Catslide House

astula-architecture, LEWES, 2017


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10 Balustrade filtering light 

Julian Hill     Download Original

  • 10 Balustrade filtering light    
  • 01 Bringing light in    
  • 02 Triple height space    
  • 03 At the top    
  • 04 Shades of grey    
  • 05 Concealed stair    
  • 06 Shades of white    
  • 07 Old and new    
  • 08 New stair    
  • 09 Round corner    
  • 11 New mezzanine    
  • 12 Secret pasage    
  • 13 New bathroom-IBM.jpg    
  • 14 Complex geometry    
  • 0 - ground floor plan.pdf    
  • 1 - first floor plan    
  • 2 - attic floor plan    
  • 3 - section    
  • 01 Top landing    
  • 02 Shower template    
  • 03 Shower former    
  • 04 From the top    
  • 05 Sweeping curve    
  • 4 - bathroom    

Bringing light into a dark 1930s house, making the most of under-used roof spaces

Magali McKay of astula-architecture has made the most of the unusual shape of this 1930s semi-detached house, opening up the first-floor landing – both upwards towards the sky and sideways into the catslide-roof space – and transforming the feel of the house by giving it a new triple-height space at its heart. Eyes are instantly drawn upwards to a new sweeping half-wall that leads up to a top-floor bedroom, and this new curve also picks up on the opposite wall’s rounded corner, a strong original feature of the house.

Light from two rooflights now floods the centre of the house all the way down to the entrance hall. A lovely little dormer previously hidden from view has been exposed, and the stairwell now offers a generous and welcoming space. Three virtually invisible cupboards hide behind the tongue-and-groove panelling that wraps around the eaves.

The owners’ eleven-year-old son has been the lucky recipient of a new top-floor bedroom just visible behind a birch-ply balustrade, and, with a little window beside his bed to look onto the landing below, his room retains its connection to the rest of the house while giving him his very own space away from the other bedrooms.

The small room he previously occupied has become a ‘secret’ en-suite bathroom for his parents. Now accessed via a tunnel-like opening from the master bedroom, it is concealed behind new cupboard doors. The shape of the bathroom is defined by the sloping ceiling of the catslide roof, the curved wall of the walk-in shower and the chimney stack.

As soon as you step into the house, you become aware of its sheer height. But it’s a house that surprises everyone who ventures further in, with its carefully considered geometry, bright and open landing, and secret spaces beyond.


  • Completed: Jul 2017
  • Floor area: 60m2
  • Sector: Residential
  • Total cost: £80,000
  • Funding: Private
  • Address: Brendon, Rotten Row, LEWES, BN7 1LJ, United Kingdom

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