A&A Works

Ask each firm who will do the jobs the rules require, and get names. Which registered architect or professional engineer will be your Qualified Person, and do they hold a valid practising certificate? Which civil or structural engineer will sign and submit the structural plans? Which builder will be on BCA's permit application for the structural work? Then ask who supervises the site day to day, and how anything found when a ceiling or floor is opened up gets priced and approved before work carries on. A Qualified Person must be registered with the Board of Architects or the Professional Engineers Board and hold a valid practising certificate, and only one who is a professional engineer in the civil or structural discipline can apply for structural plan approval. DirectHome takes on A&A works for landed houses as the principal contractor. To start, send photos of the house, the approved plans if you have them, and what the house is missing, such as a bedroom downstairs or a bigger kitchen.

Renovation is the everyday word for doing up a house. In planning terms, A&A means adding to or altering an existing landed house within URA's limits. URA's guideline on additions and alterations to landed housing, which reads the same in its terrace, semi-detached and bungalow handbooks, keeps a proposal within A&A only if the floor area added is no more than 50% of the approved floor area, the outside walls taken down and replaced are no more than 50% of the approved outside walls, structural changes such as new columns and beams or rebuilt floor slabs are no more than 50% of the existing building, a whole new roof doesn't add a storey, and an attic adds less than 50% to the floor area. Anything outside those limits is reconstruction, and so is any extra storey or a change of house type, such as a semi-detached house becoming a detached one, whatever the percentages. A house approved under older rules has to keep new A&A within today's permissible building envelope, the outline URA allows the house to be built within, and if it's already bigger than that envelope, the A&A can't add to its bulk. Ask your Qualified Person to check the design against these criteria before it's priced. The A&A works buying guide goes further into choosing between a replan, an extension and a rebuild.

Look at three things. First, the state of the structure you'd keep, because A&A keeps the existing beams, columns and foundations and they have to carry the new work. Second, how much of the house your new layout would take out. If it means removing most of the walls and floors anyway, it crosses URA's 50% limits and becomes reconstruction. Third, whether your plot allows a bigger house than A&A's limit on added floor area would give you. Parts of an older house that were approved but wouldn't be allowed today can sometimes be kept. URA may consider it, under A&A or reconstruction, only if at least 25% of the existing floor plate is kept as one connected wing of columns, beams, floor slab and outside walls that includes those parts, a Professional Engineer certifies that what's kept is sound and can take the new works, and a front setback that's short of today's rules still leaves at least 2.4 m to the front boundary. If any of those kept parts is later demolished, URA has to be told at once, and the Qualified Person must make an amendment application before new works go on site. Replanning, extending or rebuilding for an extra bedroom compares the three against the same need.

We can't point you to a current independent price for A&A works in Singapore, so here's what makes one job bigger than another. An extension needs new footings beside the old foundations. On a middle terrace reached only through one narrow front, materials and rubble have to pass through the house itself, which is slower and dearer than working on a detached plot a lorry can drive into. Where the new roof meets the old one, the old roof is opened up and waterproofed again. A drain in the way may need moving. The room the extension opens into is hacked and then made good. And the Qualified Person's and engineer's design and submissions come before any of it is built. Which of these costs most varies from house to house, so no single part is the most expensive on every job. If you're weighing a rebuild instead, a June 2024 DollarsAndSense guide put building a landed house at S$300 to S$500 per square foot of built-up area, and about S$1.5 million for rebuilding a simple 3,000 sq ft house including professional fees. That's its estimate for a whole new house, not a price for adding to one.

Only if it covers everything the extension needs, not just the new room. On a landed extension that means the Qualified Person's and engineer's design and submissions, the foundations and structure, joining the new roof and drains to the old house, the finishes, and making good the room the extension opens into. Share your ceiling at the start so the design team can compare a smaller extension with reworking the rooms you already have, such as taking out a wall to join two rooms, before anything is drawn in detail.

Possibly. A corner terrace differs from a middle unit in two ways. It shares a wall with only one neighbour, and its side faces a boundary rather than another house. What decides a rear extension is the building setback from the rear boundary, any drain running behind the house, and the daylight left in the middle of the house once a new room sits in front of the back windows. URA's controls for each plot include building setbacks, so ask your Qualified Person to check the rear and side setbacks for your plot before the extension is sized. Where the work touches the shared wall, remember that wall holds up two houses, so cutting into it or putting new load on it affects next door too and needs the engineer's design.

The common choices are a flat concrete roof, a pitched tiled roof and a metal roof, and each changes the room below and the old house differently. A flat concrete slab is the heaviest, so the structure under it has to carry that weight, and it soaks up the day's heat and gives it off into the evening. It also needs a waterproofing layer and a fall to its outlets so water doesn't pond. A pitched tiled roof sheds rain quickly, but its slope has to meet the old house without trapping water where the two join. A metal roof is the lightest, but it's louder in heavy rain and heats up fast unless it's insulated underneath. Whichever you choose, ask which gutter and drain the new roof's water runs to and how it joins the existing roof. Why flat and pitched roofs leak in different places explains the difference, and if you want rooflights, keeping a room under the roof cool covers glazing, shading and heat together.

We can't give you a number of weeks until the design is drawn and the structure has been checked, so get the programme in writing at that point. The approvals come before structural work. Where a design meets URA's plan lodgment criteria for A&A to a landed house, a Qualified Person can lodge it and URA issues an acknowledgement letter, valid for two years. BCA's targets for processing a complete structural plan application are 7 working days without an accredited checker's certificate, 10 days for a first submission and 14 working days for later ones with one, and 20 working days under CORENET X. The permit to carry out structural works has a target of 7 working days and can be applied for together with the plans. Plans that need more evaluation, or that come from a Qualified Person whose past submissions were poor, can take longer. These are targets for complete applications, not a project schedule, and the design, URA's side, the building work and anything found once the structure is opened up all add time. Some minor jobs are insignificant building works that need no plan submission to BCA, though approvals from other authorities can still apply.

You can stay only if the part of the house you're living in keeps a safe way in and out, a working bathroom, water and power, and is sealed off from the dust and the work. Work on the roof, the stairs, the only bathroom or the pipes can take one of those away for a stage, so get the order of work in writing and decide stage by stage whether everyone stays, moves to another floor or moves out. Living at home during A&A works goes through what to check at each stage.