How to build a nestbox in a wall cavity

Building conservation is fraught with ethical dilemmas. At one extreme there is pressure to freeze buildings at a particular point in time and another to modernise them beyond all recognition. One thing that gets overlooked is that buildings are something that all of us borrow for a few years before we “move on”. Modern life tends to make us too busy to notice our journey through our buildings and how it is interwoven with many other species. As part of on-going research into historic buildings as “ecosystems”, the author presents an opportunity to use a small recess in an old masonry wall to accommodate a nest box

Silverfish: if they're not fish, they're not really silver, and they look like aliens, what on earth are they?

As part of a series of studies exploring the complex relationship between buildings and ecology, this piece considers the place of silverfish within part of a wider ecosystem. The artlcle presents some of the issues involved with having silverfish and what methods can be used to reduce numbers to avoid infestation

Development and validation of risk prediction equations to estimate future risk of heart failure in patients with diabetes: a prospective cohort study

Objective: To develop and externally validate risk prediction equations to estimate the 10-year risk of heart failure in patients with diabetes, aged 25–84 years. Design: Cohort study using routinely collected data from general practices in England between 1998 and 2014 contributing to the QResearch and Clinical Research Practice Datalink (CPRD) databases. Setting: We used 763 QResearch practices to develop the equations. We validated it in 254 different QResearch practices and 357 CPRD practices. Participants: 437 806 patients in the derivation cohort; 137 028 in the QResearch validation cohort, and 197 905 in the CPRD validation cohort. Measurement: Incident diagnosis of heart failure recorded on the patients’ linked electronic General Practitioner (GP), mortality, or hospital record. Risk factors included age, body mass index (BMI), systolic blood pressure, cholesterol/ high-density lipoprotein (HDL) ratio, glycosylated haemoglobin (HbA1c), material deprivation, ethnicity, smoking, diabetes duration, type of diabetes, atrial fibrillation, cardiovascular disease, chronic renal disease, and family history of premature coronary heart disease. Methods: We used Cox proportional hazards models to derive separate risk equations in men and women for evaluation at 10 years. Measures of calibration, discrimination, and sensitivity were determined in 2 external validation cohorts. Results: We identified 25 480 cases of heart failure in the derivation cohort, 8189 in the QResearch validation cohort, and 11 311 in the CPRD cohort. The equations included: age, BMI, systolic blood pressure, cholesterol/HDL ratio, HbA1c, material deprivation, ethnicity, smoking, duration and type of diabetes, atrial fibrillation, cardiovascular disease, and chronic renal disease. The equations had good performance in CPRD for women (R2 of 41.2%; D statistic 1.71; and receiver operating characteristic curve (ROC) statistic 0.78) and men (38.7%, 1.63; and 0.77 respectively). Conclusions: We have developed and externally validated risk prediction equations to quantify absolute risk of heart failure in men and women with diabetes. These can be used to identify patients at high risk of heart failure for prevention or assessment of the disease

Oak trees, timber conversion and the structure of traditional timber-frame buildings

In the climate of Northern Europe keeping warm and dry during the long winters is a key priority reflected in the form and materials of our traditional buildings. Builders have always been pragmatic when sourcing materials especially within the vernacular traditions and although large parts of the British Isles have used stone and cob, timber-frame buildings have always been the best response to the weather. A steep roof pitch and a dry building platform enabled the creation space with potentially very satisfactory comfort levels especially if a fire can be safely deployed. Of all the trees available, it is the oak that has lent itself to providing the most suitable material to create such frames. Like all timber, oak has the ability to function within a frame structure in both compression and tension. Pegs, ties and braces combine to create stable structures capable of transferring all loads effectively and efficiently to the ground

Oak trees, carpentry traditions and timber conversion

There is a potential inter-relationship between the two main species of oak and the carpentry traditions of timber-frame buildings within the British Isles. It is suggested that natural distributions pre-date the development of carpentry traditions and that subsequent woodland management and the ability to convert timber using water power might have perpetuated the distribution until relatively recent times. In addition a suggestion is made that there may also be a link between cruck frames and the technology to produce appropriate sash-mounted saws and the ability to harness waterpower

Carpentry Traditions and Timber-Frame Buildings

Despite much of the forests being cleared in advance of agricultural expansion, areas of oak woodland have been managed as a valuable resource passed on from one generation to the next. The longevity of oak trees has required long term planning and an ability to forecast the demand of great grandchildren and beyond. Depending on circumstances, this management would have happened historically within family groups, or perhaps on a communal basis as part of the feudal system. Prior to the 1840s and the introduction of rotating “circular” saws, saw mills exclusively used a vertical movement for converting the trees into timber. Saw mills were traditionally powered by water, with the rotary motion of the wheel being transferred via a crank shaft to a rip-saw blade mounted in a vertical wooden frame known as a sash. The introduction of steam power would have also contributed to the demise of water power for timber conversion in the UK

Hole In The Wall

Often in the repair process we overlook the fact that buildings are borrowed vessels, used for a few years before we “move on,” and that our journeys through them overlaps with many other species. Not long ago, as part of my on-going research into historic buildings as ecosystems, I stumbled across a stone wall of a house that had enough of an eroded recess to accommodate a nest box

Hearts Of Oak: Traditional Timber Frames and Timber Conversion.

Traditionally, timber would have been cut down and prepared using axes, with wedges used for splitting and adzes for finishing surfaces. The ability to produce wrought iron enabled the production of metal that could be shaped, toothed and sharpened to form saw blades. Prior to the 1840s and the introduction of rotating “circular” saws, saw mills exclusively used a vertical movement for converting the trees into timber. Saw mills were traditionally powered by water, with the rotary motion of the wheel being transferred via a crank shaft to a rip-saw blade mounted in a vertical wooden frame known as a sash