Historical Context and Background

The Connell House, also known as the Phoenix, is a unique and rare property type in the UK. Manufactured by J N Connell Ltd and designed by Sam Buxton & Associates, these houses were built in 1946, immediately post-World War II. Only two of these properties were ever constructed, making them a rare find in the property market. These two-storey semi-detached houses are typically located in areas that saw significant post-war reconstruction efforts.

Identification Characteristics

Connell Houses are easily identifiable by their distinctive architectural features. They have a shallow pitch gable roof covered with profiled asbestos cement sheets. The external walls are made of rendered storey-height precast concrete (PC) panels. The houses also feature a PC fascia and soffit, as well as a PC canopy over the front door. One of the most distinctive features is the front elevation ground floor windows, which consist of a wide and narrow window separated by a mullion.

Key Identification Features:

• Two-storey semi-detached structure
• Shallow pitch gable roof with asbestos cement sheets
• Rendered storey-height PC panels for external walls
• PC fascia, soffit, and canopy over the front door
• Distinctive front elevation windows with a mullion

Construction Details

Substructure

The substructure of Connell Houses consists of concrete strip foundations and brick under-building. A PC plinth and damp-proof course (DPC) are also present to prevent moisture ingress.

Frame

The frame is composed of 14 tubular steel stanchions, with three being single-storey. There are four PC perimeter beams and PC floor support beams. The frame layout includes two double PC beams forming an I-beam for floor support, three rolled steel angle (RSA) roof trusses, and seven RSA purlins. The protective coating for the frame includes red lead paint and agraphite.

External Walls

The external walls are made of rendered storey-height PC panels, insulated with mineral wool. Timber battens and plasterboard line the interior.

Separating Wall

The separating wall between the semi-detached units is a clinker concrete slab cavity wall, providing both structural integrity and sound insulation.

Partitions

Internal partitions are constructed from timber studs lined with plasterboard.

Floors

The ground floor consists of tongue-and-groove (T&G) boarding on timber joists, while the first floor features T&G boarding on timber battens.

Ceilings

Ceilings are made of plasterboard, providing a smooth finish and additional fire resistance.

Roof

The roof is covered with profiled asbestos cement sheets, a common material used in post-war construction due to its durability and fire-resistant properties.

Typical Hazards and Risks

Asbestos

One of the most significant hazards associated with Connell Houses is the presence of asbestos in the roofing material. Asbestos cement sheets were commonly used in the mid-20th century due to their fire-resistant properties. However, asbestos poses severe health risks if disturbed, leading to respiratory issues and diseases such as mesothelioma.

Structural Integrity

The tubular steel stanchions and PC beams are susceptible to corrosion, especially if the protective coating has deteriorated over time. Corrosion can compromise the structural integrity of the house, making regular inspections crucial.

Damp and Moisture

The concrete strip foundations and brick under-building can be prone to damp and moisture ingress, especially if the DPC is compromised. This can lead to mould growth and structural damage over time.

Insulation

The mineral wool insulation used in the external walls may have degraded over time, reducing its effectiveness. Poor insulation can lead to higher energy costs and reduced thermal comfort.

Defective Premises Act

Connell Houses are not specifically classed as defective under the Defective Premises Act. However, given their age and the materials used in their construction, they may require significant maintenance and upgrades to meet modern building standards.

Inspection Guidelines for Surveyors

Preliminary Checks

Before conducting a detailed inspection, surveyors should review historical records and previous inspection reports. This will provide valuable context and help identify areas that may require closer examination.

External Inspection

Roof

• Check for signs of damage or wear on the asbestos cement sheets.
• Inspect the roof trusses and purlins for signs of corrosion.
• Ensure that the roof is adequately ventilated to prevent condensation.

Walls

• Examine the rendered PC panels for cracks or signs of deterioration.
• Check the condition of the PC fascia, soffit, and canopy.
• Inspect the separating wall for any signs of structural issues.

Internal Inspection

Floors

• Check the ground and first floors for signs of sagging or unevenness.
• Inspect the timber joists and battens for signs of rot or insect infestation.

Partitions

• Examine the timber stud partitions for signs of damage or wear.
• Check the plasterboard for cracks or signs of moisture ingress.

Ceilings

• Inspect the plasterboard ceilings for signs of sagging or water damage.
• Check for any signs of mould or mildew.

Utilities

• Ensure that the electrical and plumbing systems meet current safety standards.
• Check for any signs of leaks or corrosion in the plumbing system.

Typical Defects and Maintenance Tips

Roof

The asbestos cement sheets on the roof can become brittle and prone to cracking over time. Regular inspections are essential to identify any damage early. If asbestos is disturbed, it should be handled by professionals trained in asbestos removal.

Walls

The rendered PC panels can develop cracks, especially if the house has settled unevenly. These cracks should be repaired promptly to prevent moisture ingress and further deterioration.

Floors

The timber joists and battens can be susceptible to rot and insect infestation. Regular inspections and prompt repairs are essential to maintain the structural integrity of the floors.

Insulation

The mineral wool insulation may need to be replaced or supplemented to improve thermal efficiency. Upgrading the insulation can significantly reduce energy costs and improve comfort.

Variants and Modifications

Concrete Ground Floor

Some Connell Houses may feature a concrete ground floor instead of timber joists. This variant can provide better resistance to moisture and pests but may be more challenging to repair if damaged.

PC Suspended Ground Floor

A PC suspended ground floor can offer improved structural integrity and resistance to moisture. However, it may require specialized knowledge and materials for repairs.

Lightweight PC Slab Inner Leaf

Some variants may feature a lightweight PC slab inner leaf in the external walls. This can provide additional insulation and structural support but may require specialized maintenance.

Masonry Partitions

Masonry partitions can offer improved sound insulation and fire resistance compared to timber stud partitions. However, they may be more challenging to modify or repair.

Conclusion

Connell Houses, with their unique construction and historical significance, offer a fascinating glimpse into post-war British architecture. While they come with their own set of challenges, including asbestos and potential structural issues, they can be a worthwhile investment with proper maintenance and care. Regular inspections and prompt repairs are essential to ensure the longevity and safety of these rare properties.

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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