Overview
The Waller house is a precast reinforced concrete house from the 1920s. It was designed by J H de W Waller and manufactured by Waller Housing Corporation Ltd and Hill Richards & Co. The design was a response to the housing shortage after the First World War, when rapid and cost-effective building methods were needed.
The houses were built during the housing boom of the 1920s and are typically found in suburban areas, reflecting the expansion of housing beyond city centres at the time. They are two-storey and semi-detached, and their construction methods and materials make them a distinctive part of the UK's housing stock.
Typical characteristics & construction
The substructure of the Waller house is not documented. The external walls are built around dense reinforced concrete columns, with a timber subframe acting as permanent formwork to the columns and ring beams, and dense RC ring beams at first floor and eaves level. Between the columns are storey-height dense PRC panels, a cavity and an inner leaf of clinker PRC panels, which add insulation.
The separating wall is formed of precast concrete panels, and the partitions are block or brick. The ground floor is concrete, and the first floor is PRC slabs on PRC floor beams.
The roof is made up of tray-shaped PRC roof slabs with timber rafters and battens, covered with slates. On some houses timber and slate covers have been added to the roof, secured with 1-inch diameter tie bars.
| Element | Typical construction | Inspection focus |
|---|---|---|
| Substructure | Not documented | Signs of movement in the walls and floors above |
| External walls | Dense RC columns and ring beams, timber subframe as permanent formwork, dense PRC panels, cavity, clinker PRC panels | Cracking, spalling or damage to columns and panels; rot or deterioration of the timber subframe |
| Cover strips | Exposed vertical PRC cover strips and beams | Cracking and spalling |
| Separating wall and partitions | PC panels; block or brick partitions | Cracking, movement, integrity of the separating wall |
| Floors | Concrete ground floor; PRC slabs on PRC floor beams at first floor | Cracking or unevenness; damage to slabs and beams |
| Roof | Tray-shaped PRC roof slabs, timber rafters and battens, slates; some with added timber and slate covers on tie bars | Leaks through PRC roof units, damage, wear, security of slates |
Potential hazards & inspection priorities
Primary concern: cracking and spalling of the PRC cover strips
Cracking and spalling of the PRC cover strips is one of the most common issues with Waller houses. Left unaddressed, it leads to structural weakness and safety hazards. The dense RC columns and PRC panels should be checked for cracking, spalling and other damage at the same time, and the timber subframe and ring beams for rot or deterioration.
Secondary concern: leaks through the PRC roof units
Leaks through the PRC roof units are another common problem. They cause water damage inside the house and, left untreated, lead to more serious structural issues. The roof slabs, rafters and battens should be checked for leaks, damage and wear, and the slate covering for security.
Long-term consideration: added roof covers
Where timber and slate covers have been added to the roof on 1-inch diameter tie bars, they improve appearance and weather resistance but bring their own maintenance requirements.
Is this house right for you?
The Waller house is a historically significant type, with robust construction and a distinctive design. It also carries specific risks and maintenance requirements, and its designated defective status has to be weighed before any purchase.
- Commission a full building survey
- Check the PRC cover strips, columns and panels for cracking and spalling
- Look for evidence of leaks through the PRC roof units
- Establish whether timber and slate roof covers have been added, and their condition
Understanding these points is what allows a buyer to make an informed decision about a Waller house.
Mortgage & resale considerations
Waller houses are designated as defective under the Housing Defects Act 1984. The designation means these houses may have inherent structural issues that pose risks to occupants. Buyers need to be aware of the classification and take it into account when weighing up the costs and benefits of buying.
What a survey can — and cannot — tell you
A building survey provides an informed assessment of the visible condition and construction of a Waller house. Inspections are non-intrusive and limited to areas that are accessible at the time of inspection.
- Identify visible cracking and spalling to PRC cover strips, columns and panels
- Assess signs of leaks through the PRC roof units and water damage inside
- Comment on the slate covering and any added timber and slate roof covers
- Review the general condition of accessible floors, partitions and the separating wall
- 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 reinforcement concealed within the PRC and RC components
- Assess the timber subframe hidden within the walls
- Establish the form or condition of the substructure
- 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.
