Independent Place

This Dalston property was originally designed as two live/work units.  Now combined, it had been unsympathetically extended and the clients were keen to explore a new solution to extend their living space. [pictures: French + Tye]


The existing conservatory benefited from substantial concrete foundations, and instinctively it seemed prudent to retain and reuse these.  Doing so greatly reduced the risk of unknowns in the ground, and also provided a cost and time saving during construction.  The foundations, concrete slab and even existing slate tiled finish were retained as existing.


We worked with structural engineers Structure Mode from an early stage of the project which allowed us to carefully assess viability.  In principle a new structure on the existing foundations could be justified by offsetting the weight of the existing conservatory, but the new structure would need to be lightweight.


The property has a constrained rear garden, and the form needed to respond to the need for subservience to the neighbouring property.  The site faces south, and the existing conservatory suffered terribly from overheating.


The solution is a double curved, self-reciprocating, cantilevering composite timber roof structure.  The roof curves in both directions, creating two lower corners towards the adjacent neighbour.  The curves also give the roof structural integrity for overhanging to shade the glazed elements.   The roof tips up towards the south facing full height glass-to-glass corner.


Each roof beam is CNC cut in sections from a Laminated Veneered Lumber (LVL) panel.  These panels are typically used in prefabricated house construction.  The design utilises the unique cross lamination layout of the panels, with timber grain running both perpendicular and at forty-five degrees within the panels.  This additional grain direction is dimensionally stable and gives each beam its strength along each unique curve.


Iterative design development at 1:10 scale informed the depth and span of the structural roof grid.  Mortice and tenon joints are cut within half the depth of each beam.  Each mortice and tenon connection runs through a hole in a corresponding perpendicular beam.  This results in a connection detail that is self-reciprocating: it rests on itself and supports itself simultaneously.  The load bearing capacity of the LVL panel assists with this detail.

Externally the roof tapers to create a neat edge and steel connections are left exposed.  Three layers of thin plywood are secretly screwed down onto the exposed lattice roof structure from above to create a roof deck which is then insulated.  This allows the entire depth of timber roof beams to be exposed internally.



The roof is supported along one edge, and then on six square columns.  Cross bracing of structure was limited to three zones to allow substantial glazing.  Steel beams in the ground pick up and spread the load of each column onto the existing foundations.






Clerestory glazing to three sides is situated externally of the structural frame and brings light in whilst retaining privacy.  Whilst large doors bring the garden in, a small window can tilt to provide secure ventilation.

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