New-Build Snagging and Decoration in London: Beyond the Developer Finish

The Reality of a Developer Finish

New-build properties in London are handed over to buyers with a "developer finish" that is presented as complete decoration. In practice, what this usually means is a single coat of trade emulsion applied directly to the plasterboard skim, white throughout, with white gloss or satinwood on woodwork. It is a finish designed to satisfy building control and the sales brochure, not one designed to last or to look its best.

Understanding what you have been handed, and what it will take to bring it up to a finish you are genuinely happy with, is the starting point for any new-build decoration project. This is especially relevant in London, where new-build flats are frequently selling for significant sums and the occupants' expectations of finish quality are correspondingly high.

Why New Plaster Must Have a Mist Coat

New plasterwork — whether traditional multifinish skim or plasterboard — is highly porous and alkaline when fresh. Applying emulsion directly to it without a mist coat causes the emulsion to dry unevenly, typically resulting in a patchy finish where some areas have soaked into the plaster more than others. This is often visible as light and dark patches in the dried surface.

A mist coat is simply the finish emulsion diluted with water — typically 10% water added to the paint — and applied as a diluted first coat. This seals the surface evenly and allows the subsequent full-strength coats to go on consistently. Some manufacturers now sell purpose-made mist coat primers (Dulux Trade Plaster Sealer, for example), which are convenient but no more effective than a properly diluted coat of the finish paint.

Many London developers apply their single coat of emulsion without a proper mist coat stage, or apply the emulsion before the plaster has fully dried. Both shortcuts result in a finish that feels complete but has poor adhesion and will begin to show problems — flaking patches, poor adhesion at edges and around switches — within twelve to eighteen months.

Snagging: What to Look For Before Decoration

If you are taking on a new-build property and planning to redecorate, carry out a thorough snagging inspection of the walls and ceilings before any work begins. This is the moment to identify issues that are properly the developer's responsibility to address, and to raise them formally before the snagging period closes.

Common defects to look for:

Nail pops — where plasterboard fixings push through the plaster surface as the timber frame settles and dries. They appear as small circular protrusions on wall and ceiling surfaces. They are usually easy to fix (push back, fill, sand), but they should be noted.

Joint shadows — visible as slight ridges or hollows running in straight lines across walls or ceilings, corresponding to the taped joints between plasterboard sheets. They are often invisible in flat light but show clearly under a raking lamp or strong natural sidelight. Joint shadows require filling and feathering to disappear.

Skim irregularity — plasterboard skim applied by volume rather than by skill often has visible tool marks, ridges, or areas where the surface is not truly flat. Check with a long straightedge (a 2m aluminium level works well).

Window reveals and sills — frequently rushed in a volume new-build programme. Check that reveals are square, that sills are fully painted and caulked at junctions, and that any exposed plasterboard edges are properly skimmed.

Ironmongery and frame paint — door frames are often painted with the door closed, leaving unpainted strips at the rebate and in the frame angles. Hinges are frequently paint-contaminated.

Upgrading the Finish: The Correct Sequence

Once snagging is completed and any developer remediation is done, the upgrade sequence for a new-build flat is straightforward but must not be rushed:

1. Allow plaster to cure — new plaster needs a minimum of six to eight weeks to cure before applying a full decorating system; longer in basements or poorly ventilated spaces.
2. Fill and sand — address nail pops, joint shadows, tool marks, and any surface irregularities using fine surface filler (Toupret Fibacryl or Polycell Fine Surface) and 120–180 grit sandpaper.
3. Mist coat — diluted emulsion applied to all wall and ceiling surfaces.
4. Two full coats of finish emulsion — at the correct coverage rate (do not over-extend).
5. Strip and re-coat woodwork — if the developer gloss or satinwood is sound, sand back, apply a coat of Zinsser BIN or a compatible adhesion primer if switching to water-based, and apply two coats of chosen finish. If the woodwork is marked, dented, or poorly applied, strip and start from bare.
6. Caulk all junctions — around skirting, architrave, window reveals, and cornices. New-build properties settle significantly in the first year, and caulked junctions need re-doing after the first heating season.

Realistic Cost Expectations

In London, a two-bedroom new-build flat with two reception rooms, kitchen, and two bathrooms will typically require two to three days of professional preparation and decoration to bring it to a proper finish from a developer white. Material costs are additional. For a premium finish with higher specification products (Little Greene, Farrow and Ball) and multiple colours, allow more time.

The cost of doing this properly, once, shortly after handover, is significantly less than the cost of redoing it in two years when the developer finish begins to fail.

For a survey and quotation on your new-build property in London, contact us or request a free quote.