How we construct our buildings now is the result of a long historical process of trial and error which goes back thousands of years. Prior to the 20th Century the principal building materials were brick, stone and timber and the suitability and strengths of these materials were well understood by the craftsmen using them as was the durability of the tiles, slates and metals used to cover our roofs. Houses built in a traditional manner using these materials are universally accepted by mainstream mortgage lenders as suitable security provided that they are in good condition and in a saleable location.
The 20th Century was a time of experiment however when new forms of construction were being promoted including metal frames, pre-cast concrete panels and plastics. A government agency which was able to test and evaluate new forms of construction seemed like a good idea.
The Building Research Establishment (BRE) started life as a government run organisation (the Building Research Board) in 1921 as part of an effort to improve the quality of housing in the UK following the First World War. Following that war, politicians promised to build homes fit for heroes including, for the first time, large scale municipal housing estates.
The Building Research Board expanded and incorporated many other organisations to become the modern BRE and in 1997 it was privatised with the ultimate ownership transferred to a charity, the BRE Trust, that works to support research and education in the built environment. The BRE is therefore not now run, or owned, by the Government
When surveyors are faced with novel or unusual construction the BRE is often the first port of call for advice since it tests and evaluates materials and construction methods and publishes its results and conclusions in technical papers. If there is disagreement as to whether a particular form of construction is suitable security it is likely that the surveyor will consult the relevant BRE publications.
The main BRE headquarters and research facility is based at Garston, just to the north of Watford. Conducted tours are available for visitors to see current BRE projects which include, as one might expect, lots of work on Modern Methods of Construction (MMC) and home insulation. As an interesting diversion in the grounds there is a 1:50 scale model of the German Mohne reservoir and dam used by the inventor Barnes Wallis to test the famous bouncing bomb used by the Dam Busters in the Second World War.
All the main mortgage lenders issue Guidance Notes to their surveyors setting out in some detail their requirements for mortgage securities to be acceptable but the underlying principles are fairly universal. The mortgage security should be readily saleable in the event of repossession and should have a life expectancy of at least 30 years beyond the end of the mortgage term. In effect a building should last at least 60 years without needing any significant reconstruction.
Traditionally built houses and flats will last much longer than 60 years of course. A well-constructed house may well last hundreds of years if it is properly maintained.
The first major problem to arise with what we surveyors call “non-standard construction” came in the 1980s. It became apparent that many houses and flats – mostly on local authority estates – which had been purchased and were owner-occupied had become unsaleable. In order to satisfy mortgage lender’s criteria these houses, built using pre-cast concrete panels or steel frames, needed to be repaired and upgraded.
BRE undertook a comprehensive investigation identifying more than 300 different forms of non-standard construction which had been used in the 1930s and especially in the post war period from 1945 to 1960. BRE provided advice on suitable repair strategies and this culminated in the Housing Defects Act 1984 which included provisions for structural repairs to be grant aided and signed off by suitably qualified structural engineers.
The houses repaired under the 1984 Act with suitable certificate in place were then acceptable mortgage security for mortgage lenders to lend on and this remains the case today.
Fast forward to the 21st Century and BRE is evaluating modular construction, MMC and cladding. How we upgrade the insulation to our homes to meet zero carbon targets will be an ongoing issue.
In addition to the issues surrounding modern construction surveyors also have to deal with mortgage lending on very old buildings which may be built of cob, wattle and daub and timber. We may have to consider mortgage applications on converted oust houses, windmills, water towers and the like. The surveyor in these circumstances often has to ask for a specialist report. The basic principles still apply: will it be readily saleable and what is the life expectancy.
Peter Glover is surveyor and author of Building Surveys and Buying a House or Flat
