Historical Context and Manufacturing

The Lowton-Cubitt house, a hallmark of mid-20th century British architecture, stands as a testament to the ingenuity and adaptability of post-war construction methods. Manufactured between 1964 and the 1970s, these properties were the brainchild of Cubitts Construction Systems Ltd and Lowton-Cubitt Housing Ltd, with design input from the Lowton Construction Group. During this period, approximately 3,700 units were built, primarily in urban and suburban areas across the UK. These homes were also known by alternative names such as Cubitt, LC, LC System, and Modulow.

The primary aim behind the Lowton-Cubitt house was to address the housing shortage in the UK by providing affordable, quickly constructed homes. The use of system-built methods allowed for rapid assembly and reduced costs, making homeownership more accessible to a broader segment of the population.

Identification Characteristics

Recognising a Lowton-Cubitt house is relatively straightforward once you know what to look for. These properties are typically two-storey terraced houses, although some variants include integral garages and utility rooms on the ground floor, giving the appearance of a three-storey house. The medium pitch gable roof, covered with interlocking concrete tiles, is a distinctive feature.

External walls may be clad in tile hanging, PVC shiplap boarding, or render, with brick panels at the separating wall. The gable wall is usually constructed of brick throughout or features mathematical tiles up to the eaves level, with vertical timber boarding at the apex. Brick or mathematical tiles often return around the front and rear walls, adding to the unique aesthetic of these homes.

Construction Details

Substructure

The substructure of a Lowton-Cubitt house typically consists of a concrete trench foundation, rebated externally, with a damp-proof course (DPC) to prevent moisture ingress. This robust foundation provides a stable base for the structure above.

Frame

The main frame comprises 2′ 0″ and 2′ 4″ welded rolled steel channel (RSC) frames, RS hollow box stanchions, RSA perimeter beams, and additional RSC perimeter beams. The steel frame is protected with a red oxide paint and a site-applied black bituminous paint to prevent corrosion.

External Walls

The front and rear walls are constructed using a combination of brick panels, cavity walls, gas concrete panels at the separating wall, and timber frame infill panels clad with tile hanging. These walls are lined with insulation board and plasterboard for thermal efficiency. The gable wall features a similar construction, with brick and gas concrete panels returned around the front and rear walls.

Separating Wall

The separating wall between terraced houses is a gas concrete panel cavity wall, with blocks in the roof space sealed at eaves level to prevent fire spread and improve sound insulation.

Partitions

Internal partitions on the ground floor are timber stud walls lined with plasterboard, while the first floor features honeycomb plasterboard partitions. This construction method provides a balance between structural integrity and ease of installation.

Floors

The ground floor is typically a concrete slab, providing a durable and stable surface. The first floor consists of chipboard on timber joists, offering a lightweight yet strong flooring solution.

Ceilings

Ceilings throughout the property are lined with plasterboard, providing a smooth, paintable surface that can be easily repaired if damaged.

Roof

The roof structure comprises timber trusses, bituminous felt, and interlocking concrete tiles. The trusses are lined with sheathing at the gable wall to enhance structural stability and weather resistance.

Typical Hazards and Risks

While the Lowton-Cubitt house was a revolutionary design for its time, it is not without its potential hazards and risks. Understanding these issues is crucial for prospective buyers and investors.

Corrosion

One of the most common issues with Lowton-Cubitt houses is the minor to moderate corrosion of the RSC frame and RS hollow box stanchions, particularly at external wall bases located below the DPC. This corrosion can compromise the structural integrity of the property if not addressed promptly.

Holding Down Bolts

Damaged, loose, or missing holding down bolts are another concern. These bolts are essential for securing the steel frame to the foundation, and any deficiencies can lead to structural instability.

Cracking

Vertical and horizontal cracking of gas concrete panels, especially in the separating wall, is a frequent issue. These cracks can allow moisture ingress, leading to further deterioration of the structure and potential mould growth.

Rain Penetration

Rain penetration at infill panel-brick joints is a common problem, particularly in older properties where the original sealant may have degraded. This can lead to damp issues and damage to internal finishes.

Defective Premises Act

The Lowton-Cubitt house is not classed as defective under the Defective Premises Act. However, it is essential to be aware of the potential issues and address them promptly to maintain the property’s structural integrity and value.

Inspection Guide for Surveyors

When inspecting a Lowton-Cubitt house, surveyors should pay close attention to several key areas to identify potential issues and assess the overall condition of the property.

