Windtightness breather membrane.
Perforated metal profile
Battens, 25x50mm
Douglass Fir Counterbattens, 75x50mm thick @ 900mm c/c.
Steico sheathing board, 22mm thick
Timber I-beam, 400mm width with pump-filled Warmcell insulation
Pump-filled Warmcel insulation
Ceiling counterbattens
Ceiling battens
Ceiling boards of timber with half-lap joint
Airtightness membrane
Airtightness seal
Clay plaster on interior wall face, 25mm thick
Load-carrying timber (ring) beam
(timber straw) panel, 400mm thick
Exploded Axonometric Detail
Old Holloway Cottage Little Birch, Herefordshire, UK
Scale 1:5, A2 Paper
Matte black corrugated roofing sheet
Roofing screw
Rainscreen fastening screw
Ecococon
STEICOprotect wood fibre board, 60mm thick
Timber rainscreen charred on site
Rainscreen fixing counter battens support
Building Old Holloway Cottage
Architect Juraj Mikurcik [also the owner]
Location Herefordshire, UK
99m2
Background: Old Holloway is a self-built timber building, clad in charred cedar wood and roofed with corrugated sheets. It perches on a gentle south-facing slope of rural Little Birch, Herefordshire, United Kingdom. Juraj Mikurcik, the owner and architect designed the house to reflect a modest farmhouse which previously occupied a portion of the site hence its rustic appearance. The design language was partly influenced by the Duchy of Cornwall who owned the site as a part of a larger land portfolio and wanted the newly erected structure to reminisce the agricultural setting.
Construction: The foundation is a 250mm thick Isoquick® Expanded Polystyrene insulation tub within which reinforced concrete is poured to form the floor slab. Next, the wall is built up from prefabricated modules supplied by Ecococon. The modules are timber and compressed straw cassettes each measuring about 600x800mm weighing not more than 120kg. The interior wall face was faced with wire mesh and then plastered with clay to achieve a solid feel. On the exterior face of the wall, it is clad with narrow cedar ‘rainscreen’ planks which were charred on site with a blowtorch to give it the black colour. The roof it is made of wooden I-beam joists pump-filled with Warmcel’s recycled newspaper insulation. Corrugated sheets given a black painted finish crowns the entire roof structure. Doors are made of exposed Douglas fir timber to celebrate its natural finish. The windows and main entry door are Passivhaus-certified Smartwin products.
Energy Performance: The residents reported that between the Summer and Autumn of 2017, the average indoor temperature ranged from 20 to 21°C. They only started using indoor heating in November of that year. In 2018, the outdoor temperature averaged between 25 - 27°C while the indoor temperature peaked at 22°C or 23°C and would regularly fall to 20°C at night. The building temperature regulation was so good that there was no overheating during the summer of 2018. The wood chip stove heats the house by radiation as there is no underfloor pipe heating system. Hot water for the bathroom and towel rails are catered for using an air-source heat pump with an integrated heat recovery system. The south-facing windows are protected from unwanted solar penetration by deep eaves and window reveals. Whenever necessary, cross ventilation at night is facilitated by openable windows fitted with fly mesh to prevent insect infiltration.
Costs: The procurement cost for the building was about £150,000 with no adjustment for inflation. Monthly electricity bill is about £55. That is to say in six months of winter, electricity cost averages at £330 - about 5 times less than the £1500 winter heating bill that the homeowners used to incure in their previous home. Due to this, Passivhaus certified the building as a £0 energy cost building.
Sustainable Materials: Low-impact and sustainable materials, some of which can be easily obtained include, PEFC certified Timber products, straw, Fermacell drywall lining, clay plaster, recycled newspaper cellulose, and sheep wool.
