What's the difference between new erection, reconstruction and a&A for your landed home?

This is a significant decision for any landed homeowner in Singapore. The difference between these three categories affects not just your budget and timeline, but also how much "usable space" you can legally build and whether you need to comply with the latest (and sometimes stricter) building codes.

Here is a simplified guide tailored for prospective clients.

The Landed Homeowner’s Dilemma: A&A, Reconstruction, or New Erection?

If you own a landed property in Singapore, you possess a rare asset with immense potential. But when it comes to upgrading that asset, you are faced with a regulatory fork in the road.

The Urban Redevelopment Authority (URA) classifies development works into three distinct tiers. Knowing which tier your dream home falls into is the first step to avoiding costly compliance surprises.

1. Additions & Alterations (A&A)

Think of this as: A Major Facelift.

Best for: Homeowners who are generally happy with the existing size and shape of the house but want to modernize the interior, change the layout, or add small extensions.

The "50% Rule"

To qualify as A&A, your project must retain more than 50% of the existing:

• GFA (Gross Floor Area): You cannot double the size of your house.

• Structural Elements: Columns, beams, and floor slabs.¹

• External Walls: You cannot tear down most of the facade.²

  
  

The Limitations:

• No New Storeys: You generally cannot add a completely new floor (e.g., turning a 2-storey house into a 3-storey house). You can usually add an attic if the envelope permits, but a full new storey triggers "Reconstruction."

• Same Housing Form: You cannot change a Semi-Detached into a Detached Bungalow.

  
  

The Pros:

• Faster: Approvals are simpler; construction is shorter.³

• Cheaper: You save on heavy structural works and piling.

• Less Red Tape: You may be exempt from building a Household Shelter (Bomb Shelter) if you aren't touching the existing one.⁴

  
  

2. Reconstruction

Think of this as: A Structural Overhaul.

Best for: Owners who want to drastically increase floor area (e.g., adding a new floor) but want to save some costs by keeping parts of the old structure (like the foundation or some walls).

The Triggers

A project moves from A&A to Reconstruction if ANY of the following happens:

1. Exceeds 50%: You replace more than 50% of the GFA, structural elements, or external walls.

2. Storey Increase: You add a new storey (regardless of how little other work you do).

3. Form Change: You change the housing form (e.g., Terrace to Semi-D).

   
   

The "Catch":

Once you trigger Reconstruction, slightly more stringent URA regulations apply.

• Envelope Control: The entire house must fit within the modern "Envelope Control" guidelines (see below).

• Household Shelter: A new Household Shelter must be provided in line with BCA's regulations, unless BCA grants a special exemption waiver.

• Setbacks: You may be forced to push walls back to meet current setback requirements, which might be stricter than when the house was originally built.⁵

• Car Porch: Your car porch width and length must meet current standards.

• Structural Complications: If you intend to add another storey or extension, additional structures like columns and beams, and potentially new foundations need to be put in place. These new structures have to be designed to fit within the limitations of the existing structural positions, creating a layer of complexity which will incur cost.

  
  

3. New Erection

Think of this as: The Blank Slate.

Best for: Old single-storey houses, plots with structural issues, or owners who want a completely modern design with zero compromises.

The Definition:

You demolish the existing house entirely and build a new one from scratch.

The Pros:

• Design Freedom: You are not limited by existing columns or awkward layouts.⁶ You can maximize the plot's potential (GFA) fully.

• Longevity: You get a brand new foundation, waterproofing, and M&E systems, reducing maintenance for decades.

• Value: Generally commands the highest resale value as buyers view it as a "brand new" asset.

  
  

The Cons:

• Cost: Likely the most expensive option (demolition + piling + construction).

• Timeline: Expect 18–24 months (or longer) from design to handover.

• Mandatory Shelter: You must build a Household Shelter (HS) according to BCA regulations.

Summary Comparison Table

Feature	Additions & Alterations (A&A)	Reconstruction	New Erection
Existing Structure	Retain > 50%	Retain < 50% (or add storey)	Demolish 100%
New Storey?	No	Yes	Yes
Envelope Control	Existing bulk generally respected	Must comply fully	Must comply fully
Household Shelter	Usually not required	Subject to assessment	Mandatory
Est. Timeline	9 - 12 Months	12 - 18 Months	18 - 24+ Months
Cost	$	$$	$$$

A Critical Note: The "Envelope Control" Guidelines

If you choose Reconstruction or New Erection, your design is governed by the "Envelope Control" guidelines.⁷

• Old Rule: Boxy constraints based on plot ratio.

• Current Rule: A volumetric approach. URA defines a 3D "envelope" based on setbacks and overall height (e.g., 12m for 2-storey zones, 15.5m for 3-storey zones).⁸

• The Opportunity: This allows for more creative designs—mezzanine floors, higher ceilings, and varied roof shapes—as long as the house fits inside the invisible "cookie cutter" shape over your land.⁹

URA's envelope control for two and three-storey landed houses. Under the new guidelines, landed home designs should fit within these building envelope.

Which path is right for you?

• Choose A&A if: Your house is structurally sound, and you just want a modern look or a bigger kitchen.

• Choose Reconstruction if: You need an extra floor (e.g., for a growing family) but want to save money on piling/foundation works.

• Choose New Erection if: The existing house is very old (pre-1990s), has dampness/termite issues, or sits on a plot where the current house is tiny compared to what the land could support.

Next StepS

Reach out to us at hello@quarters.sg if you'd like to find out more about the documents you will need to prepare (e.g., topographical surveys, soil tests) and the process of engaging an architect and consultants for your new home.