Uniment Houses

Uniment houses are a relatively rare form of system-built property constructed primarily in the 1940s by Uniment (France) Ltd. Only about 40 were built, and they are most commonly seen in semi-detached and terraced form.

These houses were developed in the post-war period when rapid construction methods were being used to address housing shortages. They were designed for speed of assembly and relied extensively on pre-cast concrete components.

A Uniment house showing the rendered external walls and steep pitch gable roof associated with this 1940s system-built form.

Uniment houses are usually found in urban and suburban areas across the UK, although they remain uncommon. The external walls are rendered throughout, and some examples include eaves height gable bays, dormer windows above first-floor level, and cantilevered flat PC canopies over the front doors.

Internally, the ground floor is generally of concrete construction, while first floors are commonly formed with timber joists. The roof structure usually comprises timber rafters and purlins supporting a tiled roof, although some variants are understood to have used PC floor slabs and PC trusses.

The substructure comprises a concrete slab with a damp-proof course. External walls use 12-inch square hollow PC columns with a V rebate to receive the ends of PC panels infilled with reinforced concrete. The rendered walling includes clinker PRC panel cavity walls reinforced with chicken mesh and/or mild steel bars, with the cavity filled with clinker aggregate concrete. Separating walls are also of clinker PRC panel cavity construction, while internal partitions are built in clinker concrete blockwork.

Vertical cracking of the render is a recognised issue, particularly at junctions between PC columns and clinker PRC panels. This sort of cracking needs careful assessment because it can reflect movement, differential behaviour between materials, or local deterioration within the wall construction.

Water penetration through the external walls is another established concern. Once moisture gets through the rendered envelope, dampness can affect internal finishes and contribute to longer-term deterioration of embedded reinforcement or adjacent timber elements.

The wall reinforcement itself is a further point of risk. Chicken mesh and mild steel bars can corrode over time, especially where concrete cover is limited or the property has been exposed to persistent damp conditions. Where corrosion develops, cracking and local breakdown of the surrounding material can follow.

Timber decay also needs to be considered, particularly in roof timbers and first-floor timber elements where there has been water ingress or poor ventilation. The condition of the tiled roof, dormers where present, and the cantilevered flat PC canopies should be given proper attention during inspection.

A Uniment house is a non-traditional purchase and is best approached with a clear understanding of its system-built construction. The construction is unusual, the housing type is rare, and inspection needs to focus on the actual condition of the rendered walling, reinforcement, and timber elements rather than relying on appearance alone.

It is sensible to look closely at the condition of the render, any evidence of dampness, the roof structure, the concrete ground floor, the first-floor timber joists, and any cracking or movement to walls and partitions. The limited documentation noted in relation to ceiling construction also makes on-site inspection especially important.

Uniment houses are not specifically listed under the Defective Premises Act. Even so, significant defects affecting safety or habitability would still need to be addressed, and the outcome of a survey is likely to be important where notable cracking, dampness, corrosion, or timber deterioration is found.

For any non-traditional property, clarity over construction and condition matters. Where defects are visible, further assessment or remedial work may be necessary to establish whether the property meets the standard expected for continued occupation and ongoing maintenance.

A building survey provides an informed assessment of the visible condition and construction of a Uniment house. Inspections are non-intrusive and limited to areas that are accessible at the time of inspection.

• Identify visible cracking to rendered wall surfaces and at junctions between PC columns and clinker PRC panels
• Assess signs of dampness, moisture ingress, and water penetration through external walls
• Comment on the condition of tiled roof coverings, timber rafters, purlins, dormers, and PC canopies where present
• Review the general condition of accessible floors, ceilings, walls, partitions, and structural elements
• Highlight defects that may require repair, monitoring, or further investigation

However, there are limitations to what a survey can determine without intrusive investigation.

• Confirm the full condition of concealed reinforcement such as chicken mesh or mild steel bars within the wall construction
• Assess hidden structural elements behind finishes, renders, or linings
• Determine the full extent of corrosion, internal deterioration, or decay within inaccessible parts of the structure
• Inspect areas that are inaccessible or covered at the time of inspection

Where higher-risk indicators are identified, further specialist or intrusive investigation may be recommended.

For a thorough building survey in Greater London, an instant quotation can be obtained through the online survey calculator.