Overview
The Doric house is a concrete system-built house from the 1920s, manufactured by the Modern Building Co. It was built at a time of significant demand for affordable housing in the UK, when suburban development was expanding quickly, and the houses are found mainly in suburban areas.
The Modern Building Co. used prefabricated components and what were then modern construction techniques to speed up building. The design reflects the architecture of the 1920s, with an emphasis on function and simplicity. The houses are two-storey and semi-detached.
Typical characteristics & construction
The house sits on concrete strip footings with concrete underbuilding. The external walls are built around precast concrete block corner and intermediate piers, with 10-inch walls up to first floor level and 8-inch walls above. The walls are made up of roughcast building sheets, concrete and asbestos cement sheets, held with iron staples, with a timber wall plate, anchor irons and a moulded cement string course at first floor level.
The ground and first floors are timber boarding on timber joists. Ceilings are asbestos cement, a common material at the time. The roof is timber rafters covered with tiles or slates.
| Element | Typical construction | Inspection focus |
|---|---|---|
| Substructure | Concrete strip footings, concrete underbuilding | Subsidence, settlement, damp at the base of walls |
| External walls | PC block corner and intermediate piers; 10-inch walls to first floor, 8-inch above; roughcast building sheets, concrete, asbestos cement sheets | Cracks, bulging, movement, render condition, damp around piers and string courses |
| Reinforced concrete and fixings | PC block piers, iron staples, anchor irons, moulded cement string course, cement cover strips | Corrosion, spalling, cracking |
| Floors | Timber boarding on timber joists, ground and first floor | Unevenness, sagging, damage, timber decay |
| Ceilings | Asbestos cement | Cracks, staining, water damage, asbestos condition |
| Roof | Timber rafters, tiles or slates | Missing or broken tiles or slates, sagging, water ingress, rot in rafters |
Potential hazards & inspection priorities
Primary concern: reinforced concrete deterioration
The durability of the reinforced concrete components is the main structural concern with a Doric house. Over time the concrete deteriorates through carbonation and corrosion of the steel reinforcement, which leads to spalling, cracking and a loss of structural integrity, and the repairs that follow are costly. Exposed components such as the precast block piers and anchor irons should be checked for corrosion, spalling and other deterioration. Non-destructive testing, such as cover meters or ultrasonic testing, is a way of assessing the condition of the reinforcement.
Primary concern: asbestos
Asbestos cement sheets are used in the external walls and the ceilings. When disturbed, asbestos fibres become airborne and, if inhaled, cause serious respiratory disease, including asbestosis and mesothelioma. These materials should be handled with care and not disturbed, with professional help sought for removal or encapsulation. Regular inspection confirms that they remain in good condition and pose no risk to occupants.
Secondary concerns: structural movement and damp
Structural movement, such as subsidence or settlement, is a common issue in Doric houses. It shows as cracked walls, uneven floors and misaligned doors and windows. The cause needs to be identified before remedial work, which may include underpinning, crack stitching or concrete repair, with a structural engineer advising on the right approach.
Damp and moisture ingress are common in older properties of this kind. Poor ventilation, inadequate damp-proofing and deteriorating materials all contribute, leading to mould growth, timber decay and structural damage. Walls, floors and ceilings should be checked with a moisture meter, especially around windows and doors and at the base of external walls, and the source of any damp identified. Remedies include better ventilation, damp-proof courses and repair of damaged materials.
Long-term consideration: regular inspection
Regular inspection of the roof, external walls, floors, ceilings and structural components stops minor issues from developing into major problems. Before any inspection, the construction details, previous maintenance records and known issues should be gathered so the inspection can focus on likely problem areas.
Is this house right for you?
The Doric house has distinctive features and historical significance, but it carries real risks from its concrete, its asbestos and damp. In practice, its longevity and safety depend on thorough inspection followed by the right maintenance and repair.
- Commission a full building survey
- Establish the condition of the reinforced concrete components and any exposed steel
- Have asbestos-containing materials in the walls and ceilings identified and assessed
- Look for signs of structural movement and damp
- Gather any previous maintenance records
Being aware of these hazards before buying makes for a better-informed decision.
Mortgage & resale considerations
The Doric house is not designated defective under the Housing Defects Act 1984, but the potential for structural issues and the presence of asbestos make thorough inspection and maintenance necessary to meet safety standards.
What a survey can — and cannot — tell you
A building survey provides an informed assessment of the visible condition and construction of a Doric house. Inspections are non-intrusive and limited to areas that are accessible at the time of inspection.
- Identify visible cracking, spalling and corrosion to exposed concrete components and fixings
- Identify signs of structural movement in walls, floors, doors and windows
- Assess signs of dampness and moisture ingress, including with a moisture meter
- Comment on suspected asbestos cement in the walls and ceilings, and on the roof
- Highlight defects that may require repair, monitoring, or further investigation
However, there are limitations to what a survey can determine without intrusive investigation.
- Confirm the condition of steel reinforcement concealed within the concrete
- Measure carbonation or reinforcement condition without specialist testing
- Confirm whether materials contain asbestos without specialist sampling
- 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.
