Belgian firm Urbain Architectencollectief has refurbished a former brick fire station building and added an extra storey to house additional facilities for a cultural centre in the city of Kortrijk (+ slideshow). More about Urbain Architectencollectief converts brick fire station into Kortrijk cultural centre
News: Danish studio COBE has unveiled its designs for an extension to the Red Cross headquarters in Copenhagen, comprising a large triangular structure that rises up from the ground at an angle to meet the existing building. More about COBE reveals competition-winning Volunteer House design for Danish Red Cross
The upper storey of this brick extension to a mid-century home in north London by Lipton Plant Architects projects over the entrance to form a porch (+ slideshow). More about Lipton Plant Architects adds pale-brick extension to north London home
Pale wooden window frames contrast with the black-stained cedar facades of this extension to a detached house in Nantes by French studio Bertin Bichet Architectes (+ slideshow). More about Nantes house extension contrasts blackened wood facades with pale window frames
A glass-fronted stairwell joins a craggy stone Portuguese house to its new concrete extension by Filipe Pina + Maria Inês Costa (+ slideshow). More about Filipe Pina + Maria Inês Costa add concrete extension to stone house in Portugal
The steeply angled roofs of a wooden pavilion and extension by Bent Architects will screen a family home in Australia from a "monster" development on an adjoining plot of land (+ slideshow). More about Bent Architecture's wooden extension screens a Melbourne home from neighbouring "McMansion"
The street-facing elevation of this brick and steel extension to a 1920s Montreal property echoes the proportions of the original building, but at the rear a large angular outcrop projects over the back garden (+ slideshow). More about Steel cladding frames an offset window at Montreal house extension by Naturehumaine
A marble-lined steam room is squeezed below the sloping ceiling of this apartment extension in Lisbon by local studio Camarim Arquitectos (+ slideshow). More about Lisbon apartment extended by Camarim Arquitectos to include an attic steam room
Spanish studio MX_SI added vertical wooden mullions to the exterior of this museum extension in Mänttä, Finland, to evoke the trunks of trees in the surrounding park (+ slideshow). More about MX_SI's addition to the Serlachius Museum Gösta has a stripy facade based on an "abstract forest"
Italian studio Massimo Galeotti Architetto has filled in the empty corner of a house in Treviso with a timber-clad extension to provide space for a new music room (+ slideshow). More about Massimo Galeotti adds modern timber infill to the corner of an old Italian villa
A freestanding concrete staircase spirals between the floors of this timber-frame and stone building remodelled by the founders of A1 Architects to form their own home and studio in Prague (+ slideshow). More about Charred-timber extension by A1 Architects transforms an old cottage into a home and studio
Crinkled fibre-cement panels clad the facade of this theatre extension by Finnish studio ALA Architects in the city of Kuopio, complementing the concrete exterior of the original 1960s building (+ slideshow). More about ALA's Kuopio City Theatre extension features a crinkled facade
Atelier Data has extended a 1980s home in the Algarve, Portugal, with whitewashed concrete structures and fenced-in courtyards (+ slideshow). More about Atelier Data adds concrete volumes and internal courtyards to Algarve house
Two oversized sash-style windows have been added to the back of this two-storey extension by Sydney architects Panovscott, allowing both levels to open up completely to the garden (+ slideshow). More about Giant sash windows cover the back of Panovscott's Sydney house extension
A strip of glazing cuts through the middle of this two-storey extension to a Georgian property in west London, by Norton Ellis architects (+ slideshow). More about Norton Ellis extends Georgian basement flat with glass and brick "outhouses"
This gabled extension to a brick house in the Netherlands was designed by Studio Prototype to mimic the shape of the original property but is clad in an entirely different material. More about House W extension by Studio Prototype contrasts stripy cedar with original brickwork
A zigzagging roof extends across this extension added to the original gable end of a community centre in the Swiss municipality of Oberglatt by Zurich studio Frei + Saarinen (+ slideshow). More about Frei + Saarinen adds a zigzagging roof to a community centre extension in Switzerland
This extension by French architect Clément Bacle mirrors the size and shape of the original brick house it adjoins, but uses modern materials to distinguish it as new (+ slideshow). More about House Between the Two extension by Clément Bacle mirrors original house
Eastabrook Architects and Jonathan Tuckey Design have added a contemporary glazed extension to a Grade II-listed Cotswolds house to provide additional space without detracting from the original building (+ slideshow). More about Eastabrook Architects and Jonathan Tuckey Design add glazed extension to Grade II-listed Yew Tree House
Gianni Botsford Architects has added a subtle extension to a London townhouse, which is partly submerged in the garden and has transparent walls to help camouflage it from sight (+ slideshow). More about Gianni Botsford sinks "invisible" extension into the garden of a London house