Your A&A Renovation Can't Legally Begin Until Someone You've Never Met Signs Off On It
Most homeowners planning an extension or renovation to a landed house assume the process works the way it would for repainting a room or redoing a kitchen: pick a contractor, agree on a price, start work. An A&A project, additions and alterations to an existing house, doesn't actually work that way in Singapore. Before a single wall comes down, someone has to formally submit the plans to the relevant authority and put their own professional registration behind them. Skipping that step isn't a shortcut; it's the reason some A&A projects stall for months before they ever reach the construction stage.
An Architecture Company Is Doing More Than Design Work on an A&A Project
Hiring an architecture company in Singapore for an A&A job isn't just about getting a nicer floor plan. For additions and alterations to a landed house, the plans have to be lodged with the authorities by a Qualified Person, specifically a registered architect or professional engineer, who is also appointed to the project and personally endorses what gets submitted. That endorsement is what allows construction to legally begin at all, regardless of how good the design looks on paper.
This is also where separating the design firm from the construction firm tends to create friction. If the architect who drew the plans isn't managing the build, a change made on site has to loop back through someone who wasn't there when the decision was made.
The Term 'A&A Contractor' Hides an Extra Legal Step Most People Don't Expect
Describing someone as an A&A contractor makes the work sound like a construction job, full stop. In practice, most A&A proposals for a landed house also have to meet planning guidelines before they can even be lodged, including limits on how much floor area can be added and how much of the existing structure has to be kept. None of that is something a contractor decides on site.
Three A&A Thresholds Worth Knowing Before Anything Gets Drawn Up
Added gross floor area generally can't exceed 50% of the home's existing and approved GFA
Replacing external walls is capped at 50% of the existing external walls under the same guidelines
Structural changes to the floor area are similarly limited to 50% of the existing and approved floor area
Finding an A&A Contractor in Singapore Who's Also the Qualified Person
This is the practical argument for looking at an A&A contractor in Singapore that operates as a single, integrated appointment rather than two separate ones. When the firm managing construction is the same one that holds the Qualified Person endorsement, a change discovered mid-build, a pipe in an unexpected place, a beam that needs rerouting, can be resolved by the person who already understands the full context of the approved plans, rather than routed through a third party who has to be briefed from scratch.
Does Every A&A Job Actually Need This Level of Sign-Off?
Not every change to a house counts as A&A work requiring full plan lodgment. Minor, low-risk works that don't affect structure, fire safety, or essential building elements are generally treated as insignificant building works and don't require the same submission. The difficulty is that this distinction isn't always obvious from the outside; a change that looks cosmetic can still touch something structural, which is precisely why it's worth having a Qualified Person assess the scope before assuming a project falls into the simpler category.
This also explains why two homes undergoing what look like similar renovations can end up on very different timelines. One owner's plan might sit comfortably within the insignificant-works category and proceed almost immediately, while a neighbour's near-identical-looking request turns out to touch a load-bearing wall or push floor area past the 50% threshold, and suddenly needs full lodgment, a Qualified Person's endorsement, and a waiting period before any work can start. Neither homeowner necessarily did anything wrong; the difference usually comes down to details that were never visible from the street.
None of this is meant to make a landed house renovation sound more complicated than it needs to be. It's meant to explain why the paperwork stage isn't a formality tacked onto the start of the project; it's the stage that actually determines what can be built, and who's legally allowed to say so. A scope that gets assessed properly before design work begins tends to move faster overall, precisely because nobody discovers a missing approval halfway through construction.
Working out what your home's A&A limits actually allow starts with one conversation. Contact Meridian Homes to find out what's possible before the design work even begins.
