Shop alterations: toilets, central air-con, mezzanines and partitions

Most alterations are possible, but each needs two answers before you build: does the landlord consent in writing, and does the council (and sometimes Bomba) need to approve it? Interior work that does not touch the structure, the plumbing or the escape routes usually needs only the landlord. New toilets, mezzanines, structural openings and raised floors also need approval. And whatever you build, agree now whether it stays or must be removed when you leave.

This is general information, not legal advice. Confirm approvals with your council (DBKL, MBPJ, MBSJ) and an architect before work starts.

Usually yes, with consent. Partitions left by the last tenant are often light walls that come down easily, and many tenants prefer a clean shell. Two cautions. First, walls around the staircase to the upper floors may protect the escape route, so do not touch them without an architect. Second, if a partition is on the approved plan, removing it may need the council's say, and councils may ask about partitions when you apply for your licence. If you knock down the landlord's walls, the agreement may require you to rebuild them at the end; get it in writing that you do not.

Yes, if three things work:

• Power. Big systems draw heavily. Check the supply rating at the meter board; an upgrade involves the landlord and the utility, and takes time.
• Outdoor units. They need a place on the roof, the rear wall or a ledge that the landlord, the management (for strata) and the council accept. Front facades are often restricted.
• Drainage. Condensate pipes must run to a drain, not onto the five-foot way.

In a single shoplot, "central" usually means a ducted or multi-split system serving the whole floor. It can be done, but the ceiling must hide the ducts, the roof or rear must hold the condensers, and the landlord will want to know who owns the system at the end. Agree whether it stays as a landlord fixture (often worth a lower reinstatement bill) or is removed.

Often, but it is one of the harder changes. A toilet needs a sewer connection, ventilation and waterproofing. If the new toilet is far from the existing pipes, the floor may need to be cut or raised to get a fall for the pipes. Treat it as building work needing approval. Many shoplots already have a rear toilet on the approved plan; using or upgrading that one is cheaper and simpler than adding another.

Yes, commonly for F&B, salons and clinics. Water points branch from the existing supply after the meter; drain points need a fall to the rear drain and, for food premises, a grease trap. Cutting the slab for floor traps is where cost and approval questions start. Our guide to exhaust, 3-phase power and water points explains what an F&B unit needs, and how to find a shop with them already in place can save you the work.

Raising the floor with a screed or platform is common to hide pipes, but it cuts ceiling height, creates a step at the entrance and adds load. Lowering a slab is structural and rarely allowed. Check the effect on the shopfront door, the five-foot way level and access for customers. Reinstatement risk is high: removing a raised floor is costly.