SINGAPORE, July 6 — Boutique private residential developments with fewer than 50 units are significantly more likely to register poor construction workmanship compared with larger projects, according to new data from the Building and Construction Authority (BCA).

The Straits Times reported that small condominiums made up over 58 per cent of private residential projects that received low band ratings under the Construction Quality Assessment System (Conquas) over the past six years. Of 167 projects assessed, 48 were rated in bands 4 to 6 — the lowest tiers — and 28 of these were boutique developments.

Conquas evaluates workmanship and major defects such as water seepage, cracked tiles and broken fittings. BCA also assigns band ratings to developers and builders. Fewer than one in every 1,000 units built by a band 1 developer had major defects reported after temporary occupation permit (TOP), compared with 80 in every 1,000 units for band 6 developers.

The authority said developers that deliver projects with severe non‑compliances affecting safety, or those with consecutive projects showing major defects, may be barred from participating in land sales for up to five years under the Land Sales Disqualification Framework introduced on May 22.

Several boutique projects that marketed themselves as luxury homes were among those with weaker scores. These included The Carrara in Mountbatten Road, which received a band 5 rating, and 33 Devonshire, a 21‑unit condo developed by Sekon International, also rated band 5.

Industry experts told ST that smaller projects tend to rely more heavily on onsite construction — such as formwork, concrete pouring and installation — which is more vulnerable to weather conditions and workmanship variability. Larger developments, by contrast, often use prefabricated systems produced under controlled factory conditions and attract more experienced contractors.

Despite the use of premium materials in some boutique projects, poor installation can still lead to high defect rates and lower Conquas scores, experts said.

BCA’s inspections and validated feedback from homeowners after TOP contribute to the banding of each project. The authority said the strengthened framework aims to deter errant developer behaviour and provide greater protection for home buyers.