Understanding the Symplex House

The Symplex house, a notable example of system-built properties in the UK, represents a unique chapter in the history of British housing. Constructed primarily in 1965, these homes were the brainchild of manufacturers C Cornes & Sons Ltd and Cussins Ltd, with design input from Forshaw, Greaves & Partners. Known by various names such as Cornes, Cornes Cussins, and Cussins Cornes, these properties are predominantly found in semi-detached and terraced forms. This article delves into the intricate details of the Symplex house, offering insights into its construction, typical characteristics, potential hazards, and inspection tips for prospective buyers and investors.

Historical Context and Manufacturing Details

The Symplex house emerged during a period when the UK was exploring innovative construction methods to address housing shortages. The year 1965 marked the peak of this architectural experiment, with a significant number of these homes being built across the country. The collaboration between C Cornes & Sons Ltd and Cussins Ltd, alongside the design expertise of Forshaw, Greaves & Partners, resulted in a distinctive housing style that combined practicality with modernity.

Architectural Characteristics

Symplex houses are easily identifiable by their two-storey structure, often featuring a shallow pitch gable roof or a flat roof. These roofs are typically covered with plastic roof sheets or interlocking concrete tiles. The front and rear external walls are constructed from storey-height timber frame panels, incorporating doors and windows, and are clad with shiplap boarding and tile-faced precast concrete (PC) panels. The gable walls are consistently clad with tile-faced PC panels, providing a uniform aesthetic.

Construction Details

The construction of Symplex houses is a testament to the innovative use of materials and techniques during the 1960s. The substructure consists of concrete pads below stanchions and a concrete slab thickened around the perimeter, with a damp-proof course (DPC) to prevent moisture ingress. The main frame comprises eight rolled steel channel (RSC) stanchions, perimeter beams, floor support beams, ceiling support beams, and roof trusses, all connected using Kariscol joints. These components are protected with a chromium plumbate paint coating to enhance durability.

The external walls feature a combination of timber frame panels, shiplap boarding, and tile-faced PC panels, with a cavity filled with Stramit boards for insulation. The separating walls are concrete lined with plasterboard, while internal partitions use Stramit (strawboard) boarding. The ground floor is typically concrete, with the first floor constructed from chipboard on timber joists. Ceilings are finished with plasterboard, and the roof comprises timber purlins, flaxboard, and Duraform plastic sheets.

Variants and Modifications

Over the years, some Symplex houses have undergone modifications to suit modern living standards. Variants include suspended ground floors made of chipboard or plywood on timber joists, first floors of plywood on timber joists, and interlocking concrete tile roof covers. Some properties may also feature flat roofs, offering a different aesthetic and functional appeal.

Potential Hazards and Risks

While Symplex houses offer unique architectural features, they are not without potential hazards and risks. One of the primary concerns is the presence of asbestos in some construction materials, which poses health risks if disturbed. Additionally, the timber frame construction may be susceptible to rot and insect infestation if not properly maintained. The use of Stramit boards, a straw-based material, can also present fire hazards if not adequately protected.

Defective Premises Act Considerations

Under the Defective Premises Act, properties must be fit for habitation and free from significant defects. While Symplex houses are not inherently classified as defective, potential buyers should be aware of the specific risks associated with this property type. A thorough inspection by a qualified surveyor is essential to identify any issues that may affect the property’s safety and value.

Inspection Tips for Symplex Houses

When inspecting a Symplex house, it is crucial to focus on several key areas to ensure the property’s integrity and safety:

1. Roof and Guttering: Check for signs of wear and tear on the roof, including missing or damaged tiles and leaks. Inspect the guttering for blockages and ensure proper drainage.

2. External Walls: Examine the cladding for cracks, warping, or signs of water ingress. Pay attention to the condition of the shiplap boarding and tile-faced PC panels.

3. Timber Frame: Look for signs of rot, insect damage, or structural weakness in the timber frame. Ensure that any protective coatings are intact and effective.

4. Insulation and Ventilation: Assess the condition of the Stramit boards and ensure adequate insulation and ventilation to prevent moisture buildup and potential fire hazards.

5. Internal Partitions and Ceilings: Check for cracks, dampness, or signs of movement in the internal partitions and ceilings. Ensure that plasterboard finishes are secure and free from damage.

6. Floors: Inspect the ground and first floors for signs of sagging, unevenness, or damage. Pay attention to the condition of chipboard or plywood flooring and timber joists.

7. Asbestos: If asbestos is suspected, seek professional advice and testing to determine its presence and condition. Avoid disturbing any materials that may contain asbestos.

Maintenance and Improvement Tips

Maintaining a Symplex house requires regular inspections and proactive measures to address potential issues. Here are some tips to help you keep your property in top condition:

• Regular Inspections: Conduct routine inspections of the roof, walls, and timber frame to identify and address any signs of wear or damage promptly.

• Moisture Control: Ensure proper ventilation and drainage to prevent moisture buildup, which can lead to rot, mold, and structural damage.

• Pest Control: Implement measures to protect the timber frame from insect infestation, such as using treated wood and sealing entry points.

• Fire Safety: Enhance fire safety by installing smoke detectors, fire-resistant materials, and ensuring clear escape routes.

• Energy Efficiency: Consider upgrading insulation, windows, and heating systems to improve energy efficiency and reduce utility costs.

Conclusion

The Symplex house represents a fascinating blend of mid-20th-century innovation and architectural design. While these properties offer unique features and historical significance, they also present specific challenges and risks that require careful consideration. By understanding the construction details, potential hazards, and maintenance requirements, prospective buyers and investors can make informed decisions and ensure the long-term safety and value of their investment.

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.

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