Historical Context and Background

The Formula house, a distinctive type of system-built property, emerged during the mid-1960s, specifically between 1966 and 1967. This period marked a significant era in the UK’s construction industry, characterized by a surge in innovative building techniques aimed at addressing the post-war housing shortage. The Formula house was a product of this innovation, designed by Thorne and Barton in collaboration with Morrison and Partners, and manufactured by Lewis and Watters Ltd. A total of 160 units were constructed, making them a relatively rare find in today’s property market.

These properties are typically located in suburban areas, where there was a pressing need for rapid and cost-effective housing solutions. The Formula house is also known by its alternative name, the Interbuild System Building 2, reflecting its place within a broader category of system-built homes.

Identifying Characteristics

The Formula house is easily recognizable by its unique architectural features. These properties are predominantly two-storey hexagonal structures, available in detached, semi-detached, and terraced configurations. The hexagonal design is not just an aesthetic choice but also a functional one, aimed at maximizing internal space and structural stability.

External Features

• Roof: The roof is flat and covered with bituminous felt, a common material used during the period for its waterproofing properties.
• External Walls: The walls are a mix of tile hanging, coloured asbestos cement sheets, and vertical or horizontal timber boarding. Horizontal cover strips mask the junctions at the first floor and eaves levels, while vertical cover strips conceal the joints at panel junctions.

Internal Features

• Substructure: The foundation consists of a concrete ring beam and a concrete slab.
• Frame: The main frame includes six perimeter and one central tubular stanchions, twelve RSA perimeter beams, and six RSA panel supports welded to the perimeter beams at the first-floor level. The frame layout is based on a hexagon with sides measuring 12′ 4″.
• Walls: Storey-height timber frame infill panels clad with tile hanging and lined with foil-backed plasterboard. Polystyrene insulation is placed between the frame studs. The separating wall is a brick cavity wall lined with plasterboard.
• Partitions: Timber stud partitions lined with plasterboard.
• Floors: The ground floor is concrete, while the first floor consists of chipboard on timber joists.
• Ceilings: Plasterboard ceilings.
• Roof: Timber joists, insulation quilt, chipboard, and bituminous felt.

Typical Hazards and Risks

When considering the purchase of a Formula house, it is crucial to be aware of the typical hazards and risks associated with this property type. These risks can impact both the safety and the value of the property.

Asbestos

One of the most significant hazards is the presence of asbestos cement sheets in the external walls. Asbestos was commonly used in construction during the 1960s for its fire-resistant properties. However, it is now known to pose serious health risks if disturbed. Asbestos fibres can cause lung diseases, including cancer, when inhaled. Therefore, any renovation or repair work on a Formula house should be carried out with extreme caution and by professionals trained in asbestos handling.

Structural Integrity

The structural integrity of the Formula house can be compromised over time due to various factors, including weathering, poor maintenance, and the natural aging of materials. The flat roof, in particular, is prone to water ingress if the bituminous felt is not adequately maintained. Water damage can lead to rot in the timber joists and frame, weakening the overall structure.

Insulation and Energy Efficiency

The insulation in Formula houses, typically polystyrene between frame studs, may not meet modern energy efficiency standards. This can result in higher heating costs and a less comfortable living environment. Upgrading the insulation can be a costly but necessary investment to improve the property’s energy efficiency.

Defective Premises Act

The Defective Premises Act 1972 imposes a duty on builders, developers, and landlords to ensure that properties are constructed and maintained to a reasonable standard. While the Formula house is not explicitly listed as defective under this Act, the presence of asbestos and potential structural issues could render it non-compliant if not properly addressed. It is advisable to have a thorough survey conducted by a qualified professional to identify and rectify any defects.

Inspection and Assessment Guide

For prospective buyers and investors, a detailed inspection is essential to assess the condition of a Formula house. Here is a step-by-step guide to help you through the process:

Pre-Inspection Preparation

1. Research: Familiarize yourself with the history and characteristics of the Formula house. Understanding its construction and common issues will help you know what to look for during the inspection.
2. Documentation: Gather any available documentation on the property, including previous surveys, maintenance records, and renovation history.

External Inspection

1. Roof: Check the condition of the bituminous felt for signs of wear, cracks, or water pooling. Inspect the roof’s edges and joints for any gaps or damage.
2. Walls: Examine the external walls for cracks, loose tiles, or damaged asbestos cement sheets. Look for signs of water ingress or dampness.
3. Windows and Doors: Ensure that all windows and doors are properly sealed and functional. Check for any signs of rot or damage to the frames.

Internal Inspection

1. Structural Frame: Inspect the visible parts of the timber frame for signs of rot, insect infestation, or damage. Pay particular attention to areas around windows, doors, and the roof.
2. Floors and Ceilings: Check for any unevenness, sagging, or cracks in the floors and ceilings. These could indicate underlying structural issues.
3. Insulation: Assess the condition of the insulation, particularly in the walls and roof. Look for any gaps, dampness, or signs of deterioration.
4. Asbestos: Identify any areas where asbestos cement sheets are present. Ensure that these areas are undisturbed and consider having them professionally assessed and, if necessary, removed.

Utilities and Services

1. Electrical System: Ensure that the electrical system is up to date and compliant with current safety standards. Look for any exposed wiring or outdated fuse boxes.
2. Plumbing: Check for any leaks, corrosion, or blockages in the plumbing system. Ensure that the water pressure is adequate and that all fixtures are functional.
3. Heating and Insulation: Assess the condition of the heating system and the overall energy efficiency of the property. Consider the potential costs of upgrading insulation and heating.

Typical Defects and Maintenance Tips

Understanding the common defects in Formula houses can help you plan for necessary repairs and maintenance. Here are some typical issues and tips for addressing them:

Roof Maintenance

• Issue: The flat roof covered with bituminous felt is prone to water ingress and damage over time.
• Solution: Regularly inspect the roof for signs of wear and tear. Consider applying a new layer of bituminous felt or upgrading to a more durable roofing material.

Asbestos Management

• Issue: The presence of asbestos cement sheets in the external walls poses a health risk if disturbed.
• Solution: Have a professional asbestos survey conducted. If asbestos is found, consider encapsulation or removal by licensed professionals.

Structural Repairs

• Issue: Timber frame components can suffer from rot, insect infestation, or damage.
• Solution: Regularly inspect the timber frame for signs of deterioration. Treat any affected areas with appropriate preservatives and consider reinforcing or replacing damaged components.

Insulation Upgrades

• Issue: The original polystyrene insulation may not meet modern energy efficiency standards.
• Solution: Upgrade the insulation in the walls and roof to improve energy efficiency. Consider using modern materials such as spray foam or rigid foam boards.

Damp and Water Ingress

• Issue: Water ingress can lead to dampness, mould, and structural damage.
• Solution: Ensure that the property is adequately waterproofed. Address any leaks or damp areas promptly and consider installing a damp-proof course if necessary.

Conclusion

The Formula house represents a unique and innovative chapter in the UK’s construction history. While these properties offer distinctive architectural features and a glimpse into mid-20th-century building techniques, they also come with specific challenges and risks. As a prospective buyer or investor, it is crucial to conduct a thorough inspection and be aware of the typical defects and maintenance requirements associated with this property type.

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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By following the guidelines and tips provided in this article, you can make an informed decision and ensure that your investment in a Formula house is both safe and rewarding. Whether you are drawn to its unique design or its historical significance, the Formula house can be a valuable addition to your property portfolio with the right care and attention.