extension to sustain the additional weight at the area. Proper foundation design shall be provided to avoid severe ground settlement. Besides, if the foundation is not designed properly, the settlement of the extended area would be at a higher magnitude compared to the original building structure, and hence shearing would be happened and causes building cracking.
Proper sizing of foundation, columns, and beams shall be designed to sustain the additional weight of the house extension. If the construction of the extension is only based on experience and feeling, the columns and beams might be under-designed, and eventually cracking might be occurred due to overloading. Wall cracks could also happen especially at the extension joints with the main building. Hence, it is important to consult a building consultant to design for the extension so that the structure is safe to occupy.
Some extensions will encounter electrical problems like the electrical trip. This is caused by the improper electricity installation during the extension works. Electrical tripping is dangerous which may lead to fire occurs in the building.
The joining between the new roofing and the existing roofing shall be taken care of professionally. Proper sealing and waterproofing shall be carried out to avoid roof leakage from the joining points between the extended and the existing building.
In conclusion, it is advisable to consult with a professional consultant and qualified contractor to plan, design and build a proper extension to avoid any house extension problems that give rise to adverse effects in future.