Overview
The Douglas Special house was designed by A H Mottram and built in 1944, during the severe housing shortage caused by the Second World War. Only 64 were built. The houses are semi-detached bungalows and chalet bungalows, usually found in semi-rural or suburban areas, and they are of timber construction.
The need for rapid, cost-effective housing produced a range of system-built homes, the Douglas Special among them. The houses were designed to be assembled quickly from prefabricated components, a new approach at the time. Building them is described as a collaboration between local builders and timber suppliers working under Mottram's guidance, with the aim of a functional, well-proportioned home that could go up quickly.
Typical characteristics & construction
The substructure is brick on a concrete strip footing. The external walls are 2-inch solid timber planking, lined internally with fibreboard and sheathed externally with building paper. On the bungalows the planking is covered with diagonal timber boarding and then vertical timber boarding; the chalet bungalows have horizontal timber boarding throughout.
Internal partitions are timber studs. The first floor of the chalet bungalows is built on timber joists. The roof is timber rafters and purlins covered with concrete tiles.
Some elements are not documented. The separating wall between the pair is not well recorded, though it is likely to be timber stud like the partitions. The construction of the ground floor is not explicitly known, though it probably follows the timber joist construction typical of the period, and the ceilings are likely to be consistent with the timber construction of the rest of the house.
| Element | Typical construction | Inspection focus |
|---|---|---|
| Substructure | Brick on concrete strip footing | Moisture at ground level, settlement |
| External walls | 2-inch solid timber planking, fibreboard lining, building paper; diagonal and vertical boarding (bungalows) or horizontal boarding (chalet bungalows) | Rot, warping, damage, moisture near the ground and around windows and doors |
| Separating wall | Not well documented; likely timber stud | Condition, stability |
| Partitions | Timber stud | Stability, damage |
| Floors | Ground floor not explicitly known; timber joists at first floor | Decay, soft or spongy areas underfoot |
| Ceilings | Not documented | Sagging, cracks, water damage, secure fixing |
| Roof | Timber rafters and purlins, concrete tiles | Damaged or worn tiles, decay in rafters and purlins |
| Porch | Timber | Stability, decay, attachment to the main structure |
Potential hazards & inspection priorities
Primary concern: timber decay and insect attack
Prolonged exposure to moisture leads to rot and weakens the structure. The timber boarding should be examined for rot, warping and damage, with particular attention to areas where moisture collects, such as near the ground and around windows and doors. Soft or discoloured wood is the sign of rot, and the moisture causing it needs dealing with. Inside, the frame should be checked for decay, insect infestation and weakening, with a moisture meter used to find areas of high moisture content.
Timber-framed houses are susceptible to insect infestation such as woodworm. Small holes in the wood or sawdust-like frass indicate activity, and infestations need treating and preventing. Floors that feel soft or spongy underfoot point to problems in the joists below.
Secondary concerns: structural integrity and moisture protection
Over time decay, settling and general wear compromise the timber frame. Regular structural assessment is needed to confirm the house is safe and stable. Moisture ingress also brings mould growth, so proper drainage, weatherproofing and ventilation matter. The roof tiles should be checked for damage or wear, the rafters and purlins for decay, ceilings for sagging, cracks or water damage, and the timber porch for stability, decay and secure attachment to the house.
Secondary concern: asbestos
Given the period of construction, asbestos-containing materials may have been used in the original build. Asbestos poses significant health risks when disturbed, so a thorough survey to identify it is essential, with any asbestos safely managed or removed by a qualified professional.
Long-term consideration: insulation
The original construction did not prioritise insulation to modern standards, so energy efficiency is poor and heating costs higher. Insulation levels in the walls, floors and roof should be assessed, and retrofitting insulation improves efficiency and comfort.
Is this house right for you?
The Douglas Special is a historically significant house with real character, from a period when system building was new. It is a timber house of the 1940s, and the purchase should rest on firm evidence about the condition of that timber.
- Commission a full building survey
- Establish the condition of the timber planking, boarding and frame, including moisture content
- Have any suspected asbestos identified and assessed
- Allow for insulation improvements and ongoing timber maintenance
Thorough inspection and assessment are what confirm whether a particular house meets modern safety standards.
Mortgage & resale considerations
The Douglas Special house is not designated defective under the Housing Defects Act 1984. Given its age and construction method, thorough inspection and assessment are still essential to identify defects or hazards, and to establish whether the property meets modern safety and 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 Douglas Special house. Inspections are non-intrusive and limited to areas that are accessible at the time of inspection.
- Identify visible rot, warping and damage to the timber boarding and porch
- Assess signs of dampness and moisture ingress, including moisture meter readings
- Identify signs of insect activity such as flight holes and frass
- Comment on the roof coverings, accessible roof timbers, ceilings and floors
- 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 the solid planking concealed behind boarding and linings
- Establish the undocumented construction of the separating wall and ground floor
- 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.
