Architect Simon Astridge employed a varied material palette of plywood, concrete, brick and stone to create this extension to a Victorian terraced house in London  (+ movie).

The client asked London-based Simon Astridge to completely refurbish the interior of the property in Balham, south London, and increase the total floor area without overtly disrupting the character of the Victorian street.

The architect added three extensions spread across different levels at the rear of the house and used a variety of materials to differentiate them from the original features.

Frameless skylights punctuating the ceiling on the top floor allow views of the sky from within various rooms.

"The concept involved choosing five materials as a palette for the project; these were concrete, plywood, brickwork, natural stone and the sky," said Astridge.

A new kitchen and dining room added to the rear of the house was constructed from cast concrete, with the party walls left exposed both externally and internally.

The dining space features a plywood roof supported by laminated plywood beams that perch on top of the walls, with the central layer set back to give the structure a lighter appearance and create a channel for wiring.

The end wall incorporates a window seat that projects out towards the garden and a large glazed door that swings out to connect the interior with a patio area.

A staircase lined with birch plywood ascends to the bedrooms on the first and second floors, and is illuminated by a frameless skylight that enables daylight to penetrate down through the house.

When it rains, the water drops can be seen creating ripples on the surface of the skylight, and pools that gather afterwards cast shadows on the adjacent walls when the sun comes out.

"Just after it has finished raining and the sun comes out – quite often in London – the sunlight pierces through temporary pooled parts of rainwater that shimmer and reflect onto the plywood wall finishes below. It wasn't planned for, but it is magical," said Astridge.

The top storey is dedicated to a master bedroom suite with the bedroom itself fitted underneath the eaves. These eaves are left exposed to give the impression that the usable floor space extends all the way to the edges of the building.

Walls, floors and ceilings in the master bedroom, en suite and dressing room are all clad in plywood sealed with clear lacquer, with further skylights included above the dressing room, shower and WC.

Brick masonry was used to create robust flooring and walls in the utility room, WC and family bathroom, offering a connection to the original exterior facades.

Photography and movie are by Nicholas Worley.