External Inspection

1. Roof: Check for missing or damaged interlocking concrete tiles and inspect the condition of the bituminous felt. Look for signs of sagging or unevenness in the roofline, which could indicate issues with the timber trusses.

2. Walls: Examine the external walls for signs of cracking, particularly at the infill panel-brick joints. Check the condition of the tile hanging, PVC shiplap boarding, or render, and look for any areas of damage or deterioration.

3. Gable Wall: Inspect the gable wall for signs of cracking or movement. Check the condition of the mathematical tiles and vertical timber boarding at the apex.

4. Foundation: Look for signs of settlement or movement in the foundation. Check for any visible cracks or gaps around the base of the external walls.

Internal Inspection

1. Frame: Inspect the steel frame for signs of corrosion, particularly at the bases of the external walls. Check the condition of the protective coatings and look for any areas where the paint has flaked or peeled away.

2. Holding Down Bolts: Check the condition of the holding down bolts and ensure they are secure. Look for any signs of damage or corrosion.

3. Walls: Examine the internal walls for signs of cracking, particularly in the gas concrete panels. Check for any signs of moisture ingress or dampness.

4. Floors: Inspect the condition of the concrete ground floor and the chipboard first floor. Look for any signs of movement or unevenness, which could indicate issues with the timber joists.

5. Ceilings: Check the condition of the plasterboard ceilings and look for any signs of sagging or cracking. Inspect the roof space for signs of water ingress or damage to the timber trusses.

Typical Defects and Maintenance

Understanding the typical defects associated with Lowton-Cubitt houses can help homeowners and investors plan for necessary maintenance and repairs.

Corrosion of Steel Frame

As mentioned earlier, corrosion of the steel frame is a common issue. Regular inspections and maintenance of the protective coatings can help prevent this problem. If corrosion is detected, it should be addressed promptly to prevent further deterioration.

Cracking of Gas Concrete Panels

Cracking in the gas concrete panels can be addressed by sealing the cracks with a suitable filler and applying a waterproof coating to prevent moisture ingress. In severe cases, it may be necessary to replace the affected panels.

Rain Penetration

To address rain penetration at infill panel-brick joints, the original sealant should be replaced with a high-quality, weather-resistant sealant. Regular inspections and maintenance of the external walls can help prevent this issue.

Holding Down Bolts

Damaged or loose holding down bolts should be replaced or tightened as necessary. Regular inspections can help identify any issues before they become serious.

Variants and Modifications

Over the years, several variants and modifications of the Lowton-Cubitt house have been developed to address some of the original design’s shortcomings and adapt to changing building regulations and standards.

Concrete Pads and PRC Ground Beams

Some variants feature concrete pads and pre-cast reinforced concrete (PRC) ground beams instead of the traditional concrete trench foundation. This modification provides additional stability and can help address issues with settlement or movement.

Steel Frame Variations

In some variants, all steel frames are 2′ 0″ wide, and additional RS hollow box stanchions are used. The siting of the steel frames may vary, with different frame layouts used to suit specific site conditions or design requirements.

Cladding Variations

Some Lowton-Cubitt houses feature mathematical tile cladding at the separating and gable walls, returned around the front and rear walls. The gable apex may be clad with vertical timber boarding, and chipboard may be used on the external face of the steel frames.

Insulation and Lining

Variants may include timber stud frames with glass fibre insulation, lined with plasterboard, to improve thermal efficiency. PVC shiplap boarding or render may be used on the front and rear infill panels.

Flooring Variations

In some variants, chipboard is used on timber joists at the ground floor, providing a lightweight and cost-effective flooring solution.

Roof Variations

The roof structure may feature trussed timber or plywood webbed purlins, providing additional strength and stability. Some variants include gas concrete panels extending to the roofline for improved fire resistance and sound insulation.

Integral Garages and Utility Rooms

Some Lowton-Cubitt houses include integral garages and utility rooms on the ground floor, forming a three-storey house. In these variants, there is no steelwork at the ground floor level, with the garage and utility room constructed using brick.

Conclusion

The Lowton-Cubitt house remains a significant part of the UK’s architectural heritage, offering a unique blend of affordability, rapid construction, and distinctive design. While these properties are not without their challenges, understanding the typical hazards and risks, as well as the necessary maintenance and repairs, can help homeowners and investors make informed decisions.

At Flettons, we’re committed to safeguarding your investment. When considering a property purchase, trust our seasoned expertise to reveal any hidden threats. For a thorough building survey, get your instant quote through our quote calculator or reach out directly at 0203 691 0451. Your home’s safety is our top priority.

---