Overview
The Lowestoft Borough house is a concrete house built in the 1920s. It was designed by S W Mobbs and produced by Lowestoft Borough Council, the local authority responsible for a range of public housing projects at the time. The 1920s saw significant housing development in the UK, driven by the need for affordable homes for working people, and these houses were part of the effort to address the housing shortage after the First World War.
The houses are found mainly in Lowestoft, the coastal town in Suffolk, where they sit in residential areas, often as part of larger estates developed by the council.
Typical characteristics & construction
The house stands on concrete strip footings. Above them, the underbuilding is formed from double L-section precast concrete blocks that create a channel filled with concrete, giving the base of the walls additional stability and strength.
The external walls follow the same principle. L-section dense aggregate precast blocks and L-section clinker aggregate precast blocks together form a channel that is filled with concrete, producing a robust wall that resists weathering. The ground floor is concrete, a solid base that withstands significant loads and needs relatively little maintenance.
Details of the roof construction are not known. It is likely to follow the practice of the 1920s, such as timber framing with slate or tile coverings, but this cannot be assumed for any particular house.
| Element | Typical construction | Inspection focus |
|---|---|---|
| Substructure | Concrete strip footings; double L-section precast block underbuilding forming a channel filled with concrete | Signs of subsidence or movement |
| External walls | L-section dense aggregate and clinker aggregate precast blocks forming a channel filled with concrete | Cracking, spalling, joints between blocks, moisture ingress |
| Reinforced concrete | Concrete used throughout the structure | Rust staining, cracking, carbonation depth |
| Ground floor | Concrete | Cracking, unevenness, deterioration, level and stability |
| Roof | Not known | Missing or damaged coverings, water ingress, structure, ventilation and insulation |
Potential hazards & inspection priorities
Primary concern: durability of the reinforced concrete
The durability of the reinforced concrete is the main concern with this type. Over time the reinforcement is susceptible to corrosion, particularly where the concrete is exposed to moisture, and corrosion leads to structural problems that can compromise the safety of the house. Rust staining and cracking are the signs to look for.
Carbonation adds to the risk. Carbon dioxide from the air reacts with the calcium hydroxide in the concrete to form calcium carbonate, which lowers the alkalinity of the concrete and leaves the steel more vulnerable to corrosion. Measuring the carbonation depth establishes how far this has progressed. Detailed guidance on assessing reinforced concrete durability is given in BRE Digest 444 and BR 19. Where carbonation is found, protective coatings or repairs are the usual responses.
Secondary concerns: cracking, spalling and moisture
Cracking and spalling are common in reinforced concrete structures, caused by moisture ingress, freeze-thaw cycles and corrosion of the reinforcing steel. In practice the joints between the precast blocks and the areas of poured concrete are where the walls need the closest attention. Moisture getting in causes corrosion of the steel, deterioration of the concrete and mould growth, so the walls, roof and windows all need to keep water out. Regular inspection and timely repair extend the life of the house.
Long-term consideration: the roof
Because the roof construction is not recorded, it has to be judged on inspection. Missing or damaged coverings, water ingress and the integrity of the roof structure all need checking, and the roof should be properly ventilated and insulated to prevent condensation and heat loss.
Is this house right for you?
The Lowestoft Borough house has historical significance and gives a clear insight into council housing of the 1920s. Its condition rests on the concrete, so a purchase should follow a careful assessment of the walls rather than their appearance.
- Commission a full building survey
- Establish the condition of the concrete walls, including any rust staining, cracking or spalling
- Have carbonation depth assessed where the concrete shows signs of deterioration
- Check the roof, its ventilation and its insulation
A thorough inspection and assessment identifies the issues that need attention and whether the house meets current building standards.
Mortgage & resale considerations
The Lowestoft Borough house is not classed as defective under the Housing Defects Act 1984. A thorough inspection and assessment is still essential to identify any issues and to establish whether the house meets current building standards.
What a survey can — and cannot — tell you
A building survey provides an informed assessment of the visible condition and construction of a Lowestoft Borough house. Inspections are non-intrusive and limited to areas that are accessible at the time of inspection.
- Identify visible cracking, spalling and rust staining to the concrete walls
- Assess signs of dampness, moisture ingress, and condensation risk
- Comment on roof coverings, ventilation, insulation and the external envelope
- Review the condition of the concrete ground floor
- Highlight defects that may require repair, monitoring, or further investigation
However, there are limitations to what a survey can determine without intrusive investigation.
- Measure carbonation depth in the concrete
- Confirm the condition of reinforcement concealed within the concrete
- Confirm a roof construction that is concealed or not recorded
- 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.
