Craigs Rock Garden Studio, named after the local area, was designed primarily as an office for my one-man architectural practice while also providing additional family space - a TV provides an additional kids area while the generous covered patio area provides a barbecue area suitable for a typical Northern Irish summer!
As my full time workplace, energy efficiency was a key design consideration in order to reduce running costs and provide a comfortable working environment. A simple square floor plan was adopted as it has less external surface areas than more complex shapes, reducing the amount of floor, wall and roof areas to lose heat through... and their associated construction costs!
The principles of the German Passivhaus standard were applied to the external fabric. The studio was constructed using a site built timber frame and roof incorporating high levels of continuous insulation with minimal thermal bridges to reduce heat loss through conduction. Internally, the walls and ceilings contain a service void with an aluminium foil face, which acts as an air tightness layer reducing heat loss through convection, while the reflective surface limits radiative heat transfer.
Externally, the wall and roof cladding voids contain a reflective breathable membrane to further improve thermal performance while also reducing the risk of summer overheating. A hand floated concrete floor provides thermal mass to the otherwise light-weight structure to further reduce the risk of overheating, by absorbing heat during daytime and releasing it when the temperature drops at night. This also saved money on additional floor finishes! Triple glazed windows, door and roof light ensures the thermal performance of the external fabric is maintained while also providing good cross ventilation and plenty of natural light.
The effort invested in the quality of the thermal envelope has been well worth it - the computer and printers etc provide the main heating load, which only needs topped-up on the coldest of days with a 500W electrical vegetable oil filled radiator. LED light fittings have been provided throughout as a further energy saving measure although the centrally located roof light means they are rarely needed.
Internally, low VOC paints have been used to improve indoor air quality in conjunction with an air filtering indoor house plant (Red-edged Dracaena) as recommended by NASA for filtering harmful toxins and pollutants from the air. My main work area is a bespoke fitted desk made from birch plywood and galvanised steel frame incorporating a secret pull-out desk - this can be pulled out for occasional use during meetings etc but easily stored away to free up valuable floor space. Birch ply shelves are supported above using galvanised wire rope hung from the main roof structure. An additional high level ceiling storage area (which explains the roof shape) accommodates a large plotter/printer to further maximise the useable floor space.
Externally, the base supporting the main timber frame is built using red brick, left over from an extension previously added to our house. This also helped create an aesthetic link between the two buildings. The walls are clad on the two most prominent sides facing the garden with Siberian Larch, which was left untreated to weather naturally to avoid any future maintenance requirements... cheaper and less hassle for me in the long term! Projecting galvanised steel angles where used as a trim around the external openings. Galvanised corrugated sheeting was used on the rear walls facing the boundary and on the roof.
A galvanised steel gutter cantilevers out over the patio area with a rain chain transferring the rainwater into a rock filled gabion box - the rock coming from the very ground of Craigs Rock during initial excavations. This done away with installing any underground drainage and also creates a nice water feature when enjoying the Norn Iron summer barbecues!!!